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When the drone needs work.

Field repairs determine whether a failure costs you a day or a week. This page is the symptom-driven catalog: you describe what's wrong, the page leads you to the likely cause, then to the procedure for fixing it. Calibrated for cohort default 5"/7"/10" builds and the typical problems graduates see in their first year of operations. The goal is to keep working drones in the air; the alternative is sending each broken drone to a repair shop and waiting weeks for it to come back.

Version 1.0 · Updated 05·2026 Author: Lumipad Engineering License: CC-BY-SA-4.0 Languages: EN · TL · CEB

Symptom-first, then component, then escalation.

Most repair work starts the same way: the drone is doing something wrong, and you need to figure out what. Sections 2-4 are organised by symptom — find your symptom, follow the diagnostic path. Section 5 is organised by component for when you already know what needs replacing. Section 6 covers tools, spares inventory, and the cases where field repair isn't the right answer.

The procedures in this page assume cohort default 5"/7" INAV builds or 10" ArduPilot builds. Other builds may share the same components but differ in specifics. The downloadable repair pack at the top of this page provides printable flowcharts and reference cards for in-field use when the page itself isn't accessible.

Section 01 The diagnostic mindset before specifics

The repair workflow.

Before any specific repair: the diagnostic approach that makes specific repairs work. The most common repair mistake is replacing the wrong part — a vibration is blamed on a motor when the issue is a bent prop; a "dead FC" is replaced when the issue is a corroded USB cable. Cohort default workflow: identify the symptom, isolate the cause, then act.

The four-step diagnostic flow:

Step What you do Common mistake Cohort approach
1
Observe carefully What exactly is the symptom? When does it happen? Is it consistent or intermittent?
Skipping observation; jumping to the most-recently-seen-on-Discord cause.
Spend 2 minutes describing the symptom in writing before touching anything. Specificity reveals the cause.
2
Isolate variables Test one thing at a time. If you change two things and the issue resolves, you don't know which fix worked.
Trying multiple fixes simultaneously; can't reproduce the working state later.
One change → test → record outcome → next change. Slower but produces real knowledge.
3
Verify the fix After repair, test under the conditions that caused the original symptom.
Hover-tested only; declared fixed; symptom returns during real flight.
Test progressively: bench check → tethered hover → free hover → controlled flight → mission rehearsal. Each level confirms before the next.
4
Document what you learned Field repair logbook: symptom, cause, fix, lessons. Becomes your personal reference for next time.
Memory is unreliable; the same problem recurs and the graduate re-debugs from scratch.
5-minute logbook entry per repair. Pattern emerges across entries: which problems are common, which are rare, which prevention strategies work.

Repair vs replace: the cohort decision tree

Should you repair the broken thing or replace it? Cohort default thresholds:

  • Repair if: cost is under 30% of replacement; you have the skill or are willing to learn; the part isn't safety-critical (e.g., props are repair-or-replace; FC is replace if uncertain).
  • Replace if: cost is over 50% of replacement; the repair is uncertain and the failure mode is dangerous; you need to fly tomorrow and don't have time for a careful repair.
  • Repair the practice piece, replace the working piece: when learning a new repair (e.g., motor lead resoldering), practice on retired parts before working on a flying drone.

The bias for first-year graduates: repair more than you think you should. The skill develops through practice; sending every problem to a repair shop never builds the capability. The cohort-recommended progression: try the repair; ask for help on graduates Slack; only escalate to a shop if both fail or safety is at stake.

The cohort spares-on-hand rule. The repair workflow assumes you have parts available. Cohort default minimum spares inventory:

  • Propellers: 4 sets minimum; 6 sets if you fly often. ~₱200/set.
  • One spare motor matching your build. ~₱1,200.
  • One spare ESC matching your build. ~₱1,500.
  • USB cables: at least 2 spares; data-capable, not charge-only. ~₱150 each.
  • Hex drivers, soldering iron, pliers: in the field bag.
  • Heat shrink and electrical tape: small packet of each.
  • Multimeter: ₱600-1,200 for a workable model.

Total cohort default spares investment: ~₱5,000-7,000. Pays for itself the first time it saves a mission.

Section 6 covers full tools and spares inventory in detail.

Section 02 When the drone won't even start

Power and no-arm symptoms.

The drone doesn't power on, or powers but won't arm, or arms but motors don't spin. These are the easiest categories to diagnose because the drone is stationary and accessible. The trade-off: many possible causes, requiring systematic narrowing rather than instant recognition.

Symptom: drone has no signs of life. No LED on FC, no ESC beeps, nothing.

