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This guide helps you diagnose and fix the most common issues with your OSSM. Start by identifying your symptom, then follow the troubleshooting steps.

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Homing is too slow

If your OSSM homes very slowly or stalls during the homing sequence, the motor may need to be programmed.
1

Check motor programming

The motor requires specific parameters to operate correctly with OSSM. If you assembled the motor yourself or it was reset, you may need to flash the motor firmware.See the motor programming guide for detailed instructions.
2

Verify motor parameters

After programming, the motor should home at a reasonable speed. If problems persist, double-check that all parameters were applied correctly.

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Controller powers on but actuator does not move

When the controller turns on but the actuator remains stationary, the issue is typically related to power delivery, wiring, or belt tension.
Symptoms:
  • Green light on motor is dim or flickering
  • Motor light is visible but actuator doesn’t respond
  • Actuator moves weakly or stalls under load
Solution: Ensure you’re using a power supply that meets the minimum requirements:
  • Voltage: 24V DC
  • Current: At least 5A (10A recommended)
Using an underpowered supply can damage components over time. Always use a supply rated for your motor’s requirements.
Symptoms:
  • Motor light is completely off
  • No response from motor when commands are sent
  • Visible loose or disconnected wires
Diagnosis:
  1. Inspect the wiring between the controller and motor
  2. Check that all connectors are fully seated
  3. Look for damaged or frayed wires
Solution: Reconnect any loose wiring following the wiring guide. If wires are damaged, replace them before operating.
Symptoms:
  • Motor spins but actuator doesn’t move
  • Belt slips or makes noise during operation
  • Inconsistent or jerky movement
Solution: Adjust the belt tension following the tension adjustment guide. The belt should be tight enough to prevent slipping but not so tight that it strains the motor.
A properly tensioned belt should deflect slightly when pressed but return to position immediately.

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Wired remote does not power on

If the wired remote display stays dark when connected, the issue is usually connection timing or a loose cable.
The wired remote draws power from the control board. If you connect the remote before the board is powered, it may not initialize correctly.Solution:
  1. Disconnect the RJ45 cable from the control board
  2. Power on the OSSM using the 24V supply
  3. Wait for the control board to fully boot (LED indicators stabilize)
  4. Connect the wired remote’s RJ45 cable firmly until it clicks
If the remote still doesn’t light up, disconnect the 24V power, wait a few seconds, then reconnect and repeat the steps above.
A loose or partially seated cable can prevent power from reaching the remote.Solution:
  1. Disconnect the RJ45 cable from both ends
  2. Inspect the connectors for bent pins, debris, or damage
  3. Reconnect firmly at both the control board and the remote until you hear/feel a click
  4. Try a different RJ45 cable if available
If the remote worked previously but stopped, a simple power cycle often resolves the issue.Solution:
  1. Disconnect the 24V power supply from the control board
  2. Wait 5–10 seconds
  3. Reconnect the 24V power supply
  4. Allow the board to boot, then check if the remote display activates
If the remote powers on after cycling, no further action is needed. Intermittent issues may indicate a marginal cable connection—try reseating or replacing the RJ45 cable.

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Wired remote lights up but speed control does not respond

If the wired remote display illuminates but the left knob (speed potentiometer) has no effect, the potentiometer component may be faulty.
Symptoms:
  • Remote display turns on and shows the menu
  • Right knob (encoder) works normally for menu navigation
  • Left knob (speed control) produces no change regardless of position
  • No visible damage to the knob or circuit board
Diagnosis:
  1. Power on OSSM and confirm the remote display activates
  2. Navigate menus with the right knob to confirm it responds
  3. Turn the left knob fully counterclockwise to clockwise—if speed never changes, the potentiometer is likely defective
Before concluding the potentiometer is faulty:
  1. Power off and reseat the RJ45 cable at both ends until it clicks
  2. Try a different RJ45 cable if available
  3. Inspect the cable connectors for bent pins or debris
  4. Power on and test again
If the right knob still works but the left knob doesn’t respond, the issue is the potentiometer rather than the connection.
A non-responsive potentiometer indicates a hardware fault that cannot be fixed through software or settings. Contact support to request a replacement wired remote under warranty.Self-repair option: If your remote is out of warranty or you prefer to repair it yourself, the potentiometer part number is:
  • Potentiometer: ALPSALPINE RK09D1130C3C
This component is available from electronics suppliers such as Digikey, Mouser, or AliExpress.
If you have a RADR wireless remote, you can continue using your OSSM while waiting for the replacement. The RADR provides full speed and stroke control.

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Right encoder skips clicks or rotations

If the right encoder on the wired remote only registers every second or third click when navigating menus or adjusting parameters, the encoder component may be faulty.
Symptoms:
  • Remote display turns on and shows the menu
  • Left knob (speed control) works normally
  • Right encoder responds inconsistently—only some clicks or rotations are registered
  • Turning the encoder requires multiple clicks to move through menu items
  • Solder joints on the remote board appear intact
Diagnosis:
  1. Power on OSSM and navigate to any menu
  2. Slowly turn the right encoder one click at a time
  3. Count how many physical clicks it takes to move one menu position
  4. If it consistently takes 2–3 clicks to register a single movement, the encoder is defective
Before concluding the encoder is faulty:
  1. Power off and reseat the RJ45 cable at both ends until it clicks
  2. Try a different RJ45 cable if available
  3. Inspect the cable connectors for bent pins or debris
  4. Power on and test again
If the issue persists after checking the cable, the encoder itself is defective.
A partially responsive encoder indicates a hardware fault that cannot be fixed through software or settings. Some batches of encoder components have been found to have this defect. Contact support to request a replacement wired remote under warranty.Self-repair option: If your remote is out of warranty or you prefer to repair it yourself, the encoder part number is:
  • Encoder: ALPSALPINE EC11E18244AU
This component is available from electronics suppliers such as Digikey, Mouser, or AliExpress.
If you have a RADR wireless remote, you can continue using your OSSM while waiting for the replacement. The RADR provides full control without relying on a wired connection.

