Whatever you have done to the bios image, it has messed up the bios checksum and now motherboard posts in bios recovery mode.
you need to make a bootable floppy and follow this guide : https://www.bios-mods.com/forum/Thread-Recove … ward-Bios-Flash

Tried, but the motherboard didn't even search for the floppy. The floppy's led drive turns on but there is no mechanical noises, and immediately says "drive A error"

Are you sure floppy is bootable? maybe try it in a working pc and see if it boots from it.

Karbist wrote on 2023-06-15, 14:44:

Are you sure floppy is bootable? maybe try it in a working pc and see if it boots from it.

Yes but the problem is the floppy doesn't even try to read the disc, i don't understand. I also tried different cables.

I've had similar experience with these "rescue" bootblocks. They just don't work properly - can't access the floppy (no drive activity at all), or read some tracks but hang anyway. There might not even be video output, just some weird beeps. I think that codepath is not very well tested - and it doesn't help that some of the BIOS images out there on the net are broken for some reason.

I remember I've managed to fix one such mobo by reprogramming the BIOS Flash chip in external programmer (it was a standard 32-pin DIP). The original BIOS (that I've backed up before even powering the mobo) was somehow corrupted and the first one I've found and tried was even worse. But I did find a working BIOS file eventually and the mobo finally booted properly.

it's possible to fix it without a programmer by swapping the bios chip in a working motherboard after booting in Uniflash but both chips must be 5v or 3.3v, you can't swap a 5v chip with 3.3v one or vice versa.

While I encourage people to try a bootblock flash in circumstances like this, I'm not sure if it has ever worked for me (if it did I don't remember, and I think I would). My routine was always to try that first, then when it failed to work I'd end up doing a hot swap flash. I finally bought a programmer so that I no longer have to engage in the risky business of hot swapping BIOS EEPROMs.

Deunan wrote on 2023-06-15, 16:53:

I've had similar experience with these "rescue" bootblocks. They just don't work properly - can't access the floppy (no drive activity at all), or read some tracks but hang anyway. There might not even be video output, just some weird beeps. I think that codepath is not very well tested - and it doesn't help that some of the BIOS images out there on the net are broken for some reason.

I remember I've managed to fix one such mobo by reprogramming the BIOS Flash chip in external programmer (it was a standard 32-pin DIP). The original BIOS (that I've backed up before even powering the mobo) was somehow corrupted and the first one I've found and tried was even worse. But I did find a working BIOS file eventually and the mobo finally booted properly.

Definitely, these embedded recovery mode does not work as intended! The floppy stays completely quiet, doesn't search for files at all.

Repo Man11 wrote on 2023-06-15, 18:20:

While I encourage people to try a bootblock flash in circumstances like this, I'm not sure if it has ever worked for me (if it did I don't remember, and I think I would). My routine was always to try that first, then when it failed to work I'd end up doing a hot swap flash. I finally bought a programmer so that I no longer have to engage in the risky business of hot swapping BIOS EEPROMs.

Can i buy this programmer and do that on my own ? I have 0 skills in such a things but i think should not be so difficult. I'm all ears.......would be a shame toss away this motherboard. I can't any "recovery bios" service nearby my region....eventually they would be not so cheap i bet

Sorry to remind this but ; always backup you proper original BIOS with a TL866 before any action like this..

So :
- buy a TL866
- buy a Windbond (or else) similar flashable eeprom chip
- get this (original Asus bios) https://www.grosfichiers.com/UPQgNTMufC4_u4Y3NefLGXA
- get Xgpro
- program the chip with the AWD file.
- and test

It's the only way I guess..
Just cross fingers that work but not fully 100% sure because of (maybe) specific HP stuff on the mainboard which would cause the manufacturer's standard BIOS.

80386SX wrote on 2023-06-16, 11:40:

Sorry to remind this but ; always backup you proper original BIOS with a TL866 before any action like this.. […]
Show full quote

Sorry to remind this but ; always backup you proper original BIOS with a TL866 before any action like this..

So :
- buy a TL866
- buy a Windbond (or else) similar flashable eeprom chip
- get this (original Asus bios) https://www.grosfichiers.com/UPQgNTMufC4_u4Y3NefLGXA
- get Xgpro
- program the chip with the AWD file.
- and test

It's the only way I guess..
Just cross fingers that work but not fully 100% sure because of (maybe) specific HP stuff on the mainboard which would cause the manufacturer's standard BIOS.