Cause How to test Fix Cost and time
A1
Battery dead or disconnected The most common cause. Battery may have self-discharged, or connector is loose.
Multimeter on battery: should read >13V for 4S, >19V for 5S, >22V for 6S. Check XT60 connection visually and by reseating.
Charge battery; reseat connector; verify with multimeter. ~5 min.
Free; only time.
A2
XT60 connector damage One of the spade contacts may be loose, bent, or oxidised. Hidden inside the plastic housing.
Wiggle the XT60 connector while watching for FC LED flicker. Visual inspection of internal contacts (need to disassemble carefully).
Replace the XT60 — solder a new one onto the battery wires. ~30 min including teardown.
~₱100 for the connector. Skill: basic soldering.
A3
Power lead failure Wire from XT60 to FC has broken internally. Most often at the connector or where the wire flexes.
Multimeter continuity test on the lead. Wiggle while testing — a wire that's broken under insulation will show intermittent continuity.
Replace the power lead — desolder old, solder new wire (silicone insulation, 14-16 AWG). ~45 min.
~₱150 for wire. Skill: soldering.
A4
FC dead Flight controller has failed entirely. Rare but happens — usually water damage, voltage spike, or end-of-life.
After ruling out A1-A3: try connecting via USB. If FC powers from USB but not battery, may be VBat circuit damage. If FC doesn't power from USB either, FC is dead.
Replace the FC. Reflash firmware; restore configuration from backup (firmware.html).
~₱2,500-4,500 for replacement. Reflash and reconfig: ~3 hours.
A5
BEC failure On-board voltage regulator has failed. Battery is fine, FC partially powers, but 5V/3.3V rails are missing.
Multimeter on FC's 5V pad: should read 4.9-5.1V. If 0V or wrong voltage, BEC has failed.
If BEC is on FC, replace FC. If BEC is separate (some 10" builds), replace BEC module.
FC: ~₱2,500-4,500. Separate BEC: ~₱600.

Symptom: drone powers on but won't arm. FC LED on, ESCs beep, but the arm switch does nothing.

Cause How to test Fix Cost and time
B1
Pre-arm check failing FC is refusing to arm because a safety check failed: GPS, mode switch position, throttle position, calibration.
Connect to configurator. Look at the arming flags — the FC tells you exactly which check is failing.
Address the specific failure: wait for GPS lock, set switch to correct position, calibrate accelerometer, etc. fc-setup.html Section 10 covers all 22 pre-arm checks.
Free; ~5-15 min depending on the cause.
B2
Receiver not bound or signal lost FC isn't receiving valid stick inputs from the radio.
In configurator, watch the Receiver tab while moving sticks. Stick movements should show as bars moving.
Re-bind receiver to radio. Verify channel order matches FC expectations (AETR or TAER). fc-setup.html Section 5.
Free; ~10-20 min.
B3
Failsafe stuck FC believes it's in failsafe state because of a previous incident; arming is blocked.
Look for failsafe indicator in configurator. Reboot FC; reconnect; check again.
Power-cycle the FC (disconnect battery for 10 seconds, reconnect). If still stuck, factory-reset and reload config from backup.
Free; ~15-45 min depending on whether reload is needed.
B4
Configuration corruption FC settings have become inconsistent — usually after a botched firmware update or interrupted save.
Configurator may show error messages or unusual values. Compare against backed-up config.
Factory reset; reload cohort default config dump; re-verify settings. fc-setup.html Section 9.
Free; ~30-60 min.

Symptom: drone arms but motors don't spin (or one motor doesn't spin).

Cause How to test Fix Cost and time
C1
Throttle calibration off ESCs aren't recognising the throttle range; minimum stick isn't triggering motor start.
In configurator Motors tab: try the motor sliders directly. If sliders work but throttle doesn't, calibration is the cause.
Run motor calibration procedure (in configurator) or set throttle endpoints to ESC defaults (1000-2000 PWM). fc-setup.html Section 4.
Free; ~10 min.
C2
ESC signal wire damaged One ESC isn't receiving signal from FC. Affects only one motor, not all four.
In configurator Motors tab, slider for the affected motor produces no response. Visual inspection of signal wire from FC to ESC.
Resolder signal wire; replace if damaged. ESC pads on FC sometimes need cleanup; verify good solder joint on both ends.
Free if just resoldering; ~30-45 min including disassembly.
C3
ESC firmware mismatch ESC running incompatible firmware version, common after FC firmware updates without ESC update.
Check ESC firmware version (configurator Configuration → ESC). Compare against current FC firmware compatibility.
Update ESC firmware to compatible version. firmware.html Section 4 covers ESC firmware ecosystems.
Free; ~30-60 min.
C4
ESC dead One ESC has failed. Magic smoke, scorched component, or just no signal response.
After ruling out C1-C3: ESC pad voltage check, visual inspection for burnt components.
Replace the ESC — desolder old, solder new ESC. Component-level Section 5 covers procedure.
~₱1,500 for replacement ESC. Skill: soldering.
C5
Motor dead Motor windings have failed; ESC is sending signal but motor doesn't turn.
Spin the motor by hand (with ESC disconnected). If smooth, motor is mechanically OK; issue may be electrical. Multimeter resistance check on three motor leads (should be similar between leads).
Replace the motor. Component-level Section 5 covers procedure.
~₱1,200 for replacement motor. Skill: soldering, motor swap.

The "blame the FC" trap

When something's wrong and you can't figure out why, the temptation is to blame the FC and replace it. The FC is rarely the actual cause. program graduates reports show that:

  • ~70% of "FC dead" diagnoses turned out to be: power lead damage, USB cable issues, or configuration corruption.
  • ~20% turned out to be: ESC issues affecting FC behavior.
  • ~10% were actually FC failures.

