2. From the images it’s hard to tell if it’s just a pin header style pre-AT power connector. The pin header is 90% likely pinned the same as AT but many AT connectors won’t reliably attach to that without an adapter. ( some of my old supplies had a place for both straight pins and standard flat)

I personally would take a few minutes to trace out grounds and power locations before I mess with just wiring it. (I’ve desoldered those to place a normal connector in the past)

That board is earlyish but not that early having “chips” vlsi integration and simms

It's a Daewoo 23050-033001. Early 386DX board.

MikeSG wrote on 2025-07-19, 09:33:

It's a Daewoo 23050-033001. Early 386DX board.

thanks so much guys.

4. I have another question: Does the 386 dx 20 ECS 386/32 has cache ? external cache ? i cant find this info. thanks

5. Im about to buy this for using simm instead of sipp, hope it works ! Could these 2 simm socket work in the sipp socket for using simm 30-pin ?

https://www.ebay.ca/itm/122004729920

https://www.ebay.ca/itm/335559976293

6. even with the model i found no information

It's a Daewoo 23050-033001

i tried Daewoo 23050 only but the board i saw is the not the same.

MikeSG wrote on 2025-07-19, 09:33:

It's a Daewoo 23050-033001. Early 386DX board.

no that early. the IC "chips" says 8939 (1989, week 39)

the cpu on the other hand says 1984, maybe make some sense since the 386s were stupidly expensive prior to AMD 386 introduction in 1991.

I've seen the same Chips 82C301/2/3/4/5/6 chipset with a 91 code.... but Chips has a 82C351/5/6 chipset made in 91 as well.

Can't imagine an earlier 386DX motherboard ... one with no chipset or more than 7-8 ICs in the chipset.

renejr902 wrote on 2025-07-19, 11:12:

4. I have another question: Does the 386 dx 20 ECS 386/32 has cache ? external cache ? i cant find this info. thanks

5. Im about to buy this for using simm instead of sipp, hope it works ! Could these 2 simm socket work in the sipp socket for using simm 30-pin ?

6. even with the model i found no information

Doesn't look like the ECS 386/32 has cache (https://theretroweb.com/motherboards/s/ecs-386-32)

Simms work in place of Sipps

Can't find any info either. May be able to find a datasheet on the chipset though.

Looks like the motherboard that was in my ex wife’s leading edge that her parents gave her in 1989. Leading edge and daewoo were closely linked.

The PC came with a 512 KB ati vga wonder, 1mb ram, 40 mb seagate 251a drive, the rare 386dx 16, and that proprietary variant of the AT power connector. I remember that solitary onboard ide connector and the atx like ports on the back. keyboard might have been on the side of the case if I remember right. my bad, keyboard was on the front with a 90 degree connector.

Let me see if I can find the model…

edit: this is close.. https://theretroweb.com/motherboards/s/leadin … pro-model-d3-25 layout is a little different. clock speed is different.

Rom chips say “D3” but it doesn’t look like the D3 on the retro web. It’s nothing currently listed in microhouse. I spent a lot of time in that leading edge case working on modems, network cards, sound cards, 3.5 floppy drives, hard drive up grades, ram upgrades etc.

Could you post a picture of the on board ports? I’ll upload it to the retro web if you like.

some others pictures of my 3 386 motherboard. Only the Daewoo dont work yet

https://postimg.cc/gallery/g8F3283

you can upload them, no problem

i tried for 3 hours cant get the daewoo motherboard to boot. the 386 dx 16 cpu is good i tested it in the ecs 386/32.

Any ideas ? thanks guys

renejr902 wrote on Yesterday, 02:55:

i tried for 3 hours cant get the daewoo motherboard to boot. the 386 dx 16 cpu is good i tested it in the ecs 386/32. […]
Show full quote

i tried for 3 hours cant get the daewoo motherboard to boot. the 386 dx 16 cpu is good i tested it in the ecs 386/32.

varta leaked battery didnt shor any line, all tested good.

i added a rechargeable 3.7v battery that is at 2.4v.
The power led on the motherboard only turn on since i put a battery.

( by the way, we tried to solder pins on the 1mb 30 pin simm do make them sipp, but the pins are not very stable, i will buy 30-pins simm socket, if someone can tell me which one to buy and where, otherwise i will takr a chance, i need for than 2mb.

Any ideas ? thanks guys

renejr902 wrote on Yesterday, 02:55:

i tried for 3 hours cant get the daewoo motherboard to boot. the 386 dx 16 cpu is good i tested it in the ecs 386/32.

