Submitted by: Steve Webb
When I worked for Radio Rentals as a fresh faced youth we encountered all ages of TV from the very modern to the very old. One of my service calls was to an elderly lady who rented a fifteen year old Baird 420 17″ 405 line only TV. The picture looked very dull and tired and exhibited both low width and height. Voltage tests on the main HT with my trusty AVO 8 indeed revealed low HT. The old selenium rectifier had gone high forward resistance.
My solution was to fit a nice new silicon BY127. I can’t remember if I incorporated a surge limiter. Experience tells me I should have done with the events which were about to unfold. The replacement rectifier produced a superb picture and a delighted old lady. The next day however, I received a call from her which just said ‘TV exploded!’ The nice new HT rectifier I had fitted had proved too much for the elderly reservoir capacitor and it had sure enough exploded. She said the resulting bang had frightened her to death and I don’t think her nearby budgie was too impressed either.
Oh the inexperience of youth!