u/Specialist_Web_2565

My RC car only drives in reverse. When I press forward, the motor doesn't receive any voltage, but it does when I press reverse.
I opened the controller board, checked the circuit with a multimeter, watched a few basic troubleshooting tutorials, and suspected the S8050/C8050 transistors. I replaced the suspected transistors (two C8050 and two S8050), but the problem is exactly the same.
What else should I check? Could it be another transistor, a damaged diode, a bad trace, the receiver IC, or something else in the H-bridge circuit?
I'm attaching photos of the PCB (both sides). Any help identifying the fault or suggesting measurements to take would be appreciated.