Mother board boot problems!

[kipper]

Has anyone any experience with motherboard repairs or common faults? I have 5 'STINKPADS' (UNLUCKY ME!), all with the same beep code & no bios screen & no boot! All lights OK Disk & fan working.
Beep code is 3,3,1. Models are A20m/20p & T20/21/23. Have tried all the usual, processor re-seat, bios Bats & Ram in Ram out, nothing works, however the T23 can be intermittent! I know the code suggests the ram or mainboard, but there must be a common denominator! Please give me any info you can, or solutions you have tried in the past, with results.