Before replacing an FC: try a different USB cable; test power at the FC pads with multimeter; reload firmware; factory-reset and reload config. The FC is the most expensive component to replace and the rarest actual failure point. Diagnose carefully before assuming the worst.

Section 03 When the drone flies but flies badly

Flight behavior symptoms.

The drone takes off but something is off — vibration, drift, won't hold altitude, yaws unexpectedly. These symptoms can be subtle and intermittent, which makes them harder to diagnose than power issues. Most flight-behavior issues come from props, motors, FC mounting, or configuration. Section 5 covers the component-level repairs once the diagnosis is clear.

Symptom: vibration in flight. Drone shakes visibly or in FPV; OSD readings jitter; image quality degrades.

Cause How to test Fix Likelihood
V1
Damaged or unbalanced prop Most common cause. Prop has tiny chips or imbalance you can't see at rest but matter at 20,000 RPM.
Visual inspection with strong light; spin each prop in your fingers and feel for wobble. Replace if any doubt.
Replace the prop set. Cohort default: replace all 4 props at once even if only one is suspect. ~₱200.
~50% of vibration causes
V2
Bent prop shaft Motor shaft is slightly bent from a previous crash. Prop spins eccentrically.
Spin motor by hand with prop removed; watch for visible wobble. Compare with another motor.
Replace the motor (shafts can't be reliably straightened in the field). Section 5 procedure.
~25% of vibration causes
V3
Loose motor mount Screws holding motor to frame have loosened from vibration over time.
Try moving each motor by hand; should feel completely solid. Check screw torque.
Tighten motor mount screws; apply thread locker (blue) to prevent recurrence. ~10 min.
~15% of vibration causes
V4
FC mounting too rigid or too loose FC vibration isolation is wrong. Hard mounting transmits prop vibration; loose mounting lets FC bounce.
Check FC mounting standoffs and dampers. Should be firm but with slight give.
Replace soft mounts (foam standoffs / o-rings). Cohort default: medium-firm rubber dampers, ~₱100.
~7% of vibration causes
V5
Worn motor bearing Motor bearing has degraded; spins less smoothly.
Spin motor by hand; should be smooth and quiet. A grinding or grating feel indicates bearing wear.
Replace the motor (cohort default; bearing replacement is possible but not field-practical for most motors).
~3% of vibration causes

Symptom: drone drifts unexpectedly in Position Hold.

Cause How to test Fix Notes
D1
GPS lock weak Position Hold needs strong GPS lock; weak lock causes drift.
Check satellite count on OSD: should be ≥10 for solid hold. HDOP under 1.5.
Wait for stronger lock before takeoff; relocate GPS module if it's shielded by carbon frame.
Most common drift cause; usually environmental, not equipment.
D2
Compass calibration off FC's magnetic heading reading is wrong, so position-hold corrections move the drone the wrong direction.
Check compass calibration in configurator. Magnetic interference around launch zone (vehicles, structures, power lines) can affect this.
Re-calibrate compass at the flying site. fc-setup.html Section 6 covers procedure.
Re-calibrate when flying location changes significantly.
D3
Wind exceeding capability Position Hold tries to compensate but can't; drone drifts downwind.
Check wind on the day; cohort default 5" build limits to ~25 km/h sustained.
Don't fly above wind threshold; switch to Angle for manual control if caught out.
Not a repair issue; an operational decision.
D4
Accelerometer not level FC thinks "level" is slightly off-axis, so neutral-stick produces a slight drift.
Re-calibrate accelerometer on a verified level surface.
Configurator → Calibration → Accelerometer. Place drone on flat surface; calibrate. ~5 min.
Should be done after any frame work or hard landing.

Symptom: drone yaws (rotates) unexpectedly.

Cause How to test Fix Notes
Y1
Motor mounting direction wrong One motor spinning the wrong direction. FC compensates with constant yaw input.
After arming, check motor rotation directions in configurator Motors tab. Compare against the cohort default rotation diagram.
Reverse the affected motor — swap any two of the three motor wires. ~15 min.
Common after motor replacement.
Y2
One motor weaker than others One motor produces less thrust than the other three. FC compensates but creates yaw drift.
Hover-test, look at FC motor outputs. One motor running noticeably harder = weaker physical motor.
Replace the weaker motor. Often paired with damaged bearings (V5 above).
Common after one prop strikes ground harder than others.
Y3
Yaw PID tuning off Configuration issue, not hardware. Drone yaws because yaw response is poorly tuned.
Check tuning.html Section 4 for yaw-specific PID values. Compare against cohort default.
Re-tune yaw PIDs. Often a P-term increase resolves drift.
More common on aged builds where setting drifted from defaults.

The systematic isolation principle

Flight behavior issues often have multiple contributing causes simultaneously: damaged prop + slightly loose motor mount + weak GPS lock. The temptation is to fix everything at once. Don't.

