I'm a moron. I was searching for "G 486PLB 3" and "G486PLB3" I should have searched for "G486PLB"

This is really close--
https://www.arvutimuuseum.ee/th99/m/I-L/30557.htm
JOINDATA SYSTEMS, INC. - G486PLB

The extra socket is clearly a 80487SX socket. Duh.

My version's got the Optibus slot and an extra jumper J101 that may switch between the different proprietary local buses, if I had to guess.

Looks like the jumpers were harvested from the Video/IO card, but the image here looks like it might have some settings I can copy--

Pre-VESA Proprietary 32-bit Local Buses?

Now that's a weird board. It has an OPTi local bus slot, AND another proprietary VLB-like slot. They should have threw in a couple of MCA slots for good measure.

Your extra socket should be for Weitek 4167. It looks to small to be a 487SX socket.

Thanks for the info about the Weitek 4167. Makes sense.

I finally got it to post-- Yes, the VGA bios color cycles.

It isn't healthy though.

1) After giving it power, I have to hit the reset button a couple times before it posts. Is this a sign that one of the secondary chips is failing?

2) I tried several different simm groups until I found a set that doesn't give the dreaded 40 column "Parity Error ????" when it tries to load a boot sector. Probably just the fact that I tried so many different sets cleaned the contacts. The ram had passed memtest on other boards. Seems corrected on the surface, but memory issues can crop up again in weird places..

3) Now I get a "floppy controller error press F1" message when it tries to boot. I verified that the floppy is set up correctly in the bios and the cables are connected correctly. After pressing F1, it runs the floppy like it is trying to boot but it is too quiet and then it reports that the diskette is not bootable. I swapped out the Local bus card for a known good ISA IDE controller but I get the same thing. I'm using a known good floppy cable, power supply, and floppy drive.

So looks like the BCP damage from the NiCd battery was is bad enough to prevent the board from booting.

The most difficult projects I've done before are some cap replacements and to fix some dislodged surface mount connectors.

I've never done trace repairs on a bother board.

Should I try a trace pen first?

Any recommended brands or walk throughs?

It doesn't look that bad, I think it can be saved with some patience.

First use some acid (vinegar, lemon juice) to neutralize the alkaline mess from the battery. Then, clean the area thoroughly with alcohol and examine the damage.

For traces that have dark spots, you can use a fiberglass pen or something similar to scrape the corrosion and expose the copper. If a trace still has continuity, you can then tin the exposed copper and cover it with solder mask paint (or just nail polish).

If you find broken traces, you will have to bridge them with wire (you can bridge on the back or the front of the board depending on the case).

If the board still doesn't work properly, you may want to remove some components in the affected area (such as the keyboard connector) and see if the corrosion has killed traces underneath them. The J14 jumper header looks like a good candidate for removal, traces near it look a bit dodgy.

TheMobRules wrote:

First use some acid (vinegar, lemon juice) to neutralize the alkaline mess from the battery. Then, clean the area thoroughly with alcohol and examine the damage.
For traces that have dark spots, you can use a fiberglass pen or something similar to scrape the corrosion and expose the copper. If a trace still has continuity, you can then tin the exposed copper and cover it with solder mask paint (or just nail polish).
If you find broken traces, you will have to bridge them with wire (you can bridge on the back or the front of the board depending on the case).

Thanks ! I was taught similar decades ago and your explanation affirms that same method.

TheMobRules wrote:

It doesn't look that bad, I think it can be saved with some patience.

Thanks, I appreciate the info--

I would recommend desoldering the J14 header for cleaning. Once you've scraped off all the trace coating, do another rinse with acetic acid. Rinse off the acetic acid with water, then rise that area with isopropanyl. I use a sowing needle to clean out the vias. For the smaller vias, use solid core wire to "floss" the holes. Looks like you have about 7 traces which need patching. I usually patch via to via, preferably on the bottom surface so that it looks nicer from the top. I recommend 30 or 32 AWG wire for the patching.

EDIT: That's a really interesting combination of local buses. Do you have cards for both slots?

I have a single card for the JOINDATA proprietary card that combines IO, IDE and ET4000 video on a single board. I don't have any optibus cards.

I scrubbed down the damaged area. The traces looked good. Didn't test with the multi-meter though. I re-seated all jumpers. Seems like the mystery jumper 101 in the corner of the board may have been dirty. After removing and re-seating it, I don't have to press reset 2-4 times before the board posts now. The board posts as soon as the power is turned on. Cheers to small victories.

While it posts fine now, I can't get it to boot. Here's what I've tried:

• Known good memory & CPU's
• I've tried the PLB card as well as a known good ISA Multi-IO card w/ Trident ISA card.
• Known good Floppy drive, known good cable correctly attached
• Bios shadowing turned off
• Relaxed memory timings

Reports FDD error after the memory test when it should be doing the floppy seek, faint motor whir, no activity light.
Reports No Disk when it tries to boot.
Can't detect any IDE drives in the BIOS.

I'll try pulling the J14 external battery plug next.

I would try a simple ISA video card and simple ISA ide/floppy controller card first and forget that special addon card until you get the board to boot proper. It has regular ISA slots so you could try a number of things. Once you get the board to boot proper then you can work on that card but like many other combo cards... they are just not are worth the effort IMHO

Made by Tekram:
http://www.win3x.org/uh19/motherboard/show/3335

Interesting. Tekram G486PLB was slightly different than the G486PLB-3.

G486PLB-3 has a jumper 101 in the top right corner and has the eisa looking, possibly optibus slot near the power.

Noted, entries split, the -3 version now has its own page:
http://www.win3x.org/uh19/motherboard/show/6849

You guys are great. I'll get some more boards posted for you.

Also, I know where the driver disk is for that board, just happens to be 3 times zones away. I'll get that stuff as soon as I can.

Anonymous Coward wrote on 2019-11-14, 00:14:

Now that's a weird board. It has an OPTi local bus slot, AND another proprietary VLB-like slot. They should have threw in a couple of MCA slots for good measure.

Your extra socket should be for Weitek 4167. It looks to small to be a 487SX socket.

MCA didnt excist in that period.. And Opti bus is the precursor of VESA LOCAL BUS.
MCA came after VESA LOCAL BUS.. when also PCI came populair.

Well, ATi begs to differ, considering they released Mach32 cards in ISA, VLB, PCI, EISA and MCA all at the same time.
MCA came out in 1987, and lasted until about 1994 I guess.

OPTi local bus came out slightly before VLB, and they were actually competitors for a short time.

I got the driver disk!!!

This is probably a 1.2Mb disk and my 5.25 drives are not good .

I have a 360K drive that won't read this disk and a 1.2MB that now spins & seeks after a bunch of cleaning, but always reports "track 0 bad disk" when I try to format a blank disk.

Odds are that the data has not survived after 30 years, but the jacket and media looks like it is physically in good shape.

If anyone in the US wants to try reading the disk with a known good drive, message me a mailing address and I will send you the disk.

Ah too bad I'm not in the US. I'd do it otherwise