Here is one for the brain trust.
I picked up a PL400 with the pl14 board.
It had a blown line fuse, and the rail fuses were fine.
I replaced the blown fuse and hooked up the DB tester and the Variac, the DBT lit up very bright, and there was no voltage to the meters or the filter caps.
I checked each output transistor, and all 4 tested fine.
I then took out the rail fuses, and fired it up again. The meter lights worked fine, and the Filter caps had good voltage (80+, variac wasnt all the way up) and the DBT did not light up.
I then put the Left rail fuse in, meters lit up, filter caps charging. I then pulled that fuse and put the Right rail fuse in, and again, ights on, filter caps charging. Put both rail fuses back in, the DBt lit up and the filter caps were not charging.
So, any ideas were to check next?
Thanks for your time in this!