Most repairs are either repetitive or have simple solutions, although they aren’t always as simple as they once were (thanks to the increasing complexity of modern sets). Obviously, I cannot tell you all the stories about blown fuses or easily-diagnosed transistor failures, as you would fall asleep. As a result, I try to keep to the stories that are interesting (hopefully) or have a twist in them.

A good example of the latter was the rear-projection TV that came in with a colour purity problem. A purity error refers to a spurious colour patch and in CRT sets, you adjust the yoke in and out and rotate the purity ring magnets so that the screen is filled with only one colour, as selected on a pattern generator.

Normally, you do this in turn for Red, Green, Blue and finally, White. However, before proceeding, you first make sure that the set is degaussed and is correctly aligned to the Earth’s magnetic field. It must also be well away from all other sources of magnetism.

Items Covered This Month Philips 43PP9251/79 rear projection TV (A10 PTV 2.0 chassis) NEC FS8002 TV set Philips 32PW8806/79R TV set (MG2.1E chassis) Sanyo CP32WF2-00 TV set (EB7-A chassis) Sony KV-ES29M31 TV set (AG3 chassis) Teac PLH4220 SD/4942 plasma set