I got the same combo a few months ago, with I think about the same symptoms. The fix was to replace several Ta caps on the top-most board (controller, I think). It's easy to check the power supplies on jumpers and chokes near the right front area. There are maybe ten or so epoxy-molded axial Ta caps sprinkled around the board, mostly toward the back. I found two or three bad, and replaced all with hermetically sealed type Ta ones I had in stock. This cleared the shorts on the supplies, and it came right up and worked just fine.
Just keep checking all the supplies, and lifting any Ta caps found until you get the right one(s). Some were hard to spot at first. There are others in the instrument, but these were the culprits in this case, and fortunately the most accessible of all. I had unplugged the various boards from each other until I had it isolated to this one, before looking at the details.
I studied up on the 2402A, and decided it was not worth keeping, so junked it out.
Ed
