My RCA P52920BL 52" projection doen't turn on. For a couple of days the set would turn, and I would see an arc on the screen. Next the tv would turn on, but after a minute it would shut off for a couple of seconds then turn on. The set would do this 4 or 5 times then stay on. Then it wouldn't turn on at all. I can here it trying to turn on through the speakers, but it doesn't. I am a tech, and know the problem is in the power supply, but don't have a service manual... Henry
The RCA P52920BL uses the PTK195 series chassis. The most common reason for the set not turning on is a shorted flyback transformer. To check this, measure the B+ when the set is plugged in - it should be around 145 volts. When you turn the set on, see if the B+ drops down at all. If the flyback is shorted, the set will try to start but the flyback draws too much current. The microprocessor senses this and immediately shuts the set back off. To confirm, unsolder the jumper wire bringing B+ to the flyback and put a 100 Watt bulb in its place. Turn the set on and if the flyback is shorted, the set will now stay on but the bulb will glow as bright as if it was plugged into the wall. If this is the case, replace the flyback. Let me know what you find and we will take it from there.
Posted on Aug 25, 2007
Well, the flyback is the transformer with the thick red wire coming out of the top. It is right along the back of the main board, and has the 2 controls labeled FOCUS and SCREEN on it. If you do not know what a flyback is, you really should not be messing around inside a projection set. I strongly suggest allowing a qualified tech to check it for you.
Good luck, and remember that when the new flyback comes, the screen and focus controls will be set to minimum. The screen is the overall brightness of the picture and the focus is the sharpness.
As I said, the flyback comes with the 2 controls set to minimum. They are labeled SCREEN (on the bottom) and FOCUS (on the top). Turn the set on and tune to an active channel. Turn the SCREEN control up (clockwise) until you see a picture. Turn the FOCUS control up until the picture is nice and sharp. Go into the menu and set the brightness and contrast to minimum, and readjust the SCREEN until the picture is just barely visible. Put the contrast and brightness controls back to normal and your picture should be nice and normal. Tune in a channel with white letters on the screen and touch up the FOCUS, making the white letters nice and sharp. Let me know how it turns out.
Here is a little comment for YOU, Henry. The screen and focus leads have NOTHING to do with testing a flyback! The focus and screen wires can be completely shorted to ground in a standard TV and the flyback will still run. In the PTK195 chass, the flyback doesnt even HAVE a screen or focus wire! The 3 screen and focus wires originate in the focus block. The high voltage wire is the only one that matters, and it connects to the high voltage splitter, not a "focus module". When you stated you are a tech, I assumed that you would have had the common sense to test the high voltage splitter first. That is as basic as putting a new light bulb in a lamp that will not light up. When you stated that you were unable to locate the flyback, you were basically stating that you should be nowhere near the insides of a projection set, and I did not want to assist you. But you insisted, so I offered advice. On Sep. 3, you stated that the "new" flyback was working and you then had audio. That statement implies that the high voltage splitter is good. I assumed you correctly installed the flyback and correctly reattached the high voltage lead. The statements you made were misleading because YOU failed to install the flyback correctly! I cannot understand why people like you who have absolutely no experience in this field assume you are qualified to service your own set. I have been testing and replacing flyback transformers and high voltage splitters for over 25 years and you have NEVER tested or replaced one. You sent yourself on a wild goose chase by providing the wrong information! Next time, do not say you are a tech and try to provide more accurate information.
×
206 views
Usually answered in minutes!
I paid for your premium service for my tv problem. When can I expect a solution? Henry
I have a very limited schematic for my tv..Where is it located, and if possible part number? Does this solution addresses the problem of the tv trying to start a couple of times, and then shutting down?
Henry
Hey Mike...I understand that the problem may be in the Flyback Transformer, but like I said I have a very limited schematic. I can't locate the part I need to check...It's like being dropped in the middle of a rainforest, and asked to find my way home...Is this transformer on the main board? If you could give me a part number I may be able to find it, with what I have to work with...Thanks.....Henry
Thank You Mike for getting back to me...Like I stated I am a Tech, but not so much on tv's. I have with your help located the flyback transformer. I am just going to go ahead and replace it, and see what happens....Let you know.....Henry
I replaced the flyback transformer from a tv like mine..The tv turns on with audio, but no video. I guess I'm getting closer, because the set turns on. Any idea's on the video? Henry
As I stated I replaced the flyback with a used one. The sound came on, but the video didn't...Had nothing to do with the screen adjustment. I've since replaced the flyback with a new one..Now the symptom is no sound or picture, but the focus part of the guns glow in turn in the plastic part of the guns. The tv then turns off. Maybe some other short somewhere caused the transformer to go...Any suggestions? Henry
Here's a little comment for you Mike. To test for a shorted flyback transformer. First you disconnect the screen and focus leads, and place them where they can't touch something. Turn on the set and see if they are energized. If they are it's not the transformer. Then connect the screen lead and turn on the set, if it turns on that's good. Connect the focus lead and if the set turns off the focus module is most likely bad. The advice you gave me sent me on a wild goose chase....As it turns out the focus module was bad, and the transformer that I replaced for $68.00 was good. The set is up and running now no thanks to you. Next time don't act like you know it all.....Henry
If you knew what you were doing as a tech with your experience you should have known that the white high voltage block in the RCA very rarely goes bad. Don't worry about, being the bad tech that I am I figured it out all by myself...The set works perfectly. If I hurt your ego I'm sorry, but that's the way it goes.....Henry
×