PS2 couplers stopped firing

GGG can fix it (and others here)

GGG | O Gauge Railroading On Line Forum (ogaugerr.com)

Q1 and Q2 on the processor board are the coupler FETs, they an FDN5630 MOSFET.

Do you have lights and smoke heat?  If not, you fried the PV line.  There is a work around, but it is a one time fix.  The cause of the failure must be found.

Lights and smoke still work. Well, one is a RK diesel without smoke feature, but the other still chugs away happily with smoke, headlights, reverse lights, number board and cab lights.

@gunrunnerjohn when I have a chance I'll check all the way back to the pins for what resistance is going through the coil to make sure it's not broken or shorted, but after that I don't think I'm equipped to do component level fixes that small.

Maybe it's time to just bite the bullet and get a bunch of PS3 upgrade kits now. Normally I wouldnt worry too much, but we use the couplers all the time and it's really annoying.

AYMK, you have to be sure of why it failed before putting a new kit in it. It may just fail again.

Joe has a very valid point.

PV failure won't effect smoke heat as that has a direct jump wire on bottom of processor board.  You do lose lights and couplers.

If couplers gets bent they won't work.  Or wire breaks off coupler.  Take a good coupler and plug into harness and test to see if it fires.  If not wring out wire from connecter to 12 pin coupler pin.

If that is all good and it won't wire then chances are you did damage a coupler fet or worst.  G