Hello There, I have a SONY MONITOR (PVM-20M2MDE) First fuse was blown and chopper(2SD1878) was destroyed. I replaced the chopper and it destroyed again (anything else around was fixed, checked OK). I had to open the chopper and see the horizantal drive signal, it is only 5 KHz which certainly is too low for FBT to tolerate. I replaced the horzantal IC (upc1377c) and the signal is still the same. Here comes the headache ... there are a lot of feedback paths from FBT to this IC, which affect the frequency, I can't connect the chopper (to have feedback)as certainly it destroys again. Has anybody experience with such a problem ? I should add that the destroyed choppers had all pins shorted (this usually means an error in drive circuit). Any help will be appreciated. Dario.
- posted
18 years ago