On Sat, Apr 29, 2017 at 5:45 PM, Aaron Jackson <aa...@aaronsplace.co.uk> wrote: > I have measured these again because I thought they seemed a bit > strange. I must have probed the wrong pad on the circuit board earlier > (my probes don't fit in the CRT header). > > Here are all the voltages and they don't seem too promising: > > pin 1, green, 4.3v, should be 50v to 80v > pin 2, yellow, 6.6v should be 70v to 100v > pin 3, brown, 12v - fine > pin 4, black, 0v - fine > pin 5, white, 0v, fine, goes to case ground > pin 6, red, 0v, should be 400v to 800v > pin 7, blue, 0v, should be 400v to 800v > > The voltage from the brightness control ranges between 2.4v and 5.5v, > and matches pin 1 above.
This looks very much like a problem with the horizontal deflection circuit. Maybe the flyback transformer, maybe not. Without a 'scope, troubleshooting is going to be difficult. But start by testing the horizontal output transistor (Q202 on the printset). For a start, just check it for shorts and opens. But if it has failed, don't just replace it, as a problem with the flyback transformer can destroy the new transistor. -tony