Have you tried a simple PCI video card (like older S3 Trio, etc) and does it work ? Knowing if the PCI works at all will help figure out what chip is borked.
The 82441 north bridge supplies the PCI signals and the south bridge 82371SB supplies the PCI to ISA bridge and HD interface. edit The 82442 is host data bus stuff.

bypass bios, boot from floppy with mhdd
https://hddguru.com/software/2005.10.02-MHDD/ https://hddguru.com/software/2006.02.10-Magic-Boot-Disk/

Horun wrote on 2024-02-23, 22:40:

Have you tried a simple PCI video card (like older S3 Trio, etc) and does it work ? Knowing if the PCI works at all will help figure out what chip is borked.
The 82441 north bridge supplies the PCI signals and the south bridge 82371SB supplies the PCI to ISA bridge and HD interface. edit The 82442 is host data bus stuff.

PCI seems to work as does ISA. There is no onboard video so I did have a card plugged in. Also tried an ISA SCSI controller I had and it is detected. Seems just related to onboard IDE.
I'm kind of wondering if a cheap CF->IDE adapter might have been the cause.

rasz_pl wrote on 2024-02-23, 22:54:

bypass bios, boot from floppy with mhdd
https://hddguru.com/software/2005.10.02-MHDD/ https://hddguru.com/software/2006.02.10-Magic-Boot-Disk/

It's not a bios problem, it cannot communicate with drives correctly. I used an old working drive <512MB that boots into DOS successfully on another system.

I recommend reflashing the bios.

I have the same board as you (a Dell version running with a power adapter). It did not post until I did the flash recovery (via the jumper). Since then it’s been running flawlessly.

I also have the 450KX motherboard that mostly worked, but would occasionally not post or would hang in the OS. Reflashing this board and it too now runs flawlessly.

The issue is the flash bios uses an early type of flash (like a usb mem stick) thus gets forgetful after 25 years. Both of my boards use the same intel flash chip (I suspect yours is the same as your board looks identical to my 440fx).

Reflashing refreshes the bios for another decade or two. Intel provided a bios recovery jumper anticipating flash degradation issues, from my guess.

The IDE goes through bios for all activity unless you are running something like NT (which doesn’t use bios), but even then, bios is required to bootstrap the OS. Thus if you have bit rot in the IDE parts of bios, you could easily have problems.

It’s sad to think of all the ppro motherboards that get junked or declared bad simply because Intel chose that kind of flash memory for bios and people don’t know about the need to reflash every few decades.

Some matrox video cards also have this issue, my “brand new” G400 refused to send a signal to my monitor until I reflashed it’s bios, due to the same issue (age resulting in flash memory loss)

Hoof wrote on 2024-02-24, 04:25:

I recommend reflashing the bios. […]
Show full quote

I recommend reflashing the bios.

I have the same board as you (a Dell version running with a power adapter). It did not post until I did the flash recovery (via the jumper). Since then it’s been running flawlessly.

I also have the 450KX motherboard that mostly worked, but would occasionally not post or would hang in the OS. Reflashing this board and it too now runs flawlessly.

The issue is the flash bios uses an early type of flash (like a usb mem stick) thus gets forgetful after 25 years. Both of my boards use the same intel flash chip (I suspect yours is the same as your board looks identical to my 440fx).

Reflashing refreshes the bios for another decade or two. Intel provided a bios recovery jumper anticipating flash degradation issues, from my guess.

The IDE goes through bios for all activity unless you are running something like NT (which doesn’t use bios), but even then, bios is required to bootstrap the OS. Thus if you have bit rot in the IDE parts of bios, you could easily have problems.

It’s sad to think of all the ppro motherboards that get junked or declared bad simply because Intel chose that kind of flash memory for bios and people don’t know about the need to reflash every few decades.

Some matrox video cards also have this issue, my “brand new” G400 refused to send a signal to my monitor until I reflashed it’s bios, due to the same issue (age resulting in flash memory loss)

This is not wrong. However it wont help the issue. Most bios firmwares have a built-in checksum. One of the very first things the BIOS firmware does is do a self-check against this checksum. any errors = no post. just as you described. But it is almost always a pass/fail situation. Having a bad bit(s) that corrupt the IDE function and do NOT result in a fail checksum are likely in the realm of winning the powerball. Twice.

its still a good idea to update to the latest bios, regardless.

I would do a very careful inspection of the board. specifically the tiny leads to the chipset. I would also look for any damage in general. I see a bunch of pull up/down resistor packs, connected directly to the IDE channels. Give this close attention as well. In my experience, losing IDE is a failure in the southbridge. But I like to kick IDE to the curb whenever I can and use SCSI/SATA. so its far from a death sentence.

luckybob wrote on 2024-02-24, 04:54:

This is not wrong. However it wont help the issue. Most bios firmwares have a built-in checksum. One of the very first things […]
Show full quote

Hoof wrote on 2024-02-24, 04:25:

I recommend reflashing the bios. […]
Show full quote

I recommend reflashing the bios.

I have the same board as you (a Dell version running with a power adapter). It did not post until I did the flash recovery (via the jumper). Since then it’s been running flawlessly.

I also have the 450KX motherboard that mostly worked, but would occasionally not post or would hang in the OS. Reflashing this board and it too now runs flawlessly.

The issue is the flash bios uses an early type of flash (like a usb mem stick) thus gets forgetful after 25 years. Both of my boards use the same intel flash chip (I suspect yours is the same as your board looks identical to my 440fx).

Reflashing refreshes the bios for another decade or two. Intel provided a bios recovery jumper anticipating flash degradation issues, from my guess.

The IDE goes through bios for all activity unless you are running something like NT (which doesn’t use bios), but even then, bios is required to bootstrap the OS. Thus if you have bit rot in the IDE parts of bios, you could easily have problems.