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Boot loops or display artifacts

If your OSSM repeatedly restarts (boot loops) or shows corrupted characters, flickering, or visual glitches on the wired remote display, there may be a hardware fault with the wired remote board or the main control board.
Symptoms:
  • Device restarts repeatedly without completing the homing sequence
  • Display shows garbled text, flickering, or visual artifacts
  • Crashes or reboots occur when using the right knob (encoder)
  • Random, uninstructed changes to speed, depth, or stroke parameters
  • Motor attempts to exceed position limits (violent movement, belt skipping)
  • Problems persist after trying different firmware versions
What to rule out first: Before suspecting a hardware fault, try:
  1. Different RJ45 cable — A damaged cable can cause intermittent faults
  2. Different power supply — Voltage fluctuations can cause instability (use a UL-listed 24V supply rated for at least 5A)
  3. Reflash firmware — Corrupted firmware can cause unexpected behavior. Use the Web Flasher to install the latest stable version.
If basic troubleshooting doesn’t help, verify the control board is receiving power correctly:
  1. Check the 3.3V LED — The control board has a small blue LED near the ESP32 chip. If this LED is on, the board is receiving power and the voltage regulator is working.
  2. Check 24V at the input terminals — Use a multimeter to verify 24V DC at the power input terminals on the control board. You should read between 23V and 25V.
  3. Check voltage at motor terminals — Measure voltage at the motor output terminals to confirm power is reaching the motor driver.
If the 3.3V LED is off or dim, or if voltage readings are incorrect, the issue may be with your power supply or the control board itself.
Isolate whether the wired remote is causing the issue:
  1. Power off the OSSM completely
  2. Disconnect the wired remote’s RJ45 cable from the control board
  3. Power on the OSSM
  4. Observe the serial output via USB (optional) or listen for motor movement
Interpreting results:
  • If the OSSM boots normally and homes without the remote connected, the wired remote board is likely faulty.
  • If the OSSM still fails to boot or crashes without the remote connected, the main control board may be faulty.
If you have a RADR wireless remote, connect via RADR after disconnecting the wired remote to test normal operation.
Boot loops, display corruption, or erratic parameter changes that persist after troubleshooting indicate a hardware fault. Depending on test results:
  • Wired remote at fault — Contact support to request a replacement wired remote board under warranty.
  • Control board at fault — Contact support to request a replacement control board under warranty.
While waiting for a replacement, you can continue using your OSSM with a RADR wireless remote if you have one available (assuming the main control board is functional).

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Reset button and flashing firmware

The OSSM control board has a small reset button near the blue LED. Understanding what this button does—and what it does not do—can help avoid confusion when troubleshooting or updating firmware.
The reset button on the OSSM control board performs a power cycle reset. Pressing it restarts the ESP32 microcontroller, similar to unplugging and reconnecting power.What it does:
  • Restarts the ESP32 and reinitializes the firmware
  • Clears any temporary runtime state
  • Can help recover from a frozen or unresponsive state
What it does not do:
  • It does not erase stored settings or calibration data
  • It does not wipe the flash memory
  • It does not perform a factory reset or clear WiFi credentials
  • It does not trigger a new homing sequence automatically (homing occurs on boot as part of normal startup)
If your OSSM becomes unresponsive, try pressing the reset button once. You do not need to hold it down—a single press is sufficient.
The standard OSSM firmware does not include a built-in factory reset function. To completely clear settings and return to defaults:
  1. Reflash the firmware using the Web Flasher. This overwrites the existing firmware but may not clear all stored data in flash memory.
  2. For a complete flash wipe, you need to use development tools like PlatformIO or esptool to erase the flash before reflashing. See PlatformIO setup for details.
Most users do not need to perform a full flash wipe. Standard reflashing via the Web Flasher is sufficient for firmware updates and resolving most issues.
Some community members develop alternative firmware for specialized use cases. If you want to install community firmware:
Community firmware is not officially supported by Research and Desire. Use at your own risk. Some community projects may be experimental or deprecated.
Before installing community firmware:
  • Back up any settings you want to preserve
  • Note your current firmware version in case you need to revert
  • Read the community project’s documentation carefully
If the community firmware requires a clean flash: The reset button does not wipe flash memory. To fully erase flash before installing community firmware, you typically need to:
  1. Use PlatformIO with the Erase Flash command
  2. Or use esptool.py erase_flash from the command line
Contact the community firmware developer (often via Discord) for specific installation instructions, as requirements vary between projects.
To return to official firmware after experimenting with community builds, use the Web Flasher to reinstall the latest stable release.

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Still having issues?

If you’ve worked through these troubleshooting steps and still have problems:

Report an issue

Found a bug or design problem? Submit a detailed issue on GitHub.
 Get real-time help from experienced builders on Discord: