View Full Version : Sony PVM-1220


devoid
08-09-2009, 12:20 PM
I'm having a problem with the pin circuit. I replaced some bad caps with no change. I'm suspecting the pin driver (PNP signal type) or output (SG613, horrors). I have no schematic. Nice pin waveform on the base of the driver horizontal only at collector, emitter and gate of the output. I have swapped the driver yet or measured all the discreets out of circuit as I just got a new desk and had to tear down the computer system but I'm back up and running now and don't feel like it's all going to end up in me lap. So, what should I look for or replace? Or does anybody have a print for this or similar? Thanks!

kx250rider
08-09-2009, 01:35 PM
How badly bowed is it? I haven't worked on a PVM-1220, but I've seen a lot of pin problems in 1980s-90s Sonys. Usually it's the pincushion transformer, which will burn open due to a leaky electrolytic cap, and sometimes the pin driver shorts. It's a small 3/4" tall, 1/2" diameter round coil, with black tape wrapping and (I think) 5 pins. If it's all overheated-looking, and the tape is curled up, check it... All of the 1989-mid-90s XBR sets were subject to that. But this may not apply if that set is a different circuit. I haven't seen one with the SG-613 since the 1978 models, thank Goodness. But again, I have little experience at all in the PVM series.

Charles