Breadfan
New Member
I picked up a non-running Compaq Deskpro 286e some years back and never messed with it much - at the time I just knew it wouldn't boot, probably a faulty PSU.
I've started to dig into it, and want to troubleshoot it properly due to it's age.
I believe something in the PSU may be shorting causing it to go into overload mode. The reason I believe this is that I remember years ago tossing power to the computer and switching it on - the fan would spin for a half second and stop, and then repeat every few seconds.
Now that I'm digging into it and have gone further into reviving old gear, I better know the risks on vintage gear so am trying to bench test the PSU. Using my digital multimeter I can see on several pins (disconnected from the board) that it will spike voltage to briefly read "OL" on the auto range multimeter on DCV. Same cadence as I recall the fan would spin.
The issue is, to really dig into this, I have no idea what the pinout is, and no doubt Compaq didn't have a standard AT pinout.
Looking inside the PSU and on the motherboard, there are no printed pinouts, and...all the wires are white :D
Anyone have thoughts, ideas, or a pinout for one of these? Or possibly an idea on a common failure point with these? I've not started a deep dive in the PSU, just a cursory visual inspection that yields no obvious failed caps or burned parts. Most likely it will require some circuit tracing to find a fault.
I've started to dig into it, and want to troubleshoot it properly due to it's age.
I believe something in the PSU may be shorting causing it to go into overload mode. The reason I believe this is that I remember years ago tossing power to the computer and switching it on - the fan would spin for a half second and stop, and then repeat every few seconds.
Now that I'm digging into it and have gone further into reviving old gear, I better know the risks on vintage gear so am trying to bench test the PSU. Using my digital multimeter I can see on several pins (disconnected from the board) that it will spike voltage to briefly read "OL" on the auto range multimeter on DCV. Same cadence as I recall the fan would spin.
The issue is, to really dig into this, I have no idea what the pinout is, and no doubt Compaq didn't have a standard AT pinout.
Looking inside the PSU and on the motherboard, there are no printed pinouts, and...all the wires are white :D
Anyone have thoughts, ideas, or a pinout for one of these? Or possibly an idea on a common failure point with these? I've not started a deep dive in the PSU, just a cursory visual inspection that yields no obvious failed caps or burned parts. Most likely it will require some circuit tracing to find a fault.