Yes, since the start of this thread all ISA cards have been removed and the mismatched memory pair also removed, leaving a single matching pair in bank zero.

I might have to shelf this until the weekend for now. I do have a PCI to IDE expansion card coming anyway, so I'm hoping that will give some closure on this and at least rule out certain failure options. But the bigger and worse news, hence the shelving, is that I've somehow managed to cause a (almost) dead short between CLOCK and GND of the keyboard PS/2 port. I guess with all the fiddling I've been doing, something maybe shorted it at some point and that damaged something. At the weekend I plan to trace the traces as my hope is that it's a passive component, like a cap, between CLOCK and GND that can be replaced/removed, but I don't have the time for that right now. The mouse PS/2 port does not show any short issues so I'm certain it's something I've done.

Thank you to all your help so far, and I'll keep this thread updated with anything later in week.

Doh! Sometimes you dig out an old machine that hasn't been touched for years and it does work for that one final time and then never nicely again. It has happened to me a few times now.

Best of luck with it!!

I noticed there is an eBay seller with a bunch of Packard Bell stuff that appears to be located near where Packard Bell was headquartered, so if all else fails, maybe you can get a replacement motherboard. Because they are LPX, the appeal is limited to others without the matching case and riser card. However, I wonder if something is out-of-whack with your power supply given all the problems you are having and their sudden onset.

DexterHill0 wrote on 2026-07-27, 13:45:

Honestly that explanation to me makes a lot of sense. If the original reset killed the IDE controller while it was doing something with the HDD, perhaps that corrupted it too. For some reason right now it is no longer picking up my keyboard butonce it recognises it again I will try disable the first (primary) IDE slot to see if I can force it into using the secondary slot.

Also, both cables show the same symptoms so I don't think the cables are bad

Sounds like primary IDE is in trouble and it's not your drive and cables.

A fix could be complicated, but if you just have one HDD and one CDRom drive, a simple workaround would be to just use both on the secondary controller, so HDD as master and CDRom as slave. You don't want to try recording CDRWs like that, but for retro use it should be fine.

Quick update,

It's mostly bad news. The keyboard not working ended up being the Super I/O chip itself, not the capacitor I originally though (and hoped) it would be. It's got a short to ground inside of it, even after I fully removed it from the motherboard. I'm stubborn, so instead of calling it quits I've ordered a new and will do my best to try and solder it back on.

Until then I can't really test anything in the BIOS as I have no working keyboard. I did receive the PCI to IDE adapter but, again, without being able to get into the BIOS to fiddle with settings, it hasn't changed anything yet.

I doubt I will be replacing the chip until the end of August since I'm away most likely when it will arrive, but I will update again on the outcome of that. Thank you again to everyone who has attempted to help so far.

DexterHill0 wrote on 2026-08-04, 13:18:

Quick update,

It's mostly bad news. The keyboard not working ended up being the Super I/O chip ...

Bummer,

Hopefully you'd never have to replace it again (but it did fail once), probably worth putting in a socket.
No only would it make it so much easier if you ever have to replace it again (or the new one doesn't work), it's something you can do now, and just pop in the chip when it comes.

DaveDDS wrote on 2026-08-04, 13:41:

Bummer,

Hopefully you'd never have to replace it again (but it did fail once), probably worth putting in a socket.
No only would it make it so much easier if you ever have to replace it again (or the new one doesn't work), it's something you can do now, and just pop in the chip when it comes.

That's a great idea but I think finding a socket to fit this chips footprint will be quite hard. A brief search for one doesn't return anything useful (most are expensive breakout boards rather than just bare sockets). I'll do a little more digging at the weekend though

I still think you should consider whether the power supply might be frying things given all the issues

jakethompson1 wrote on 2026-08-04, 18:49:

I still think you should consider whether the power supply might be frying things given all the issues

That's a fair point, although I'm not sure how I'd test it now since I don't have the mobo working to give it a load. As I mentioned originally, the caps all look okay but obviously that doesn't mean they are okay internally. Would you suggest just replacing all caps in it anyway then?

Didn't forget about this!!

A fair few things have changed - in hindsight, maybe too many in one go but I was trying to make the best use of my time - but sadly I'm no further forward than I was before...

The first thing I did was replace the Super I/O chip as I confirmed that was dead. After replacing it, I found out that the person that gave me the computer originally did actually have a PS/2 keyboard, so I decided to wait to turn it on until I got that keyboard to rule out my RPI hack job as a possibility for being the cause of the issue.

While I was waiting to get the keyboard, I also found a listing for 2x of the southbridge 82371FB chip, so I bought them and decided to also replace that chip on my motherboard, given the possible PRI IDE channel failure. It went well, compared to the first time, and multiple visual inspections with magnification didn't expose any solder bridges. I then, to rule out transient voltage issues, recapped the power supply and the two electrolytic caps by the VRMs.

Eventually I got the keyboard (Sunday), and tried to turn the PC. Thankfully nothing catastrophic occurred, but it wouldn't even POST at first. After another visual inspection I did find a couple solder bridges on the southbridge chip (I've no idea if I missed them the first time or if somehow maybe I caught the chip while doing the recap ¯\_(ツ)_/¯) but after fixing them it did POST. Sadly, it got no further than before, reporting not only a floppy controller error but still failing to find any bootable media. I've got a couple things I'm going to try over the next few days, worst case even replacing the chip a second time, because perhaps the shorts caused the issue, but if that proves fruitless then I think I will have to consider that a defeat.

With all this fiddling I've done it really could be anything, maybe I've damaged the northbridge, some other component, IDK, and without a datasheet of the motherboard though I think I'm really at a disadvantage. If anyone has any ideas since it can at least POST now then let me know (P.S. the HDD isn't detected in either the PRI or SEC slot).

Got to love the hours we sink into these things sometimes! If this was mine I'd next try a PCI ide controller card or even a SCSI card and drive for more fun. So hard to give up after all the effort.