MAKCU Troubleshooting

Problem:

LED keeps blinking slowly and doesn't resolve

Possible Causes:

System stuck in configuration state, baud rate change didn't complete, or warning condition not clearing

What to Do:

Wait 10 seconds - some operations take time, unplug all cables for 10 seconds and reconnect, check for any error messages in device manager, or if the problem continues update to the latest firmware with MAKCU Toolkit (https://makcu.com/toolkit/)

Problem:

LED doesn't turn on or change state at all

Possible Causes:

LED hardware issue, firmware not running, or power issue

What to Do:

Verify device is powered (check USB connection), check if device is recognized in device manager, update the firmware with MAKCU Toolkit (https://makcu.com/toolkit/) (a chip with no MAKCU firmware, old V3 (AIO) or modified firmware: https://app.makcu.com/makcu/), or if still not working, there may be a hardware issue

Problem:

LED shows solid ON (green) but the mouse/controller doesn't work

Possible Causes:

Device driver issue on computer, USB port problem, or device compatibility issue

What to Do:

Update to the latest firmware with MAKCU Toolkit (https://makcu.com/toolkit/), check device manager for any error icons, try a different USB port, verify CH343 driver is installed correctly, check if COM port number is below 10, or try a different mouse/controller to test

Problem:

MAKCU is not changing baud rate or software is not connecting to MAKCU.

Symptoms:

• Software cannot communicate with MAKCU
• MAKCU not responding to commands
• Connection timeouts
• Device appears connected but no data exchange

Solution:

Open device manager and change the COM port to any number below 10 (you may force a COM port number if all are in use). Make sure MAKCU's baud rate matches what your software expects: MAKCU V4 runs at 4M baud by default; switch to 115200 only for software that needs it (see the steps below).

1. MAKCU V4 runs at 4M baud by default and remembers the setting. Only 4M and 115200 are available; 115200 is usually needed only by older software that expects it
2. To switch, hold the button on the USB1 side for about 1 second, then release (one change per hold). The LED on the USB1 side flashes once when it switches to 115200 and 4 times when it switches back to 4M; it does not flash the current rate at start-up
3. Change COM port in your software settings to match MAKCU's
4. Verify baud rate matches between MAKCU and your software
5. If you use the old AIO tool, set MAKCU to 115200

Problem:

Device Manager shows USB1 or USB3 connecting and disconnecting over and over.

Possible Causes:

The chip on that port has no firmware (the factory state of the ESP32-S3), damaged firmware, or the image meant for the other chip.

What to Do:

Use the migration page https://app.makcu.com/makcu/: connect one cable at a time, hold the button next to that port while plugging it in, and flash the matching chip on the page (USB1 first, then USB3). The loop stops once the button is held. When the board is recognised normally again, keep it up to date with MAKCU Toolkit (https://makcu.com/toolkit/).

Problem:

Holding the button down correctly and connecting the USB cable, but Device Manager is still boot looping.

Possible Causes:

MAKCU may be faulty, USB cables may be faulty, or your USB port may have issues supporting MAKCU.

What to Do:

Try another USB port, try another PC, try the other cable or replace the cable. If it still loops, open a ticket on Discord.