It’s sad to think of all the ppro motherboards that get junked or declared bad simply because Intel chose that kind of flash memory for bios and people don’t know about the need to reflash every few decades.

Some matrox video cards also have this issue, my “brand new” G400 refused to send a signal to my monitor until I reflashed it’s bios, due to the same issue (age resulting in flash memory loss)

This is not wrong. However it wont help the issue. Most bios firmwares have a built-in checksum. One of the very first things the BIOS firmware does is do a self-check against this checksum. any errors = no post. just as you described. But it is almost always a pass/fail situation. Having a bad bit(s) that corrupt the IDE function and do NOT result in a fail checksum are likely in the realm of winning the powerball. Twice.

its still a good idea to update to the latest bios, regardless.

I would do a very careful inspection of the board. specifically the tiny leads to the chipset. I would also look for any damage in general. I see a bunch of pull up/down resistor packs, connected directly to the IDE channels. Give this close attention as well. In my experience, losing IDE is a failure in the southbridge. But I like to kick IDE to the curb whenever I can and use SCSI/SATA. so its far from a death sentence.

I haven't checked for a bios but agree it doesn't seem to be the issue. I also have a good clock battery and it correctly retains time and settings.
I wish I had some SCSI drives then I would used them but also very expensive now. I mainly like the IDE because I'll run a CF adapter then I can pop it into my main PC quickly to move large files over.
I'd like it 100% working, though, as this seems to be a rarity with onboard sound. At least from what I've seen on eBay.

A cheap sata SSD is actually a bit easier, at least for me. On more than one occasion, i've bent pins on those little CF adapters when inserting the cards.

I do love SCSI. But with sata being so fast and cheap.... its a hard sale.

Onboard sound isnt the advantage it used to be. So many people making retro builds have very specific sound cards in mind, and end up disabling the onboard.

luckybob wrote on 2024-02-24, 14:38:

A cheap sata SSD is actually a bit easier, at least for me. On more than one occasion, i've bent pins on those little CF adapters when inserting the cards.

I do love SCSI. But with sata being so fast and cheap.... its a hard sale.

Onboard sound isnt the advantage it used to be. So many people making retro builds have very specific sound cards in mind, and end up disabling the onboard.

CF has been convenient to boot DOS with a few utilities/benchmarks and since the majority of older stuff I have doesn't have SATA onboard, its fastest. If I'm doing more than just bench testing I would possibly throw a card in or something different, i.e. SCSI.

I forgot to say I can't find any obvious damage on this board. Pins are all PERFECT on the bridge chips. I used one of those digital microscopes and nada. I have a thermal camera and don't see any obvious shorts either, nor extremely hot chips.

I would get out a good multimeter and test out those resistor packs. they look to be 330 ohms. any one of those being open or shorted would kneecap the IDE channels. and check all of the little resistors nearby. the IDE channels are pretty much directly connected to the chipset. so if the passive parts are good, your cable and drives are good... its likely to be a partially borked chipset at that point.

It would be potentially repairable, if you can find a donor part, but its beyond what I would personally fix. I would just disable the IDE in the bios and slap in a sata card. (if I hadn't already)

luckybob wrote on 2024-02-25, 16:33:

I would get out a good multimeter and test out those resistor packs. they look to be 330 ohms. any one of those being open or shorted would kneecap the IDE channels. and check all of the little resistors nearby. the IDE channels are pretty much directly connected to the chipset. so if the passive parts are good, your cable and drives are good... its likely to be a partially borked chipset at that point.

It would be potentially repairable, if you can find a donor part, but its beyond what I would personally fix. I would just disable the IDE in the bios and slap in a sata card. (if I hadn't already)

I'll give it a go. I'd be willing to try the chipset if I can find a donor board in my pile, I *think* i have a PII board that's destroyed that might have the same chipset.

I took the time to slap a PCI IDE card in I have laying around, and was able to load up Windows XP (heh). That was a pain as it DOESN'T boot from CD, so I had to find an old SCSI card and CDROM I have. Yes, I know, use SCSI. I don't yet have any hard drives unfortunately. I had a yellow exclamation in device manager about not having an IRQ but that was because I disabled the controller in BIOS, though I'm curious why it would show up at all, being disabled.

Everything else seems to work otherwise, though *something* is shorted as it powers on immediately when flipping the PSU switch.

I checked the 8 resistor networks below the IDE and they all ohmed out good at 33ohms. Dang. I was hoping for a simple fix.

Connect logic analyzer to IDE port, 8 data bits + control signals will suffice. This will tell you if its all dead or missing some signal.

I kinda fingered if Moz had that kind of equipment, they would likely know how to use it and would have done so already. hell, my equipment ends at a low end o-scope. Its also a moot point. the IDE comes straight out of the southbridge, minus the resistor networks. The number of things that can be wrong after you eliminate the easy stuff is pretty much only the chipset.

I'd disable the IDE in the bios, and slap in a SATA card (or SCSI or whatever). I dont feel the juice is worth the squeeze at this point.

luckybob wrote on 2024-03-02, 03:46:

I kinda fingered if Moz had that kind of equipment, they would likely know how to use it and would have done so already. hell, my equipment ends at a low end o-scope. Its also a moot point. the IDE comes straight out of the southbridge, minus the resistor networks. The number of things that can be wrong after you eliminate the easy stuff is pretty much only the chipset.

I'd disable the IDE in the bios, and slap in a SATA card (or SCSI or whatever). I dont feel the juice is worth the squeeze at this point.

It's still worth tracing things out IMO. I had a board with bad IDE one time and discovered the tiniest (only visible under microscope) little solder whisker between two pins of the header on the back of the board. Removed it and it worked fine. Only went back for a magnified visual because of what I saw on the scope.