I recently acquired a GoldenGate 486SLC with 4MB SIMMS on board.
I suppose there were less GG's in the field, so I'm afraid there was/is less GG expertise around**. I have all BridgeBoard models and CPU clip-ons, but the only GG I ever saw (over 10 years ago) had about the same problem as yours. Good luck fixing it, and I'd still like to find a working GG to play with.
**At least on this side of the pond; the BB's were 'from' West Chester PA while I believe the GG's were from Germany.