Negative, everything seems to be alright. Probably picture fault.

zami555 wrote on 2025-11-04, 13:13:

I have the impression that the pins in SIS chip, the one close to RAM, are bent. Please check carefully whether there is no short circuit between some of these, or that some pin has lost contact with pcb.

The attachment IMG_20251104_140623.jpg is no longer available

Will check that next days and let you know.

butjer1010 wrote on 2025-11-04, 08:05:

I also didn't saw this other oscillator 🙁
So, if You turn it on without SIMs, and with speaker connected, there is no sound at all?

So let's say the mobo works. What would happen if there were ordinary modules?

99% likely needs the 9-chip SIMMS. I think the keyboard controller is fine... The hex inverter is sometimes different (7404/7405/7406/7407), but the one you have looks like it's for the AMI controller, which is what you already have.
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It could actually be a RAM problem, on the 386DX-40 I have four RAM 30 PINs of 1 MB each, and they are all with 9 chips.

Gavrilo wrote on 2025-11-04, 18:31:

Will check that next days and let you know.

butjer1010 wrote on 2025-11-04, 08:05:

I also didn't saw this other oscillator 🙁
So, if You turn it on without SIMs, and with speaker connected, there is no sound at all?

You will know the ram is problem if without them there are continuous beeps on the speaker 😀
That means the mobo and cpu are 99% ok

O.K. guys, so I connected speaker and whether I put memory modules or not, I got 3 longer beeps in a row, then little pause and then those 3 beeps again. No display on monitor either. According https://members.tripod.com/pc_circus/BiosBeep.htm it is Base 64K RAM failure. What does it mean?

Gavrilo wrote on 2025-11-06, 09:48:

O.K. guys, so I connected speaker and whether I put memory modules or not, I got 3 longer beeps in a row, then little pause and then those 3 beeps again. No display on monitor either. According https://members.tripod.com/pc_circus/BiosBeep.htm it is Base 64K RAM failure. What does it mean?

So probably the guys were right! You need to try with 9chip memory modules. I think the board is ok, just the ram is the problem. Try also with magnifier or microscope to look onto those tiny metal "things" in ram slots. Just to be sure all are there, and there is no bent ones 😀

Roger that butjer, will try to buy and try those modules. It would answer the question why there is that beeping with or without memory modules if we permit that the board needs 9chip modules - if I put there ordinary ones and the board needs 9chip modules, it means like there were non inserted. But there is still the uncertainty about the processor.

Gavrilo wrote on 2025-11-06, 16:00:

Roger that butjer, will try to buy and try those modules. It would answer the question why there is that beeping with or without memory modules if we permit that the board needs 9chip modules - if I put there ordinary ones and the board needs 9chip modules, it means like there were non inserted. But there is still the uncertainty about the processor.

If it gave beeps, that means the CPU is ok (POST order- CPU, RAM, VGA,... so if detects there is no RAM, CPU passed the POST). As i said earlier, look at the ram slots for bent pins, could be the problem also...

Mike, do I have to use all four of 'em? Wouldn't one or two be sufficient?

MikeSG wrote on 2025-11-03, 15:20:

Possibly need 4x 9-chip RAM SIMMs to get it to post.

Some boards like this might also use a Fujitsu type keyboard controller which is slightly different.

Gavrilo wrote on 2025-11-06, 20:23:

Mike, do I have to use all four of 'em? Wouldn't one or two be sufficient?

MikeSG wrote on 2025-11-03, 15:20:

Possibly need 4x 9-chip RAM SIMMs to get it to post.

Some boards like this might also use a Fujitsu type keyboard controller which is slightly different.

For the 386DX you need four 30-PIN SIMMs, two instead for the 386SX and 286.

I think it's over. The board doesn't even beep anymore.

Gavrilo wrote on 2025-11-07, 18:26:

I think it's over. The board doesn't even beep anymore.

Did You somehow damage it, or what? If not, clear CMOS, maybe it will beep again 😉

I removed cache memory chips to see what will happen, then powered the board without them. No beeping. Then put them back, but nothing changed. Next week I am gonna order those simm 9chip memory modules whether the board will work or not. Good to have them anyway. Meantime I will try to "play" with the mobo if I will be able to make it at least beeping again and I will try to change the battery, have one spare left.

