I replaced a damaged motor to my first drone, GepRC Rocket Plus, and now the new motor and other working one on same side are not working.

Everything worked after soldering the new motor on (not the greatest solder with the cheap iron I got) and tested each motor successfully in Betaflight prior to re-assembly. Once assembled and armed for flight only 2 motors on the opposite side beeped accordingly and spun. The other 2 didn't function at all including the new motor. Made sure I wasn't in turtle mode and had the same results when switched to acro or angle modes. Checked motors on Betaflight after assembly and now the 2 motors do not spin when previously worked after repair. Not sure what I'm missing.

Other steps taken:

• BLHeli reads all 4 ESCs
  
• checked power output with multimeter and getting good results
  
• loaded my backup configuration in Betaflight
  

One thing I wonder is if the boot button on the controller was being pressed by any sandwiched wires when armed. Thought there was enough space, though.

Appreciate any help on this.

Check ur soldering.. get a jewelers loupe.. you may have accidentally bridged something … you will be amazed what u can’t see with the naked eye.
Also, why did the motor need replacing?

Motor was barely spinning after a crash. I checked the flight controller with BLHeli first which showed all 4 ESCs so I decided to replace the motor.

Thanks for the tip about the jewelers loupe. Will have to double check the solder joint.

I finally de-soldered my motor connection and re-soldered it this time with better soldering and magnification tools and made sure nothing was bridging. Still same problem. Only one side of the quad's motors run. Tried flashing the firmware again and still no change. Not sure if the flight controller got messed up somehow.

Currently have a GEP-F411-20A AIO on the GepRC Rocket Plus.  Can't seem to find any replacements in stock. Any suggestions for a different flight controller replacement if I have to go that route?

Thanks