Sorry for my English as I do not know French. But the best information on these motor drivers seems to be on this forum. I need assistance with a G-Loc I am working on. The drivers seem to be working. On power on they will go to upper limit and back down, but. Motor don't hold position with weight in the chair. The fall and rest on bump stops. Motor test B will report left and right good. Motor test A where you can change speed will run for about a second and then stop.

I verified the 5v, 12v, & 15v based on info here. I also recapped the boards as I saw some other posts where strange issues were caused by failure of some of the smaller caps.
https://www.gamoover.net/Forums/index.php?topic=28660.0

Does this a driver board issue or something else in the cabinet