What exactly is the problem? Power on or booting?

ux-3 wrote on 2024-07-31, 20:24:

What exactly is the problem? Power on or booting?

The system will power on reliably when it is switched on. PSU fan will spin, power led illuminates and the keyboard lights flash on momentarily. The vast amount of the time it will not progress passed this point. After a number of on/off cycles the system will start up properly and boot/post.

So your system does not post. But if it posts, it boots?

I would use a hairdryer and blow warm air into the PSU. Will this increase your success rate?

I thought I was being pretty clear with what is going on.. I don't know how else to explain it. click, nothing, click, nothing. repeat x number of times, click boot

Post and boot are two different functions.
Post happens first and has to do with the hardware working correctly.
Then Boot happens this has to do with the Operating system ( DOS or Windows )

Trouble shooting computer hardware is a Process of Elimination.
Find out what hardware components work and which don’t.

Power off the computer. Unplug it from electrical outlet.
Disconnect the hard drive. We want to make sure it is posting correctly.
Plug it back in outlet
Power on.
If it displays the IBM splash screen hit the <esc> key to show the boot process.
Take a photo and upload the photo so we can see what is happening.

If the computer posts okay then it is working properly.

If it still will not post then disconnect the other drives one at a time until it posts okay.

If it still wont post okay then check your RAM.

Also check to see your PC Cards are set in slots properly.

You may have to also remove the cards one at a time to see if this fixes the problem.

Bad caps sometimes do that, bad solder joints or loose/damaged components can do that also.

Need to do a full diagnostic to see what is going on.

rmay635703 wrote on 2024-08-01, 03:33:

Bad caps sometimes do that, bad solder joints or loose/damaged components can do that also.

Need to do a full diagnostic to see what is going on.

I've recapped the entire board and inspected it under magnification for any bad solder joints.. I have found none. I've removed all cards, tried reseating the ram and proc, as well as moving the proc to different slots. Nothing seems to be making a difference. It will post with patience and a number of cycles. All I can think of left, as you said, is failing components.. proc and ram.. neither of which I can easily get

squee2001 wrote on 2024-08-01, 15:48:

rmay635703 wrote on 2024-08-01, 03:33:

Bad caps sometimes do that, bad solder joints or loose/damaged components can do that also.

Need to do a full diagnostic to see what is going on.

I've recapped the entire board and inspected it under magnification for any bad solder joints.. I have found none. I've removed all cards, tried reseating the ram and proc, as well as moving the proc to different slots. Nothing seems to be making a difference. It will post with patience and a number of cycles. All I can think of left, as you said, is failing components.. proc and ram.. neither of which I can easily get

Ment moving the ram.. not proc.. Coffee is still trying to take effect..🤣

Tried hot air?
Removed mouse and keyboard?

This era of IBM build does seem to be one of the worst for oxidation coating on all switches and sockets, and take a good work over with Isopropyl and contact cleaner to deglitch. Plus they will hate 98% of the RAM in a shoebox full, so yay that makes things easier.

tried alternative parts like ram, VGA?

I love that Splash screen. It’s so comforting does it have a boot chime ?

Intel486dx33 wrote on 2024-08-01, 20:02:

I love that Splash screen. It’s so comforting does it have a boot chime ?

Unfortunately not. I'm having a bit of a battle with the sound card drivers refusing to install off of anything but a floppy disk.. so I'm waiting for disks.

ux-3 wrote on 2024-08-01, 19:05:

tried alternative parts like ram, VGA?

VGA is on board and I unfortunately don't have any replacement ram sticks

ux-3 wrote on 2024-08-01, 17:51:

Tried hot air?
Removed mouse and keyboard?

Tried with no kb and mouse. Have not tried hot air. I'm curious what that is supposed to do?

BitWrangler wrote on 2024-08-01, 19:00:

This era of IBM build does seem to be one of the worst for oxidation coating on all switches and sockets, and take a good work over with Isopropyl and contact cleaner to deglitch. Plus they will hate 98% of the RAM in a shoebox full, so yay that makes things easier.

I have to put new thermal tape on the proc anyways so ill pull it and the ram and hit everything with iso

squee2001 wrote on 2024-08-01, 20:08:

Tried with no kb and mouse. Have not tried hot air. I'm curious what that is supposed to do?

Shortens warm up of components. If it works then, you know that the cold components give you the issues. Often CAPS in PSU.

ux-3 wrote on 2024-08-01, 20:49:

squee2001 wrote on 2024-08-01, 20:08:

Tried with no kb and mouse. Have not tried hot air. I'm curious what that is supposed to do?

Shortens warm up of components. If it works then, you know that the cold components give you the issues. Often CAPS in PSU.

Ah I see ok. I did replace the PSU.. the one that was on it was dead dead

squee2001 wrote on 2024-08-01, 20:57:

ux-3 wrote on 2024-08-01, 20:49:

squee2001 wrote on 2024-08-01, 20:08:

Tried with no kb and mouse. Have not tried hot air. I'm curious what that is supposed to do?

Shortens warm up of components. If it works then, you know that the cold components give you the issues. Often CAPS in PSU.

Ah I see ok. I did replace the PSU.. the one that was on it was dead dead

I have a hot air rework station.. should work well for that task