Gentlemen,
I'd welcome any constructive suggestions on how to proceed with tracking down this elusive and annoying fault. The problem presents as a blank CRT screen on the network analyser I'm working on currently. Inititally I discovered the screen was being blanked not just during re-traces, but *permanently* - there appeared to be a rogue logic signal somewhere responsible. However, it turns out the problem goes away and the screen instantly comes back when I press and tap on various areas of the motherboard or the cards that slot into it. The trouble is, there doesn't seem to be one specific area that's susceptible to this tapping and bending. First it appears to be a bad joint/ connection on the motherboard, then it's one of the slot-in boards and then next time again, a different board - but all capable of misleadingly appearing to be the site of the poor connection. Any ideas as to how to narrow the search area right down to something manageable? Thanks.