Dead extruder stepper on my ender 3 pro.

[AutoWiz]

Are your steppers running in standalone mode? And if so did you adjust the pot on the stepper and set the forward current to a happy place? It sounds like the vref might be a bit low. Or there might be a problem with the wires from the driver to the stepper or their connections. Also cable management is not a hard thing to get a hold of. Sometimes it means identifying and hunting down the right connector or pigtail. A lot of times it means using a soldering iron and making custom length harnesses. And it is always better if you design the mainboard tray with cable management in mind. My SKR PRO here has a stepper in every socket and yet not a single wire draped over the mainboard..

[Azurl]

Are your steppers running in standalone mode? And if so did you adjust the pot on the stepper and set the forward current to a happy place? It sounds like the vref might be a bit low. Or there might be a problem with the wires from the driver to the stepper or their connections. Also cable management is not a hard thing to get a hold of. Sometimes it means identifying and hunting down the right connector or pigtail. A lot of times it means using a soldering iron and making custom length harnesses. And it is always better if you design the mainboard tray with cable management in mind. My SKR PRO here has a stepper in every socket and yet not a single wire draped over the mainboard..

That is really beautiful cable management. I've been considering getting ribbon cables that I can cut to length and replacing the stock ones. but that's a later project, I tried increasing the forward current with no effect, then I increased the vref from 0.960 volt to 1.1 volt. no effect either, but these values have not been changed for over a year of operation, and it stopped working after I replaced the heatsink on the stepper controller, it was working without the heatsink, but stalled after a few minutes of operation. now I've tried 3 different stepper motors and 2 different stepper controllers. when I try to load or unload filament to make the extruder stepper move, it makes that jerk sound, in some cases I can try several times, but eventually it stops responding at all, and a led on the mainboard starts flashing really fast, it's the LED next to the Q3 transistor. can the mainboard have been damaged when I fiddled with the stepper controller?

Edit: I think they are in standalone mode, I didn't fiddle with any particular mode settings, unless I have it wrong it's either standalone or closed loop? I think they are in SPI mode.