⚠️ Safety First During Troubleshooting

Always disconnect battery before working on electrical systems. If weapon is installed, all powered testing must be done inside a test box. Use proper test equipment and never bypass safety systems. Work in well-lit areas and keep your workspace organized.

Systematic Diagnostic Process

Follow this methodical approach to isolate problems quickly and avoid unnecessary work.

Step-by-Step Diagnosis

1. Power System Check
Verify battery voltage (11.1V+ for 3S LiPo), main switch operation, and LED indicators on all ESCS and receiver (some ESCS do not have an LED). Most failures start with power issues.
2. Visual Inspection
Look for loose connections, damaged wires, burnt components, or mechanical damage. Many problems are visible.
3. Continuity Testing
Set multimeter to continuity mode (speaker symbol). Touch probes together to hear confirmation beep. Test each wire from end to end - you should hear a beep if the connection is good. No beep means broken wire or loose connection. Use this to confirm each board is receiving power.
4. Component Isolation
Disconnect components one by one to isolate the failed part. Start with most recently added or modified components.
5. Component Replacement
Replace each individual component one by one to diagnose the failure point. Multiple components may need replacing.

Electrical System Failures

Most electrical problems fall into predictable categories with systematic solutions.

Key Electrical Measurements

2S LiPo (7.4V nominal): 8.4V fully charged, 6.0V minimum under load
3S LiPo (11.1V nominal): 12.6V fully charged, 9.0V minimum under load
Single cell voltage: 4.2V max charge, 3.0V minimum discharge
Brushed motor resistance: 1-10 ohms typical, infinite resistance to ground
Voltage drops: Should not exceed 0.2V across any single connection
Servo signal: 1000-2000μs pulse width, 50Hz frequency
Complete Power Loss

Robot shows no signs of life, no LEDs, no response.

Solutions:
  • Check battery voltage and charge level
  • Verify main switch connection and operation
  • Inspect motor wires
  • Test power distribution wires
Intermittent Operation

Robot works sometimes but cuts out randomly.

Solutions:
  • Check for loose or corroded connections
  • Search for cold solder joints
  • Verify battery connector integrity
  • Test under vibration or movement
ESC Beeping Continuously

Speed controller emits error beeps and won't arm.

Solutions:
  • Recalibrate ESC/ Arm ESC with transmitter
  • Check signal wire connection to receiver
  • Verify transmitter settings (endpoints)
  • Test with known good receiver
Motor Runs Wrong Direction

Motor spins opposite to intended direction.

Solutions:
  • Swap any two motor wires (brushless / brushed)
  • Reverse transmitter channel (DO NOT REVERSE WEAPON CHANNEL!)
  • Check transmitter mixing

Mechanical System Failures

Mechanical problems often have visible symptoms and straightforward solutions.

Wheels Slipping on Hubs

Drive wheels lose grip on motor shafts during operation.

Solutions:
  • Tighten shaft collar set screws
  • Use thread locker on set screws
  • File flat spot on motor shaft
  • Replace worn hub with tighter fit new hub
Binding or Grinding Noises

Robot makes unusual noises during movement.

Solutions:
  • Check for debris in drive system / motor gearbox
  • Inspect bearing wear or damage
  • Verify proper component alignment
  • Lubricate moving parts if appropriate
Cracked or Broken Parts

3D printed components show stress fractures or breaks.

Solutions:
  • Super glue for small cracks
  • Tape reinforcement for temporary fixes
  • Replace with spare parts when available
  • Use soldering iron to fuse broken pars together
Weapon Won't Spin Up

Spinner weapon fails to reach operating speed.

Solutions:
  • Check motor mounting and alignment
  • Verify weapon is balanced properly
  • Inspect for damage to motor itself
  • Test motor separately from weapon
  • Ensure mounting screws do not touch motor windings

Radio & Control Issues

Radio problems can be subtle but have systematic diagnostic approaches.

Failsafe Not Working

Robot doesn't stop when transmitter is turned off.

Solutions:
  • Reconfigure failsafe settings on receiver and on transmitter
  • Verify receiver supports failsafe
  • Test failsafe operation thoroughly
  • Check ESC failsafe configuration
Won't Bind to Transmitter

Receiver fails to establish connection during binding.

Solutions:
  • Try different receiver number/slot
  • Hold bind button throughout process
  • Ensure compatible protocols
  • Reset transmitter to factory defaults
  • Test new receiver / new transmitter

Event-Day Quick Fixes

Fast repairs when you're at competition and time is limited.

  • Loose wire: Solder wires together as fast as possible.
  • Cracked part: Use solder iron to fuse parts together. Super glue or tape reinforcement if needed
  • Missing screw: Zip tie, glue, or tape as emergency fastener
  • Dead receiver: Swap from backup robot or borrow from teammate
  • Motor binding: Clear debris from gearbox, check for damaged bearings. Switch to new motor to save time.
  • Battery connector loose: Tape the XT30 connectors to prevent lipo unplugging
  • Switch failure: Peplace with removable link if allowed
  • ESC dead: Replace with spare or run single motor temporarily

Essential Pit Tools

  • Electrical: Multimeter, soldering iron, spare wire, Electrical tape
  • Mechanical: Hex keys, screwdrivers, zip ties, super glue
  • Spares: Bring 1 extra of each component if possible. Print multiple weapons/armor pieces.