Troubleshooting on mBot

1. mBot motor shaft(s) broke, what do I do?

You may find two spare motor shafts in the mBot package, and refer to the video tutorial to replace the broken one(s). In case you do not have these for any reason, contact us at


2. mBot moves in an opposite direction as the given instruction from IR remote controller, why?

  1. The wires of the motors may be connected reversed. Please have a check.

  2. Change the battery for mBot since mBot may not function normal when no enough power provided.

According to our test and research, it is suggested to use rechargeable Li-ion battery or rechargeable nickel-metal hydride, nickel-cadmium which can be bought from amazon or local shop. Or Alkaline battery with good quality like Energizer, DURACELL.

3. mBot fails to connect to Makeblock App via Bluetooth, why?

a. Check if your mBot is the version with a 2.4G module instead of a bluetooth module.

     You may have purchased the 2.4G version mBot with a 2.4G module which cannot be connected to the App. Replace the 2.4G module (left) with a Bluetooth module (right) can solve the problem. 


b. The battery power is too low.

     If the power is too low, the LED light of the bluetooth module will flash quickly. You can try the following methods to verify if the battery is too low: unplug the battery box connector, connect to the computer with a USB cable, and then connect to Bluetooth in the App (the computer's USB power supply is enough to power the Bluetooth module).

c. Interference from certain programs uploaded previously.

     You may have uploaded a program to the mBot. Try updating the firmware first and then connect again.

d. Damaged Bluetooth module.

Normally, the Bluetooth indicator flashes blue slowly after mBot is turned on, and turn to solid blue when Bluetooth connection is established. If the Bluetooth module indicator is solid blue and keeps remaining so after mBot is powered on, the Bluetooth module may be damaged. 


  1. We can also try to reset default program and upgrade firmware with USB cable connection on the mBlock 5 PC client first, and then connect mBot to the Makeblock app through Bluetooth.

  2. If no Bluetooth signal is detected, enable GPS on your device.

4. Why doesn't mBot move when motor speed is set as 50?

When we set the speed to 50, here the "50" is not the real speed value. The real running speed depends on the voltage and speed value.

Here we take mBot as an example:

  • The setting speed is 50, and the maximum speed is 255.

  • The battery is 3.7V, and it is fully charged.

  • The rated voltage is 6V forTT Geared Motor, and the no load speed: 200RPM±10.


Thus, setting speed to 50 might be too slow for TT Geared Motors to run. Try 100 above to have a look.

5. Why does mBot's infrared remote control not work? 

Under the factory setting mode, if the infrared remote control fails to control mBot, you can check it in the following step:

a. The romote control has no battery or battery installed backward.

Open the shell on the back of the remote control and check whether the battery is installed correctly as the image below shows.

b. The battery has run down.

Replace with a new CR2025 battery and try again.

c. The remote control no infrared signal output.

Check the remote control for signal output and turn on the phone's camera (iOS system is not supported, please test with Android ). After truning on the phone's camera, aligning the remote control and press a botton at random. If the remote control has red light, the remote control is not broken.

d. Infrared receiver on the mainboard dropped or lost.

Under this circumstance, please contact the vendor to replace or repair.

6. How to determine if a mCore motherboard is malfunctioning or not?

To determine if a mCore motherboard is malfunctioning or not, we can upload a simple program with Arduino IDE and check the result.

Step 1: Download Arduino IDE.

For Windows:

For macOS:

Step 2: Establish the USB connection.

Connect the mCore motherboard to your computer with the original USB cable and switch it on.

Click Tools>Board"...">Arduino Uno

Select the correct Port.


Step 3: Upload Program Blink

Click File>Example>01.Basics>Blink


Click Upload, wait and check if any error message pops up in red.


If no and the mCore is as below gif shows, then the motherboard should be functioning normally.


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