Any ideas ? thanks guys

Do you have a post code card? Does it give any indication that the board is trying to boot?

Did you fix those traces that were eaten away by the battery?

Anonymous Coward wrote on Yesterday, 04:46:

Did you fix those traces that were eaten away by the battery?

Good point. At least three of those traces look open. Can you test them with a multimeter to confirm that they are no longer connecting the vias?

I don't have a post code card. I cleaned the 4 trace i doubt about. But the the contact was still good when i tested them with multimeter. I will still repair them later, if you think i should do it. thanks for answer

Why the daewoo board only have a 5 pin connector for the keyboard, not the rounded one for the at keyboard. i dont have any adapter for connecting a keyboard. i will have to build it.

There must have been a cable that came with the motherboard/case to reposition the AT keyboard connector.

Everything that's reseatable, including the RAM should be cleaned with a toothbrush + isopropyl alcohol to remove oxidisation.

I have had a board that wouldn't boot because of RAM slot oxidisation, and another board of cache oxidisation....

An ISA post card analyser card should show numbers without the video card inserted. But requires CPU, RAM, BIOS working.

MikeSG wrote on Yesterday, 08:25:

There must have been a cable that came with the motherboard/case to reposition the AT keyboard connector. […]
Show full quote

There must have been a cable that came with the motherboard/case to reposition the AT keyboard connector.

Everything that's reseatable, including the RAM should be cleaned with a toothbrush + isopropyl alcohol to remove oxidisation.

I have had a board that wouldn't boot because of RAM slot oxidisation, and another board of cache oxidisation....

An ISA post card analyser card should show numbers without the video card inserted. But requires CPU, RAM, BIOS working.

ok i will do the ram and other with alcool at 90%.
I dont know if it was a good idea, but i cleaned the battery leaked again with vinegar. i posted more pictures. But the co tinuity is ok when tested. im not a electronic tech, but my father is, we will work on this motherboard again this morning. Thanks for your advices and help its really appreciated

i will buy a post card, but it can take time to receive it

renejr902 wrote on Yesterday, 10:23:

ok i will do the ram and other with alcool at 90%. I dont know if it was a good idea, but i cleaned the battery leaked again wi […]
Show full quote

MikeSG wrote on Yesterday, 08:25:

There must have been a cable that came with the motherboard/case to reposition the AT keyboard connector. […]
Show full quote

There must have been a cable that came with the motherboard/case to reposition the AT keyboard connector.

Everything that's reseatable, including the RAM should be cleaned with a toothbrush + isopropyl alcohol to remove oxidisation.

I have had a board that wouldn't boot because of RAM slot oxidisation, and another board of cache oxidisation....

An ISA post card analyser card should show numbers without the video card inserted. But requires CPU, RAM, BIOS working.

ok i will do the ram and other with alcool at 90%.
I dont know if it was a good idea, but i cleaned the battery leaked again with vinegar. i posted more pictures. But the co tinuity is ok when tested. im not a electronic tech, but my father is, we will work on this motherboard again this morning. Thanks for your advices and help its really appreciated

i will buy a post card, but it can take time to receive it

cool i will receive the post card today, i bought it on amazon

I think the leading edge / daewoo keyboard headers incorporated should map directly to the 5 pin at connecter. Maybe this thread will help you identify the pin put by following the traces back to their sources.

AT Keyboard circuit diagram

edit --

The motherboard came from a Leading Edge DC-4010

https://wiki.preterhuman.net/Leading_Edge_DC-4010

http://typewritten.org/Systems/
Leading Edge
DC-3010 Model D2 10 MHz .....ionshivus
DC-3010E Model D2 12 MHz
DC-3110 Model D3/SX 16 MHz
DC-3310 Model D3/MC 16 MHz
DC-4010 Model D3 16 MHz .....detritus

Probably worth while checking to make sure or or more of those really old old tantalum capacitors didn't pop.

Often the easiest what to detect that is to check to make sure that none of the power pins on the motherboard ( 2,3,4, 9,10,11, or 12) are going straight to ground.

douglar wrote on Today, 00:56:

Probably worth while checking to make sure or or more of those really old old tantalum capacitors didn't pop.

Often the easiest what to detect that is to check to make sure that none of the power pins on the motherboard ( 2,3,4, 9,10,11, or 12) are going straight to ground.

the isa card analyser dont do anything, it doesnt light on at all. is it because the voltage is not working in isa slots ?

all voltage works at 2,3,4,9,10,11,12