Thanks, that programmer costs 150 bucks! There are cheaper alternatives out there ? For example i found a programmer "Fasizi K150" and costs like 14 bucks

Anyway that's the BIOS chip, if can be helpful:

_StIwY_ wrote on 2023-06-16, 13:02:

Thanks, that programmer costs 150 bucks! There are cheaper alternatives out there ? For example i found a programmer "Fasizi K15 […]
Show full quote

80386SX wrote on 2023-06-16, 11:40:

Sorry to remind this but ; always backup you proper original BIOS with a TL866 before any action like this.. […]
Show full quote

Sorry to remind this but ; always backup you proper original BIOS with a TL866 before any action like this..

So :
- buy a TL866
- buy a Windbond (or else) similar flashable eeprom chip
- get this (original Asus bios) https://www.grosfichiers.com/UPQgNTMufC4_u4Y3NefLGXA
- get Xgpro
- program the chip with the AWD file.
- and test

It's the only way I guess..
Just cross fingers that work but not fully 100% sure because of (maybe) specific HP stuff on the mainboard which would cause the manufacturer's standard BIOS.

Thanks, that programmer costs 150 bucks! There are cheaper alternatives out there ? For example i found a programmer "Fasizi K150" and costs like 14 bucks

Anyway that's the BIOS chip, if can be helpful:

I doubt that anyone here will be able to vouch for the low cost alternative you've found. I bought my TL866 from an Amazon vendor for about $70.00 ( and they are still available from Amazon at that price here), but I don't know if that's true where you are.
There are vendors on Ebay who will ship a preprogrammed BIOS EEPROM for about the cost of that low dollar programmer you've found, and I think that would be a safer alternative than the low end programmer.

I contacted a private store which do reballing and such a things, even BIOS recovery. They asked me for 40 bucks, given that the BIOS found on internet work as intended. I think i'll accept the risk to toss away these money. No pain no gain?! I'll keep you updated.

_StIwY_ wrote on 2023-06-16, 13:02:

Thanks, that programmer costs 150 bucks! There are cheaper alternatives out there ? For example i found a programmer "Fasizi K15 […]
Show full quote

80386SX wrote on 2023-06-16, 11:40:

Sorry to remind this but ; always backup you proper original BIOS with a TL866 before any action like this.. […]
Show full quote

Sorry to remind this but ; always backup you proper original BIOS with a TL866 before any action like this..

So :
- buy a TL866
- buy a Windbond (or else) similar flashable eeprom chip
- get this (original Asus bios) https://www.grosfichiers.com/UPQgNTMufC4_u4Y3NefLGXA
- get Xgpro
- program the chip with the AWD file.
- and test

It's the only way I guess..
Just cross fingers that work but not fully 100% sure because of (maybe) specific HP stuff on the mainboard which would cause the manufacturer's standard BIOS.

Thanks, that programmer costs 150 bucks! There are cheaper alternatives out there ? For example i found a programmer "Fasizi K150" and costs like 14 bucks

Anyway that's the BIOS chip, if can be helpful:

The good point on your problem is that your AT29C020 is a reprogrammable chip model.
So you don't have to buy a new chip - just reflash the one you already have (dont forget to make a Verify CRC check then, to avoid any eeprom failure doubt).

_StIwY_ wrote on 2023-06-16, 16:20:

I contacted a private store which do reballing and such a things, even BIOS recovery. They asked me for 40 bucks, given that the BIOS found on internet work as intended. I think i'll accept the risk to toss away these money. No pain no gain?! I'll keep you updated.

A programmer costs you 50$. If you are in the retro world you'll gonna need it again and again.
Worthy investment.

_StIwY_ wrote on 2023-06-16, 13:02:

Thanks, that programmer costs 150 bucks! There are cheaper alternatives out there ? For example i found a programmer "Fasizi K150" and costs like 14 bucks

Huh ? A true XGecu TL866 Plus w/o any extras was about $50 but is now discontinued in 2023. The XGecu TL48 is the new model and is still about $55 US dollars with free shipping from China.
You do not want some cheap knock off as a real one will pay for itself in just one use !!! Where do you live ?
Go on Ebay and try to find the "XGecu Official Store" and check it. Just an example: https://www.ebay.com/itm/195756197503
(yes there are some good clones but I prefer the original XGecu made units, and will get another when times comes)