Ralph, attached photo showing the Triacs. There are 4 of them. The triacs that came on the board are TECCOR Q4008L4 if my memory is correct. The bridge is a 8A 100V GBU802. The bridge ran hot enough that on later boards TAS moved it to the bottom of the board and attached it to the heat-sink. I think they also bumped it up to 10A. TAS sold a version of the SAW which was rated at 15A the only parts different were the triacs and the bridge. The triacs were TECCOR Q4015L5 might be L4 can't remember for sure. I don't have the number on the bridge but would assume it is a 15A ~20A 100V. This board was designed to be used in locos with 4 motors like an AA centipede or MTH F3AA with 4 motors. I have installed Q4015L5 triacs in a SAW and a 15A bridge and it seems to work correct on the bench but I have yet to install it in my centipede. A wild guess you could have one fried triac or one of the diodes in the bridge might be. Any 8-10A 100V bridge would work though unless you can find the exact triac that is on the board I would replace all four. Good luck, j