Cohort default approach: fix one thing → test → fix next thing → test. Even if you're sure all three are issues, this sequence tells you which fix mattered. Without that knowledge, you can't predict whether the next similar symptom needs the same fix or a different one.

Specific exception: props always get replaced as a set. Don't mix old and new props on the same drone; the imbalance creates harder-to-diagnose vibration issues.

Section 04 Systematic checking after any crash

Post-crash inspection.

Crashes (covered by emergencies.html Section 3 for immediate response) leave damage. Some is obvious — broken props, scuffed frame. Some is subtle and only manifests during the next flight: a hairline arm crack, a slightly bent shaft, a dislodged FC standoff. The post-crash inspection is the systematic walk-through that catches subtle damage before it causes another crash.

The cohort default post-crash inspection sequence — done before any attempt to fly:

Step What to inspect Pass criteria If fail
1
Frame structural Look for cracks, especially at arm-to-body joints. Carbon frames crack along grain; visible as thin white lines.
No visible cracks. Arms feel rigid when flexed gently. No twist or bend.
Replace cracked arms or full frame. Cracks always grow; flying with a cracked arm leads to in-flight failure. ~₱500-1,500 for arm; ~₱2,500-4,000 for full frame.
2
Motor shafts Spin each motor by hand with prop removed. Look for wobble or grinding feel.
Smooth spin in all four motors. No visible wobble. No grit or grinding feel.
Replace bent-shaft or damaged-bearing motors. Don't try to straighten shafts; they fail again under load.
3
Propellers All 4 props inspected for cracks, chips, or any damage. Cohort default: replace all 4 even if only one looks damaged.
No cracks, chips, or visible damage. Props balance evenly when held by hub and tilted.
Replace as a set. ~₱200/set. Cheapest insurance against next-flight vibration issues.
4
FC mounting FC firmly mounted; no broken standoffs; no shifted position.
FC sits firmly. All 4 standoffs intact. No visible movement when frame is flexed.
Replace standoffs (~₱150 set); reseat FC; verify accelerometer calibration after mounting work.
5
Wiring and connectors All wires intact, no exposed copper, no abrasion. XT60 and motor connectors firm.
Visually trace every wire. No cuts, no bare conductor, no broken insulation.
Repair specific damage: heat-shrink small cuts, replace severely damaged wires, resolder loose connectors.
6
Receiver antennas Antenna wires intact, not abraded. Fragile after impact.
Antennas in their original position; no exposed copper at tips; no kinks or breaks.
Replace receiver if antennas are severely damaged (~₱600). Re-route if just dislodged.
7
GPS module Module attached securely; wire to FC intact.
Module firmly mounted; wire connection solid; cable no abrasion.
Re-mount if loose; replace if module shows damage. ~₱600.
8
Camera/lens Lens intact; mount secure; cable to FC undamaged.
Lens unbroken; image clear when powered. Mount secure.
Replace cracked lens (~₱200) or damaged camera (~₱1,500). Reseat if loose.
9
Battery Pack visually intact; no swelling; voltage normal.
No swelling, no soft spots, no smell. Voltage matches expected range. No heat.
Retire pack from service if any concerning signs. emergencies.html Section 5 covers LiPo disposal.
10
Power-on test (no props) With props removed, power on the drone. Check FC behavior, ESC initialization, sensor readings.
FC powers normally, ESCs initialize with normal beep pattern, configurator shows expected sensor values.
Address any anomalies before continuing. Configuration may need reload from backup.

The "tested at home, fails in field" trap

A common pattern after repair: the drone tests fine in the workshop but fails during the next mission. Causes:

  • Hover-only testing. Many post-crash issues only manifest at higher motor loads (forward flight, climbing, mission speeds). Test progressively, not just hover.
  • Indoor vs outdoor differences. Indoor: no GPS, no wind, magnetic interference from buildings. Test outdoors at the actual flying altitude.
  • Cold start vs warm start. Some issues only appear when components warm up or cool down. Don't skip the warm-up flight after extended workshop work.
  • Battery sag. Repaired drones may behave differently under low-voltage conditions. Test through a full battery, not just the first 2 minutes.

Cohort default progressive test sequence after any repair: bench check → tethered hover (props on, drone tied to ground) → free hover → controlled forward flight → mission rehearsal → first mission. Each level confirms before the next. ~30-45 minutes total; saves the cost of a second crash.

Document the crash. While doing the inspection, take photos and notes:

  • Photos of all damage (before any repair work).
  • Notes on what conditions led to the crash.
  • Suspected cause (best current understanding).
  • What was repaired or replaced.
  • Verification steps and outcomes.

This documentation feeds into the cohort incident record (emergencies.html Section 6) and into your personal field log. Patterns emerge over multiple crashes: certain conditions, certain components, certain operational mistakes. Pattern recognition is what makes graduates operations safer over time.

Section 05 Once you know what to fix

Component-level repairs.

When the diagnosis is clear and you have the part on hand, the actual repair procedure varies by component. This section is the reference for the most common repairs in cohort default operations: prop replacement, motor swap, ESC swap, FC swap, frame arm replacement. The procedures assume basic soldering skill (developed during the build phase) and the cohort default tool kit.

