Hello all
I have encountered a problem with some very vintage hardware and am unable to find an answer anywhere on the internet so would like to tap in to your collective wisdom.

I have 3 Compay SLT laptops. one 286 and two 386.
All needed Dallas mods / replacement. The 286 has worked perfectly but the 386s are being a pain.
They both power on showing errors "167-RTC lost power" and "162-System options not set-(Run Setup)". You can boot to a floppy and run the bios setup BUT on reboot you get the same error.
The errors are the same with the factory dallas chip, a battery mod and a replacement module from Necroware.
I have tried compaq diagnostics 8.0 (which worked fine on the 286) and 8.1 (bootable 1.44mb image from here: https://archive.org/details/CompaqDiagnostics … 091492Rev.A1992). I've seen some notes of problems with booting dos 6.22 so have tried 3.30, 3.31, 4.01, 5 and 6.0.
I was going to blame dodgy soldering but as i get the same issues with a laptop in factory condition and a modded one i am stumped.
Is this an issue anyone else has encountered?

FYI I also have the dock and am in the process of pin-mapping it so i could make a "small" version with an ISA socket for a sound card.

Any advise would be greatly appreciated as my first PC was a 386/SX and i'd love to have another one.