This page is dedicated to the 2 people who polished my problem -solving skills, both
general and electronic. They are my old headmaster Mr W Egner, and Patrik Bladh,
video engineer and master fixer!
In 35 years of fault-finding and repairing electronics ranging from valve (tube)
circuits to surface-mount solid state, the same general principles apply. My colleague
Patrik Bladh and I worked together in Switzerland in 1977 - he was Swedish, with
his own special command of English. The quotes I have put in here (marked *) are
typical of his inimitable style.
1. It always shall be simple *
This is well worth remembering. Of course it isn’t
always simple, but it is easy to think that something is going to be complicated
merely because one only has a dim idea of how the thing works. People usually blame
the part of a system that they don’t understand - which is usually the electronic
bit. A friend of a colleague of mine was sent by his employer to sort out a fault
on a piece of equipment they had supplied to a very well-known establishment in Pasedena.
When he arrived on site he found the equipment was switched off - in England a switch
is off when it is up, and in America it is the opposite. Ah well, it was rocket science!
2. Don’t get bogged down
My headmaster showed me how to solve mathematics problems
by approaching them from different directions. Sometimes the first thing you try
is based on wrong assumptions, and the longer you stick with one thing the harder
it is to leave it and try something else. A fault will almost always give a trace
of several symptoms. If you are getting bogged down, take a break - go to lunch or
make an excuse to check something in the car. It clears the mind.
3. It always shall be power supplies *
The power supply is normally the most stressed
part of electronic equipment. Devices there undergo a lot of thermal cycling, which
results in mechanically- induced failures. They are usually also under a lot of electrical
stress. Don’t forget to check the accuracy of the voltages. Sometimes quite strange
effects come from power supplies that are just out of calibration.
