cctech Digest, Vol 96, Issue 5

I find that the only way to be sure I have cured the fualt is to know what the fault was. Replaicng parts until the fualt seems to go away is very unsatisfactory (particularly with intermittent faults), you might well have distrubed a bad connection when replacing some other part, for example. I have to say that you were very much 'thrown in the deep end' by having an H7140 PSU as one of your first repairs. I'd not wish that on anybody :-) With vintage machines, you often hgave to repair to compoent level for the simple reason that you can stil lget the components (even if they are not still being made, there are likely to be NO ones around), but you can't find _known-good_ spare bartds, etc to swap in. I couldn't repair my HP9800s as HP intended (by repacing boards until the machine works) becasue finding a known-good HP9800 board set is imposible. FortunatelyI am not afraid to use a logic anaylser... -tony