At 11:05:55 Wed, 16 Sep 2009, The Natural Philosopher wrote:

Indeed. Most electronics is super reliable, and generally its one stray
thing that goes. Identify it and replace it and all is well.
Its the identifying that is the problem.

How true...

I had a TV years agpo that randomly lost colors..hitting it restored
them. One day even that failed to work.

My CRT monitor is on the blink. It will run perfectly for hours and
then the picture goes almost black. The slightest tap on the casing is
often enough to bring it back to life. Sometimes it takes a thump.

I ran it caseless and prodded things with a long plastic knitting needle.

I've tried that, but frustratingly I can't find the fault. The soldered
joints on the PCB all seem to be sound. It will be shame to dump this
monitor since it's less strain on the eyes than my flat panel screen.

Old valve sets are similar - the caps all dry out. Many a valve radio
will spring to life after all the paper and electrolytic caps are replaced..

I have a 9-valve National HRO that still works after 70 years...

--
John Legon