Quote:
Originally Posted by ostlar
Hi, I am working on a dead JVC TM-1500PS video monitor.
It is in great condition, other than it does not power on.
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Another important piece of information is whether or not the high voltage is kicking on or not.
Use a frequency app to see if you can detect a 15kHz spike when the set is switched on. Turn on the app, then watch what happens when you switch on power to the set. It might turn on briefly and then switch off when it goes into protection. Or it might just be on and fine. The app I use on my android phone is called Spectroid, but there are lots of them out there for free.
It the high voltage isn't turning on, then I would suspect that the B+ is correct at 129V because it's not being loaded. Your test with the bulb shows it regulates when it's loaded.
So check to see if you're getting 15.1kHz and then you'll know if the HV is working. That in itself won't tell you what to fix, but it will get you closer to a cause
The fact that you get 110V when you load it is also suggestive, but you also might have a weak power regulator IC (IC901), which could show issues only under load
Not sure if I can be of any more help, but hopefully that gives you some paths to check out