Repair time and cost summary (cohort default 5"/7" builds, fresh-cohort-alumna pace):

Repair Time Cost (parts only) Skill required
PROP
Propeller replacement (set of 4) Remove old props with hex driver, install new ones in correct rotation pattern (CCW/CW).
~10 min
~₱200/set
Trivial; no soldering.
MOT
Single motor swap Remove old motor (4 screws), desolder 3 motor leads from ESC, solder new motor leads, reinstall, verify rotation direction.
~45-60 min
~₱1,200/motor
Basic soldering. Most common skilled repair after prop replacement.
ESC
Single ESC swap (4-in-1 build) More involved on cohort default 4-in-1 ESCs: requires disassembly to access ESC board.
~90-120 min
~₱1,500-2,500
Intermediate soldering; tight access. May want to escalate (Section 6).
FC
FC replacement Disassemble drone, desolder FC connections (8-12 wires), solder new FC, reflash firmware, restore configuration.
~3-4 hours
~₱2,500-4,500
Intermediate soldering, configuration knowledge. Major repair.
ARM
Frame arm replacement Disassemble frame to access broken arm, swap with new arm, reassemble. Requires removing motor and ESC connections from that arm.
~2-3 hours
~₱500-1,500
Mostly mechanical; some soldering for motor leads.
RX
Receiver replacement Desolder old receiver wires (3-4), solder new receiver, re-bind to radio, configure in FC.
~60 min
~₱600/receiver
Basic soldering plus binding procedure.
GPS
GPS module replacement Desolder old module wires (4), solder new module, re-mount, verify lock.
~45 min
~₱600-1,200
Basic soldering. Common after crashes that hit the top-mounted GPS.

Motor swap procedure (the most common skilled repair):

  1. Remove props. All four, not just the affected motor's. Safety first.
  2. Disconnect battery. Verify by checking FC has no LED.
  3. Document original motor wiring: photo of the three motor leads connected to ESC pads. Order matters for rotation direction.
  4. Desolder motor leads from ESC pads. Heat the joint, lift the wire away. Don't pull on the wire while solder is solid.
  5. Remove the motor: 4 screws from underside of arm. Set aside.
  6. Install new motor: align with arm, install screws (don't over-tighten). Apply blue thread locker to screw threads.
  7. Strip and tin new motor leads: ~3mm of insulation; thin coat of solder on the bare wire.
  8. Solder leads to ESC pads: same connection pattern as documented in step 3. Solid solder joints; not blobs, not pinpoints.
  9. Heat shrink each joint: small piece of heat shrink over each connection; heat to shrink. Prevents shorts.
  10. Test motor rotation direction: in configurator, command the new motor at low throttle (props still off). If wrong direction, swap any two of the three leads.
  11. Reinstall props in correct CW/CCW pattern.
  12. Bench test at low throttle; verify all four motors spinning correctly.
  13. Tethered hover test; then free hover; then controlled flight.

Solder joint quality

Drone repairs depend on solid solder joints. Bad joints cause intermittent failures that are extremely hard to diagnose. Cohort default checks for a good joint:

  • Shiny appearance: dull joints suggest cold solder (insufficient heat). Re-flow with more heat.
  • Concave fillet: solder should curve smoothly between wire and pad, not blob.
  • Wire fully wetted: solder visible filling the strands of the wire, not just the surface.
  • No pulling test: gently tug the wire. If it moves, the joint is weak.
  • Time at temperature: 1-2 seconds with hot iron, no longer. Excessive heat damages pads.

If you're new to soldering, practice on retired components before working on flying drones. Failed solder joints are responsible for ~30% of repair-induced crashes — the second crash that follows the repair of the first crash. Skill development is worth the time investment.

The other component-level procedures follow similar patterns: document original state, disconnect carefully, install new part, reconnect with attention to wiring, verify before flight. The downloadable repair pack includes step-by-step photo guides for the cohort default 5"/7"/10" builds; this page focuses on the workflow rather than reproducing every photo.

For repairs not covered here (gimbal swap, antenna repair, custom payload work, structural rebuilding): the cohort approach is to ask in the graduates Slack. Other operators have done these; their documented procedures often save hours of trial-and-error. Cohort engineering also maintains repair guides for less-common procedures available to current cohort members.

Section 06 Tools, spares inventory, and when to escalate

Tools, spares and escalation.

The repair workflow assumes you have tools and parts. This section is the reference for what to keep on hand — the cohort default workshop and field-bag inventories. It also covers the cases where field repair isn't the right answer: when to escalate to a Davao repair shop, when to ship to a regional service centre, when to retire a build entirely.

