Have CTC i3 Prusa clone and extruder motor stopped mid print. installed new right nozzle driver chip but no change. swapped X driver to extruder motor and got motion. Checked X motor using extruder driver and no motion. How to check board for fault that would require replacing board?

Can you add a picture of the drivers on your board? You might be able to simply change the broken one out.

tried to send two photos from my phone. don’t see my reply to you shown here on talk. hope pix came thru. sent earlier this morning.

MaddieG:
Did you receive the photos of my driver’s and my text?

I think you have already answered your question. If the X driver works for the extruder but the extruder driver doesn’t work for X then the driver is bad.

If the X driver works for both the extruder and for X then the other chips are bad. Simple process of elimination.