I have this Grundig M72-105 IDTV chassis CUC1852 which shows very symmetrical color distortions mainly in the top corners of the CRT. The distortions are of a rainbow moiree type and very pronounced. Using my external degausser does influence the picture but when the degausser is switched off, the old phenomen reappears unchanged.
The TV set works fine, I am thinking about a defective mask in the picture tube Tube data is TOSHIBA A68KZN696X99
Is there any further information on this problem ?
TIA