Sometimes the EEPROMS give up...

You can definitely fix this with an EEPROM programmer. I don't know about current models but I have a TL-866II Plus, it payed itself many times over.

Maybe you will need another EEPROM in case yours is permanently damaged.

If you want there would be a trick that could start the Recovery BIOS, basically you have to prepare a floppy with the correct BIOS, and then put the disk and start the PC, if you can use a VGA ISA, in theory in a minute or a little more, it should finish restoring the BIOS, except that the BIOS chip is gone.

tauro wrote on 2025-01-10, 23:17:

Sometimes the EEPROMS give up...

You can definitely fix this with an EEPROM programmer. I don't know about current models but I have a TL-866II Plus, it payed itself many times over.

Maybe you will need another EEPROM in case yours is permanently damaged.

Looks like this might be it

https://www.amazon.com/TL866-3G-Programmer-Su … 131&sr=8-1&th=1

or

https://www.aliexpress.us/item/22518327825048 … ayAdapt=glo2usa

Where could I get a replacement EPROM? Ebay?

It looks like its called
AWARD SOFTWARE PCI/PNP 686 MOTHERBOARD BIOS 1998

I might need to take the sticker off to see the exact model. Thanks again for the reply. I think Ill try to source a EPROM before I get a reprogramer. Maybe Ill just get another board and swap the eprom over. It wouldn't be a bad thing to have one as a spare. Amazing board

PC@LIVE wrote on 2025-01-10, 23:23:

If you want there would be a trick that could start the Recovery BIOS, basically you have to prepare a floppy with the correct BIOS, and then put the disk and start the PC, if you can use a VGA ISA, in theory in a minute or a little more, it should finish restoring the BIOS, except that the BIOS chip is gone.

I didnt even know you could do this. I will need to research this. I did dump the original BIOS before I flashed it.

The BIOS has the following information

On the sticker it reads
AWARD SOFTWARE PCI/PNP 686 MOTHERBOARD BIOS 1998

Under the sticker on the top of the chip

SST 29EE020 150-4C-PH 963733-A

And on the back of the chip

SSTGP10 6083017 65440K

Looking at all my boards my test bench has one, and I have a dead motherboard with one also I may be able to use. So I might just need the reprogrammer. Still researching. Thanks for all the input so far.

k9cj5 wrote on 2025-01-11, 00:04:

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Looks like this might be it

https://www.amazon.com/TL866-3G-Programmer-Su … 131&sr=8-1&th=1

or

https://www.aliexpress.us/item/22518327825048 … ayAdapt=glo2usa

Yes, that's the TL866v2. Great piece of kit that's almost mandatory if messing around with vintage computers. Aside from flashing ROMs it can also test SRAM (cache) chips and even 74-logic ICs, which is useful if building replica cards.

Where could I get a replacement EPROM? Ebay?

Not a great idea, that will most likely give you another >25 year old chip (possibly re-marked to look newer) that might be about to die just like the one you already have. Same goes for the ones on AliExpress: patently obviously re-marked.

Better idea is from a reputable electronics supplier - although it can be a challenge to find new DIP EEPROMs like this. If you can't you might as well cannibalize old PCBs - that's where the eBay sellers' stock comes from anyway.

It looks like its called
AWARD SOFTWARE PCI/PNP 686 MOTHERBOARD BIOS 1998

I might need to take the sticker off to see the exact model.

Yep, the sticker is just generic.

The EEPROM is a 2Mbit (256kB) model, probably from Winbond. Take the sticker off to find the model. Then look up its specs (datasheet). Compare that to the 2Mbit EEPROMs you can find. So long as pinout, voltage and page size are the same, it should work.

k9cj5 wrote on 2025-01-11, 01:12:

The BIOS has the following information […]
Show full quote

The BIOS has the following information

On the sticker it reads
AWARD SOFTWARE PCI/PNP 686 MOTHERBOARD BIOS 1998

Under the sticker on the top of the chip

SST 29EE020 150-4C-PH 963733-A

And on the back of the chip

SSTGP10 6083017 65440K

Looking at all my boards my test bench has one, and I have a dead motherboard with one also I may be able to use. So I might just need the reprogrammer. Still researching. Thanks for all the input so far.

Right - SST29EE020 😀
Datasheet
Relevant specs:
256k x 8 organization page mode EEPROM
128 Bytes per page, 2048 pages
5-volt only operation
32-pin PDIP package

Basically you can assume most any 32-pin 2Mbit 29-series EEPROM (eg. Winbond 29C020) will be the same - but check to be sure. In particular, 28 and 27-series EEPROMs that seem to be common on eBay don't work with page mode and need 12V erase voltage. They won't work.

dionb wrote on 2025-01-11, 01:43:

Right - SST29EE020 :) Datasheet Relevant specs: 256k x 8 organization page mode EEPROM 128 Bytes per page, 2048 pages 5-volt onl […]
Show full quote

k9cj5 wrote on 2025-01-11, 01:12:

Under the sticker on the top of the chip
SST 29EE020 150-4C-PH 963733-A

Right - SST29EE020 😀
Datasheet
Relevant specs:
256k x 8 organization page mode EEPROM
128 Bytes per page, 2048 pages
5-volt only operation
32-pin PDIP package

Basically you can assume most any 32-pin 2Mbit 29-series EEPROM (eg. Winbond 29C020) will be the same - but check to be sure. In particular, 28 and 27-series EEPROMs that seem to be common on eBay don't work with page mode and need 12V erase voltage. They won't work.

Agree. My one P2B-F has an Atmel 49F002NT eeprom (it is the original), my other P2B-F does have a 29C020. So there are other bios that Asus does support on this board but they are specific page or specific block mode 5v only types as you said.

Worth trying
https://www.bios-mods.com/forum/showthread.php?tid=316

Worth noting to remember to hit enter on the last line of the bat file

k9cj5 wrote on 2025-01-11, 00:05:

PC@LIVE wrote on 2025-01-10, 23:23:

If you want there would be a trick that could start the Recovery BIOS, basically you have to prepare a floppy with the correct BIOS, and then put the disk and start the PC, if you can use a VGA ISA, in theory in a minute or a little more, it should finish restoring the BIOS, except that the BIOS chip is gone.

I didnt even know you could do this. I will need to research this. I did dump the original BIOS before I flashed it.

The topic is visible on YouTube, in one of the many videos of "BuB", I took some images that I hope can help you, but as I said you need a VGA ISA a floppy drive 💾 it's a 1.44MB disk in excellent condition, then of course the BIOS to write, here you have to be sure that it is right, because there are various versions of the cards, if you have a copy of the original one, I would say it's fine 😌, otherwise you can go to the retroweb site, there are also various versions of BIOS more or less updated.
This process, I used it a few times, the trick simply forces the reading from the floppy, something that your motherboard could already do, but without VGA ISA you will not see anything on video, here I suggest you try it only in case you are not looking for the floppy, but I think it already does, at least for me it was like that, the trick works on cards without any sign of life for the most.