An old PC I rescued from the tip recently was sporting a nice little 386DX40 motherboard - one of those soldered-on-chip deals. Unfortunately the battery had leaked and although it did POST, it wouldn't recognise the keyboard. With sadness I decided it was toast and hung it on the wall of my outside toilet; a little object d'art to stare at while I contemplated life, and hid from my kids.
But, while surfing the interwebs the other day, I happened across this site:

http://members.optusnet.com.au/spacetaxi64/

Amongst other things (check out all that C64 info!) Jack, the site owner, offers:

"Repairs to: Vintage Computers & Consoles, and almost anything Electronic"

It turned out that Jack lives just down the road, so I retrieved the board from the loo, dropped it round to Jack’s, and a few days later it was fixed and ready for action!

The list of fixes and some pics follows:

1386 Motherboard - with Battery acid damage. Labour = ( 2.5 Hrs)
2- Replace R4 (1k) broken leg.
3- Replace CT4 - (16uf 10v) Faulty.
4- Clean short under CT4
5- Repair cut track at CT4
6- Repair cut track to CT5 (Linked to Ct4 repair)
7- Repair cut track near D8
8- Repair cut track to J1
9- Re-seat IC 8618, not tight in socket
10- Remove 5-pin Din plug, clean underside & re-solder.
11   (Note: J1 goes to pin 31 of IC 8618)
12   (CT4 = 16uf 10v, CT5=10uf 25v, R4=1K. )
13
14Video Card = OK, PSU=OK, Keyboard = ESC Key sticky
15Tested Booting to DOS & Windows 3.11 = Works.

The board, fixes visible near the DIN connector:

ISA Tseng ET4000AX '2 the MAX'. This thing was spasmodically detecting my VGA monitor as monochrome on start-up - something to do with the card's BIOS? Anyway, a search of Vogons' threads turned up a little utility called 'coloron.com', which forces it back into 256 colour mode.

Goldstar IDE controller:

Seagate ST3096A (90mb):

5 ¼ floppy drive:

Up and running with DOS 5, 8mb's of goldstar RAM and a Sound Blaster Pro 2 to finish it off. It's nice and stable and gets a score of 9.39 in SpeedSys, which is pretty good I think, particularly when you consider that it has no cache on the board.