Cohort default workshop tool kit (one-time investment for any alumna doing their own repairs):

Tool Purpose Cost (PHP) Notes
SOL
Soldering iron + station Temperature-controlled iron, ideally 60W+. Hakko or compatible.
~₱1,800-2,500
Don't skimp on this. Cheap irons can't hold temperature; produce bad joints.
MULTI
Multimeter Voltage, continuity, resistance testing. Auto-ranging digital model.
~₱600-1,200
Continuity beep is the most-used feature; verify it works.
HEX
Hex/Allen driver set Sized for cohort default screws (1.5mm, 2mm, 2.5mm, 3mm).
~₱400-800
Magnetic tips help with small screws.
PLI
Needle-nose pliers, wire strippers, side cutters Wire prep and small-component handling.
~₱600-1,000 set
Quality wire strippers save time on every soldering job.
DESOL
Desoldering wick or pump Removing solder from pads when desoldering components.
~₱200-500
Wick is more forgiving for beginners; pump is faster for experienced repairs.
MAG
Magnification (loupe, head-mounted, or USB microscope) Inspecting solder joints, finding small damage.
~₱300-2,500
Cheap loupe is fine for starting; USB microscope nice if you do a lot of repairs.
VICE
Helping hands or PCB vise Holds work steady during soldering.
~₱500-1,500
Saves frustration and reduces bad joints from work moving during soldering.

Total workshop tool investment: ~₱4,500-9,000 for the full cohort default kit. Pays for itself within 2-3 repairs vs sending to a shop.

Cohort default field-bag spares (carried on every mission for in-field repairs):

  • 4 sets of props matching your build (~₱800).
  • 1 spare motor matching your build (~₱1,200).
  • 1 spare ESC (if not 4-in-1; otherwise carry whole spare 4-in-1) (~₱1,500-2,500).
  • 2 spare USB cables data-capable (~₱300).
  • Hex driver set for in-field tightening.
  • Small soldering iron + butane torch for emergency in-field soldering (rare but valuable, ~₱800).
  • Heat shrink, electrical tape, zip ties small assortment.
  • Spare props for visual reference: photos of cohort default rotation directions for the build.

Field bag total: ~₱4,000-6,000. Doesn't replace the workshop kit; complements it.

Decision When Where Cost and time
DIY
Field repair (yourself) Symptoms match what this page covers; you have parts and skill.
~80% of cohort default issues
Workshop or field bag
Parts only; ~30 min to 4 hours.
PEER
Alumni Slack consult Symptoms unclear; specific procedure uncertain; need a second opinion.
When this page or your own knowledge isn't enough.
Online; cohort graduates respond within ~24 hours typically.
Free; mostly time waiting for response.
SHOP
Davao repair shop Repair beyond your skill or tools; or you don't have time. There are 2-3 drone-capable shops in Davao with cohort experience.
Complex ESC repairs, FC pad damage, frame structural welding.
Ask graduates Slack for current cohort-recommended shops.
~₱500-2,500 + parts; 1-7 days turnaround.
REGION
Manila or Cebu service centre Complex repairs not handled in Davao; usually for very specific motors/cameras.
Rare for cohort default builds.
Ship to centre; receive back. Manila or Cebu options exist.
Variable cost + shipping; 2-4 weeks turnaround.
RETIRE
Retire the build Drone has accumulated too much damage; repair cost approaches replacement cost.
Cumulative repair history exceeds ~50% of new-build cost.
Salvage usable components; build a new drone with the cohort default BOM.
Full new build cost (~₱25,000-40,000); 1-2 days assembly time.

When to retire a build entirely

Some drones reach a state where every flight produces new issues. Cohort default signs that retirement is the right call:

  • Cumulative repair cost > ₱15,000 across multiple incidents on the same build.
  • Frame has been repaired 2+ times: arms replaced, body cracked, structural integrity uncertain.
  • FC has been replaced once already: second replacement is rarely worth it; wiring around a replaced FC tends to deteriorate.
  • Vibration issues that don't resolve: suggests deeper structural or motor mounting problems beyond practical repair.
  • You don't trust it anymore: subjective but real. Operators who don't trust their drone fly cautiously, which produces worse imagery and worse decisions.

Retiring a build is not a failure — it's recognising that the build has reached end-of-life. The cohort default lifespan for a 5"/7" build is roughly 100-200 flight hours; some drones last longer, some shorter. Retirement is part of the operational cycle. Salvage usable components (motors, ESCs, FC if recently replaced); recycle the rest; build fresh.

The Davao parts-availability reality: cohort default components are mostly available locally with 1-3 day delivery, but specific items often require longer waits:

  • Available within 1-2 days: cohort default motors, ESCs, FCs, props, batteries (Davao drone shops + Lazada).
  • 2-7 day delivery: specific brands, less-common cameras, specific frame parts (Manila warehouse → Davao).
  • 2-4 weeks: international orders for specialty components (research-grade cameras, specific GPS modules).

The cohort recommendation: maintain spares for fast-moving categories (props, motors, ESCs) so 1-2 day delivery isn't mission-blocking. Specific specialty items can be ordered on-demand because they're rarely needed urgently.

Active cohort members and partner-org operators can access sourcing guidance through the graduates Slack.

Six numbers across repair operations.

Reference values for repair time, cost, and inventory. Useful for budgeting time, parts, and the repair-vs-replace decision.

