https://www.ultimateretro.net/en/motherboards/9758
Not all that useful since it's unknown and with no documentation. Could be a chance to fill in some of the gaps if you can get it running and/or get a copy of the BIOS.

[edit: RAM might need to be in pairs, so you might need 2 sticks]
[edit2: actually, not quite the same board. You've got rev B1, the board I linked is rev A2. Different BIOS (A2 is Pheonix, B1 is AMI) and change from 30 to 72 pin RAM]

snufkin wrote on 2022-04-08, 11:14:

https://www.ultimateretro.net/en/motherboards/9758 Not all that useful since it's unknown and with no documentation. Could be a […]
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https://www.ultimateretro.net/en/motherboards/9758
Not all that useful since it's unknown and with no documentation. Could be a chance to fill in some of the gaps if you can get it running and/or get a copy of the BIOS.

[edit: RAM might need to be in pairs, so you might need 2 sticks]
[edit2: actually, not quite the same board. You've got rev B1, the board I linked is rev A2. Different BIOS (A2 is Pheonix, B1 is AMI) and change from 30 to 72 pin RAM]

Thanks, at least now i have some info on it.
As i've said, i tried to turn it on and used the GPU that was originally on the board.

The screen was showing "no signal" but the CPU seems to work as after turning it off i've felt that it was slightly warm.
I've no idea if the damaged tracks can cause the motherboard to suddenly stop working or why the MB doesn't want to show up any kind of screen.
The green filth seems to have come off from the AMIKEY-2 BIOS and the DIN-5 keyboard connector but there is still "green" on the jumper near the Keyboard BIOS.
There are clear signs of corrosion but the tracks leading to the keyboard BIOS seem to have suffered minimal damage and under the board the tracks are fine except for those directly under the battery.

Luke4838P wrote on 2022-04-08, 11:28:

I've no idea if the damaged tracks can cause the motherboard to suddenly stop working or why the MB doesn't want to show up any kind of screen.
The green filth seems to have come off from the AMIKEY-2 BIOS and the DIN-5 keyboard connector but there is still "green" on the jumper near the Keyboard BIOS.
There are clear signs of corrosion but the tracks leading to the keyboard BIOS seem to have suffered minimal damage and under the board the tracks are fine except for those directly under the battery.

Of course they can, I don't see a good photo after cleaning but having seen the "before" I'm sure the board needs more work than just cleaning.
Verify continuity everywhere in the area (don't rely on "seem to have suffered minimal damage") and remove components that may hide surprises, like the keyboard controller socket

konc wrote on 2022-04-08, 11:38:

Luke4838P wrote on 2022-04-08, 11:28:

I've no idea if the damaged tracks can cause the motherboard to suddenly stop working or why the MB doesn't want to show up any kind of screen.
The green filth seems to have come off from the AMIKEY-2 BIOS and the DIN-5 keyboard connector but there is still "green" on the jumper near the Keyboard BIOS.
There are clear signs of corrosion but the tracks leading to the keyboard BIOS seem to have suffered minimal damage and under the board the tracks are fine except for those directly under the battery.

Of course they can, I don't see a good photo after cleaning but having seen the "before" I'm sure the board needs more work than just cleaning.
Verify continuity everywhere in the area (don't rely on "seem to have suffered minimal damage") and remove components that may hide surprises, like the keyboard controller socket

Thanks for the advice.
I am sure too that it needs most likely wire bodging, but what i meant that i was unsure which ones could be hiding the problem.
The motherboard is stashed at work and i need to get it as it's not at home.
It's safe to desolder the AMIKEY-2, i know of the DIN-5 but isn't the keyboard BIOS delicate?

As of the cleaning, a second toothbrush session with white vinegard had the green removed except for two jumpers, despite insisting the green won't come off, if i scrub it off with a small screwdriver or fingers it goes away.

The keyboard BIOS may be delicate, but given the level of corrosion it might well already be dead, and there could be all kinds of muck still active underneath it. This is a severely damaged board and needs stripping, repairing and rebuilding of the affected areas.

dionb wrote on 2022-04-08, 11:59:

The keyboard BIOS may be delicate, but given the level of corrosion it might well already be dead, and there could be all kinds of muck still active underneath it. This is a severely damaged board and needs stripping, repairing and rebuilding of the affected areas.

Then again, we've all seen worse that worked, huh?

But agreed, that board could use a whole lotta TLC.

Luke4838P, if you ask me, please edit your posts so the pictures only appear as attachment thumbnails, and where necessary, position them by using the [attachment=0] ... [/attachment] tags provided by the button next to the file license menu like this:

- that would keep the thread much more readable.

