Peale
Active member
I have a batch of 25K7000 from a client that require repair. Almost all of them have been BADLY hacked.
This one, in particular, has me scratching my head.
1) fired it up, before doing work. Noted presence of black "blob" on side of screen. I can get it to nearly disappear by adjusting vsync, but not entirely.
2) cap it. Lots of solder rework. Colours are better, but the black blob remains.
3) for giggles, replace the flyback. Blob issue remains, but appears to be not as severe.
4) while going over the chassis for abnormalities, I note that the 4th wire on P202 has been cut out. I can't seem to find any technical docs on why removing that might be a good idea, so I'm just about to replace the assembly with one from a donor chassis. If I've traced the neckboard correctly, this may help with the blue that appears to be nearly completely on, all the time.
5) shrinking the picture makes the blob get much bigger.
I suppose one of my next moves is to replace the vertical IC.
This one, in particular, has me scratching my head.
1) fired it up, before doing work. Noted presence of black "blob" on side of screen. I can get it to nearly disappear by adjusting vsync, but not entirely.
2) cap it. Lots of solder rework. Colours are better, but the black blob remains.
3) for giggles, replace the flyback. Blob issue remains, but appears to be not as severe.
4) while going over the chassis for abnormalities, I note that the 4th wire on P202 has been cut out. I can't seem to find any technical docs on why removing that might be a good idea, so I'm just about to replace the assembly with one from a donor chassis. If I've traced the neckboard correctly, this may help with the blue that appears to be nearly completely on, all the time.
5) shrinking the picture makes the blob get much bigger.
I suppose one of my next moves is to replace the vertical IC.

