SONY CRT RGB signal trouble

[jbaudrand]

Hello, after succeed to restore switch on my bros' 6218+ I'm trying to figure out what is the pb with his CRT, as the video show, the correct RGB is diplayed half a second and the colour are altered after that. The amstrad is not faulty because it has been tested ok on my amstrad monitor and my Sony CRt (not of the same type). The scart cable was done by retro Computer Stack and modified by my uncle to add a power cell AA connected to the appropriate pole to allow switch in RGB mode. Maybe soldering need to be check, but I doubt it because it's ok on my sony CRT, that switch directly in RGB. Any suggestion are welcome

[jbaudrand]

[eto]

I once had a TV which did not work with a single AA cell but 3V then worked. 

[Bryce]

Check that all the GND pins in the SCART plug are connected to the CPC GND pin.

Bryce.