Gavrilo wrote on 2025-11-07, 20:06:

I removed cache memory chips to see what will happen, then powered the board without them. No beeping. Then put them back, but nothing changed. Next week I am gonna order those simm 9chip memory modules whether the board will work or not. Good to have them anyway. Meantime I will try to "play" with the mobo if I will be able to make it at least beeping again and I will try to change the battery, have one spare left.

Probably You have bent some cache chip pin. Try to lift them again and check every "leg". If You removed the cache chips, probably there are jumpers that You need to set to make it work. Cool Your head, get some rest, and with empty head put that motherboard on table and continue. With hot head, You can only make damage 😉

Yes, I accidentally bended one pin on one cache. Fixed it. There are no jumpers near caches, so I can't set anything while caches are out.

I haven't found any bended or damaged contacts in ram slots. In one slot there is one green-corroded contact but it has the connection with opposite side of the board. Some green are also in cache slots, will clean them up. It wasn't vissible from outside.

I also noticed missing jumper near battery. There is 1,2,3 - don't know which pair to connect.

And I remember on my JoindataSystems G386SYM there were ordinary memory modules with 3 chips and the i386DX-25. And the board was POSTing.

Gavrilo wrote on 2025-11-08, 06:20:

Yes, I accidentally bended one pin on one cache. Fixed it. There are no jumpers near caches, so I can't set anything while cache […]
Show full quote

Yes, I accidentally bended one pin on one cache. Fixed it. There are no jumpers near caches, so I can't set anything while caches are out.

I haven't found any bended or damaged contacts in ram slots. In one slot there is one green-corroded contact but it has the connection with opposite side of the board. Some green are also in cache slots, will clean them up. It wasn't vissible from outside.

I also noticed missing jumper near battery. There is 1,2,3 - don't know which pair to connect.

And I remember on my JoindataSystems G386SYM there were ordinary memory modules with 3 chips and the i386DX-25. And the board was POSTing.

That's the spirit!!! After rest, You see that everything is easier now 😉
Maybe the board You have mention in Your first post, has similar jumper for battery, Try checking there, and maybe the settings are the same. Board really looks like Yours.
As far as RAMs, You'll never know if You don't acquire 9pin ones 😀 The problem will be if it doesn't work with them also, but probably it would work.

One thing i didn't ask You - Is there any sticker from the lower side of lowest ISA slot? Older motherboard can have stickers there. Maybe there is some kind of info about the board.

The board I posted in my first post is the one I have, it is the one on picture in my post. The link about the closest match was just an example what I have found among those schematics because mine isn't there. It's the only one we are discussing about. No sticker on ISA slots.

Doesn't matter because IT IS WORKING! I put jumper onto 2nd and 3rd pin nearby the battery. I can't believe that all the fuss I caused was because of one missing jumper.

So for people who mentioned that it will probably not work with this 25MHz processor or with ordinary memory modules, you were fortunately wrong 😀. Thanks to everyone. Now I just have to get appropriate PC case, because this board is to big for ordinary one.

Gavrilo wrote on 2025-11-08, 11:10:

The board I posted in my first post is the one I have, it is the one on picture in my post. The link about the closest match was just an example what I have found among those schematics because mine isn't there. It's the only one we are discussing about. No sticker on ISA slots.

Doesn't matter because IT IS WORKING! I put jumper onto 2nd and 3rd pin nearby the battery. I can't believe that all the fuss I caused was because of one missing jumper.

So for people who mentioned that it will probably not work with this 25MHz processor or with ordinary memory modules, you were fortunately wrong 😀. Thanks to everyone. Now I just have to get appropriate PC case, because this board is to big for ordinary one.

Excellent final result, congratulations 🍾
Now, however, given the number of empty banks, I would look for RAMs identical to the ones you have, to fill all the empty banks, the total memory would go from 4 MB to 16 MB, I don't know if they are easy to find, but maybe if you are lucky 🍀, you could find others similar ones, that is 2+1 chip, maybe the same speed, you need another 12 pieces of 1 MB.