OFFLIST (due to being placed on moderated mode) was Re: Problems with IBM 5150 Power

Assuming I read you correctly, the mobo appears to have problems. You should invest in a multimeter. 20$ or so from Radio Shack or even Walmart (probably in the automotive section). This way you can measure the voltages coming off the p/s pins accurately. Yes you sometimes need to "load down" a p/s to determine if it is functioning properly (in other words apply an actual resistance - the circuit it was meant to power or something equivalent. You can plug it into the mobo and test it by say pushing a paper clip into the back of the p/s connector for instance. Sounds like your mobo has issues. You want to start playing with old PCs and stuff - find some replacement mobos and whatnot. I'm too disorganized at the moment to even offer to provide one. Others in the group (MARCH) are bound to. Try Bill Degnan. But he's hours away... Besides swapping boards, try removing the socketed chips (CPU, etc.) and replacing just those. Or using that CPU in another computer or board. You have to have something else that runs an 8088 by now, don't you... Regards and best of luck. P.S - get a copy of "Inside the IBM PC", Peter Norton. Has to be PC-era. Has a picture of a mobo on the cover, but is very green. The earliest addition is not as useful as the slightly larger more commonly known one (i used to have the *newer* one, but have only the older, uglier, less useful addition now. Somewhere). It's a M-U-S-T if you're going to develop a basic understanding of what's going on under duh hood. You need to get a copy. --- On Mon, 7/27/09, Joe Giliberti <starbase89 at gmail.com> wrote: