I've finally gotten one of my PDP-8/Ls back on its feet - the solution: remove *all* the cards, hose down the backplane with contact cleaner and clean each and every finger of each and every card. The hit-and-miss stuff just wasn't cutting it, nor was alcohol. I don't know what's in the contact cleaner, but I have a small case of it I aquired from a now-defunct Commodore Dealer here in town (there are *no* ingredients on the label, nor any references to MSDS sheets, so it must be old). As a bonus, I set up a tripod and an 8mm camcorder and took 1 second shots between each card insertion. I now have a 1.75 minute time-lapse movie of the cards popping in, one by one. What I _don't_ have is a way to digitize the movie. :-( When all was done, I fired up the machine and it ran the following program the first time: 0020 7604 LSW / Clear accumulator and OR in the Switch REgister 0021 5020 JMP 0020 / Do it again Core is fine, power fail/restart is fine, all the front panel switches appear to be fine. This machine hasn't worked right for *years*. A good stiff cleaning is all it took. Now, on to TTY tests and eventually, MAINDECs. One gotcha with this box - one of the fuse holders is loose at the back of the PSU. In its untightened state, it produces an open circuit if I move the box around and don't wiggle it back to its groove. I may need to remove most of the cards to remove the PSU to get to the nut. <sigh>. One down, two to go. -ethan ===== Infinet has been sold. The domain is going away in February. Please send all replies to erd(a)iname.com __________________________________________________ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one place. Yahoo! Shopping: http://shopping.yahoo.com