Have no schematics, nor service manual, trying to rescue this huge work of
art tv from the dump...
symptoms: picture goes off and on repeatadly once per second, colors are
way off, sound OK. Scoped the RGB signals going to the CRT board and
indeed they all go on and off as the picture does. Checked for poor
solders on the main board and the power supply board, only found one
transistor with weak joints, but the problem persists. I didn't manage to
make the problem go away or get worse by banging all over the place, so it
does not seem to be an intermittant connection, maybe a permanent
disconnect?
Going out of the PS board, one of the supplies (orange wire in the 5 wire
cable) is marked as 24V on the board, but it is actually 20V, yet it is
stable on the scope. When disconnected the connector going to the main
board (removed the load) the voltage rises to 24V, so possibly somthing
oveloads it.
Your help is much appreciated.