~80%
Field-repairable issues
Cohort default operations
~₱4,000
Avg repair cost
Vs ~₱25,000 new-build replacement
~10 min
Prop replacement
Most common repair
~45-60 min
Motor swap
Most common skilled repair
~₱5,000-7,000
Cohort spares investment
Field bag + workshop minimums
~100-200 hr
Cohort default build lifespan
Before retirement consideration

Four cases from cohort and partner-org operations.

Specific repair situations from cohort 02 and 03 records, plus partner-org reports. Each illustrates how the diagnostic workflow and decision-making in this page apply in practice.

"The wrong-FC diagnosis."

Current-cohort alumna, post-graduation

Drone wouldn't arm; configurator showed FC connected but FC behavior was erratic. Alumna ordered a replacement FC (~₱3,500) and waited 3 days for delivery. The actual issue: the USB cable used for diagnosis was charge-only, partially confusing the configurator. Original FC was fine. Lesson: rule out the cheap causes (USB cable, power lead, configuration corruption) before ordering expensive replacements. The "blame the FC" trap callout dates from this and similar incidents.

"The growing crack."

Later-cohort alumna, recurring partner cooperative

After a hard landing, frame inspection found a 2mm crack at the rear arm-to-body joint. The alumna assessed it as cosmetic and kept flying. 3 missions later, the arm failed mid-flight; drone crashed, total loss. Lesson: cracks always grow. The 30-minute arm replacement (~₱800 part) would have prevented the loss. Cohort default now: any visible frame crack means immediate retire-from-mission-work; arm or frame replacement before next flight.

"Three-fix isolation success."

Current-cohort graduate, 7" build

Drone yawing slowly during forward flight. Three suspected causes: prop damage, weak motor, yaw PID needing adjustment. The graduate fixed each one separately, testing between: replaced props (no improvement) → tightened motor mounts (slight improvement) → re-tuned yaw PIDs (issue resolved). Total time: 3 hours across two days with clear verification. Lesson: systematic isolation works. If he'd done all three at once, he'd never have known the PIDs were the actual issue — the same problem would recur on the next build.

"The retirement decision."

Partner-org operator, 7" build with extensive history

Build had ~140 flight hours, 4 hard landings repaired, 1 motor replacement, 1 ESC replacement, 1 frame arm replacement. Cumulative repair cost ~₱11,000. Drone still flew but vibration kept returning despite replacements. Decision: retire the build; salvage motors and FC; build fresh. Total operator time saved over next 6 months estimated at ~30 hours of repair work. Lesson: at some point, repairs stop being economical. Recognising the signal — patterns of recurring issues — is part of operational maturity.

Questions worth answering carefully.

I have no soldering experience. Should I learn or send everything to a shop? +

Learn. The cohort default position is that soldering is a foundational drone-operator skill, not optional specialisation. Reasons:

  • Most repairs need it. Motor swaps, ESC swaps, FC swaps, receiver swaps, GPS swaps — all require soldering. Sending each to a shop is expensive and slow.
  • Field repairs depend on it. A motor wire pulled loose at a remote cooperative is a 30-minute roadside fix with soldering skill; otherwise a return trip.
  • Skill develops with practice. Cohort training includes ~10 hours of soldering practice during build. Post-graduation, ~5 repairs builds genuine competence.
  • Tools are inexpensive. ~₱1,800-2,500 for a usable soldering station + multimeter. Pays back within 2-3 self-repairs.

Cohort training: practice on retired components first; do build assembly with instructor support; first independent repairs on training drones, not flying ones. By 5-10 repairs in, the skill becomes reliable. Don't avoid it — develop it.

What if I make the repair worse than the original problem? +

Possible, especially early. The cohort defaults that minimise this:

  • Document before changing: photos of the original state. If your repair fails, you can return to a known starting point.
  • Practice on retired components: every cohort graduate has a retired drone or two for practice. Try the repair there first; build muscle memory.
  • Test progressively: bench → tethered hover → free hover → controlled flight. Each level catches problems before they become serious.
  • Ask for help: graduates Slack, cohort instructors. Photos of the work-in-progress often catch issues quickly.
  • Know when to escalate: if the repair is genuinely beyond your skill, the Davao shop is a reasonable alternative. ~₱500-2,500 for shop work, fast turnaround. Better than producing an unsafe drone.

Program graduates report ~10% of self-repairs needed a second attempt to get right. The skill develops through this practice; treating each repair as a learning opportunity rather than an expected first-time success.

Should I keep meticulous repair records? +

Yes — but lightweight, not exhaustive. Cohort default repair logbook captures, per repair:

  • Date and which drone (if you have multiple).
  • Symptom (1-2 sentences).
  • Suspected cause (1 sentence).
  • Actual cause if different from suspected (1 sentence).
  • Fix (parts replaced, work done).
  • Cost (parts) and time spent.
  • Verification outcome (test flight result).
  • Lessons learned (1-2 sentences).

~5 minutes per repair entry. Patterns emerge after ~20 entries: which problems are common (almost certainly props and minor crashes), which are rare, which prevention strategies work.

