a trick i used to use is swapping 2 colours over at the point of origin - in this case the rgb matrix decoder - to see if the colour on the screen changes.
Ah, the connector is asymmetrical, so it only fits in one orientation.
The problem is that I only get something on the screen if those colour signals are disconnected. When I plug them back in, I get nothing on the screen. :/
check any white or gray resistors on the rgb pcb, philips used resistors as fuses.
There is one, and it is fine. Measures 15 ohms.
I am stuck. I don't know what board is at fault. I don't know how CRT should behave, what signals it should get and so on. And this is the last day I can use for repair. After this, I have no more time for it.
check all the psu voltages against the schematic.
if you have HT then the problem is in the decoding or gun-drive area.
There are hundreds of voltages in schematics. They are not accessible (no test points). I would need to hunt down a certain capacitors on the PCB and then solder a wire on the bottom side, then get everything back in place in order to measure it. I dont want to poke around with a few 10s of KV present.
I don't know what HT stands for.
Thanks for help, but time is up. So, I have to give up.
I don't know what HT stands for.
High Tension.
Tension is another term used for very high voltages.