If you include them with the img tags, it's really starting to be hard work to scroll through the posts.
Thumbnails will suffice until someone needs details.

dionb wrote on 2022-04-08, 11:59:

The keyboard BIOS may be delicate, but given the level of corrosion it might well already be dead, and there could be all kinds of muck still active underneath it. This is a severely damaged board and needs stripping, repairing and rebuilding of the affected areas.

True that.
Once i get it back i can get to desoldering the connectors.
Do i also need to desolder the PSU connector\RAM slots?
Anything else i need to do?
It's my first 486 damaged board and i want to make it functional again, no matter what is the damage, it's just a personal project of mine.

Cuttoon wrote on 2022-04-08, 12:42:

Then again, we've all seen worse that worked, huh? […]
Show full quote

dionb wrote on 2022-04-08, 11:59:

The keyboard BIOS may be delicate, but given the level of corrosion it might well already be dead, and there could be all kinds of muck still active underneath it. This is a severely damaged board and needs stripping, repairing and rebuilding of the affected areas.

Then again, we've all seen worse that worked, huh?

But agreed, that board could use a whole lotta TLC.

Luke4838P, if you ask me, please edit your posts so the pictures only appear as attachment thumbnails, and where necessary, position them by using the ... tags provided by the button next to the file license menu like this:
2022-04-08-143744_1680x1050_scrot.png

- that would keep the thread much more readable.

If you include them with the img tags, it's really starting to be hard work to scroll through the posts.
Thumbnails will suffice until someone needs details.

I apologize, i had no idea how to post an attachment.
So, any more advice to help this motherboard?

I also wanted to make the board have the coin cell mod, where do i need to cut the circuit\ place the diode?

Luke4838P wrote on 2022-04-08, 16:44:

True that. Once i get it back i can get to desoldering the connectors. Do i also need to desolder the PSU connector\RAM slots? A […]
Show full quote

dionb wrote on 2022-04-08, 11:59:

The keyboard BIOS may be delicate, but given the level of corrosion it might well already be dead, and there could be all kinds of muck still active underneath it. This is a severely damaged board and needs stripping, repairing and rebuilding of the affected areas.

True that.
Once i get it back i can get to desoldering the connectors.
Do i also need to desolder the PSU connector\RAM slots?
Anything else i need to do?

Difficult to say from these pre-cleaning pics. Looking at what I can see, the top ISA slot looks suspicious, the SIMM slots less so and I really can't see one way or another with the power connector. But bottom-line, just follow the mess and make sure it's all clean (not even a hint of blue-green anywhere), then see what damage is under it and fix that.

It's my first 486 damaged board and i want to make it functional again, no matter what is the damage, it's just a personal project of mine.

Looks like you picked quite a challenge in terms of damage, but the board design is ideal - old, lots of discrete components in an uncramped layout.

I also wanted to make the board have the coin cell mod, where do i need to cut the circuit\ place the diode?

You might not need to. J3 looks like an external battery connector. Just hook the battery up to that. The diode is already there on the board (D1 and/or D2)

Got a pic that shows the board after the first cleaning with white vinegar.
Take note that even more filth/oxide went away with the second cleaning and i might insist with a third and a fourth after desoldering the suspicious components.
Since it's so old might it be the case the board won't boot at all without the battery? I also didn't connect anything besides GPU and keyboard, no HDDs or floppy drives.
I was unable to test it when i first found it due of lack of PSUs and its original one was dead (not even the fan spinned).
I am motivated to bring this board back to life.

Update after some troubleshooting.
Checking the traces with a multimeter revealed that two traces, one to the keyboard AT connector and the other leading to the various slots were damaged and needed wire bodging.
The keyboard bios and the isa slots were unharmed.
Two copper wires soldered on the interrupted segments restored proper connection and now I need to mod the motherboard to place the diode to make a cr 2032 mod.
Now the motherboard is fully cleaned and has been repaired.
If someone can help me locate the charging circuit so I can place the diode, I will welcome any help.

Luke4838P wrote on 2022-04-20, 15:03:

If someone can help me locate the charging circuit so I can place the diode, I will welcome any help.

As Dionb said, looks like header J3 is an external battery connector, with diodes already fitted on the board. 3xAA cells should be ok, probably +ve to pin 1 and -ve to pin 4 (check if pin 4 connects to Ground). RAM might need to be in pairs.

snufkin wrote on 2022-04-20, 15:19:

Luke4838P wrote on 2022-04-20, 15:03:

If someone can help me locate the charging circuit so I can place the diode, I will welcome any help.

As Dionb said, looks like header J3 is an external battery connector, with diodes already fitted on the board. 3xAA cells should be ok, probably +ve to pin 1 and -ve to pin 4 (check if pin 4 connects to Ground). RAM might need to be in pairs.

I wanted to do a cr 2032 on board permanent solution without the external battery, for an elegant look.
I temporarily placed two wires with a diode on the + pole and a cr 2032 battery holder until I will find where to place the diode.