Why this matters beyond personal use: cohort engineering aggregates anonymized repair data across graduates to identify build-level issues. If one specific motor model is failing more than others, the cohort default BOM gets updated. Your repair records contribute to better defaults for future cohorts.

What about water-damaged drones? +

Cohort default is generally to consider water-damaged drones as total losses, salvaging usable components. Reasons:

  • Corrosion is invisible and progressive. Even after drying, water exposure causes long-term failures: corroded solder joints, oxidised pads, intermittent connection issues. Hard to predict; harder to fix all at once.
  • FC and ESCs rarely recover fully. Submersion damage to electronics is usually permanent even when the components appear to work after drying. Failures appear weeks or months later mid-mission.
  • The repair effort exceeds rebuild effort. A water-damaged drone needs every component checked, many replaced, full reflashing — most of a new-build effort.

What can be salvaged: motors (clean and dry; usually recover), frame (no water-damage issues with carbon), props (replace anyway), GPS module (50/50; test before trusting).

Specific exception: if the drone got splashed rather than submerged, careful drying and inspection may produce a working drone. A later cohort had one rain-soaked drone that recovered after 24 hours of drying with rice — but the same alumna doesn't trust pond-submerged drones, and that distinction matters.

What's the cohort recommendation for partner orgs maintaining fleets? +

Partner orgs running 5+ drones need more structured repair operations than individual graduates. Cohort recommendations for fleet maintenance:

  • Centralised workshop: dedicated repair area with shared tools rather than each operator carrying their own workshop kit. Saves ~₱3,000-5,000 per operator while improving repair quality.
  • One designated repair lead: someone who specialises in repair work, supports operators with diagnostic questions, handles complex repairs. Doesn't have to be full-time; ~10-20% of someone's time.
  • Spares inventory at fleet scale: maintain ~2-3x the per-drone spare inventory as a fleet pool. Faster restocking; bulk-order pricing.
  • Per-drone repair logbook: each drone has its own history. Patterns emerge: drone #4 keeps having motor issues; drone #2 is reliable. Informs retirement decisions.
  • Cycle-based maintenance schedule: covered in maintenance.html (proposed). Preventive replacement of parts before failure rather than reactive repair after failure.

The fleet repair operation typically costs ~5-10% of total fleet operating cost. Lumipad engineering can advise specific partner orgs on adapting these patterns; graduates Slack is the contact point.

When does the cohort recommend warranty claims vs self-repair? +

Most cohort default components have no meaningful warranty in Philippine retail context — open-box returns are difficult; "manufacturer defect" claims rarely succeed. Cohort default approach:

  • For new components in first 2 weeks: if there's a clear defect (DOA motor, FC that won't flash), return to seller. Document carefully; some sellers honor exchanges.
  • For components after 2 weeks of use: warranty effectively unavailable. Self-repair or replacement.
  • Specific exception: cohort engineering maintains relationships with several local distributors who do honour defect claims. Available through graduates Slack referrals.

The practical implication: budget for replacements as part of operating cost rather than expecting warranty coverage. The ~₱4,000 average repair cost cited above includes this assumption — no recovery from warranty. Self-reliance is the cohort default.

Should I use generic parts or stay with cohort default brands? +

Cohort default brands are recommended but not required. The trade-offs:

  • Cohort default brands (specific motors, ESCs, FCs cohort engineering has tested): documented compatibility with cohort defaults; graduates Slack support knows them; spares inventory is built around them. Predictable. ~₱500-1,500 more per build than generics.
  • Generic alternatives: cheaper, often equivalent quality, but compatibility issues are your problem to debug. Limited graduates-Slack knowledge.

Cohort recommendations:

  • Stick with cohort defaults for FC and ESCs: configuration complexity rewards using known-good components.
  • Generic motors and props are fine if specs match cohort defaults: KV, weight, prop pitch, etc. Many work as drop-in replacements.
  • Don't mix and match exotic combinations: untested combinations cause issues that are hard to diagnose and not in this page.

The cohort default BOM is calibrated; deviating saves money but adds complexity. For first-year graduates, sticking with defaults is recommended; experienced graduates can deviate as they understand the trade-offs.

What if a repair takes longer than expected and the drone is needed soon? +

Common situation. The cohort defaults:

  • Don't rush a repair. Bad solder joints from haste cause second crashes. The mission can be rescheduled; a crashed drone cannot be unfailed.
  • Reschedule the mission honestly: cooperative manager would rather hear "I had a repair issue, can we move to next week" than receive bad imagery from a marginal drone.
  • Use a backup drone if available. Partner orgs typically maintain backup builds for this reason. Individual graduates may have a 2nd drone (different size, different role) usable as backup.
  • Escalate to a Davao shop for fast turnaround if needed. ~₱500-2,500 for fast service; 1-2 day turnaround vs 1-week self-repair if you're still learning the procedure.
  • Postpone non-urgent missions: practice runs, optional surveys, maintenance flights — these can move. Paid client missions get priority for backup-drone use or shop escalation.

The discipline: flying a drone you don't fully trust is more expensive than rescheduling a mission. The crash, the wasted trip, the damaged client relationship — all costlier than a polite postponement.