This is my Line Output Transformer
The key part of all TV sets is the transformer
which develops the high voltage to drive the cathode ray tube.
The LOPT, as it is known, is also pressed into service to provide
subsidiary voltages for many other parts of a TV's circuitry.
Energy that would ordinarily just go to waste as heat is harnessed
to provide things like power for the CRT's heater, voltages to
drive the focus and screen grisd electrodes, and several low
voltage power sources. The LOPT is very highly stressed and a
typical fault is a breakdown within the transformer's windings.
This is usually not an easy fault to diagnose, at least it's
one that could be mistaken for an entirely different fault. The
simple way to find out if a LOPT is faulty is to swap it for
a new one. Unfortunately as there are hundreds of different types
it would be an expensive proposition to carry stocks of all of
them. One of the largest manufacturers of transformers came up
with this little tester which can accurately diagnose most LOPT
faults by emulating the circuitry connected to it in a way that
can determine short circuits between windings, shorted turns
in windings and faulty rectifier diodes in the EHT circuit. Since
I started using it I must have saved many hundreds of pounds
in transformers I never needed to use.
It's now many years since I used this.