I just replaced the flyback transformer on my RCA D52W19 TV. The picture displays, but now I get horizontal scan lines at the top of the screen, and every 5 - 6 seconds the screen "jumps" to the side, or it flickers similar to a CRT when it degausses. As far as I can tell, all connections are solid. Any idea what could be causing this?
I'm not sure if it could be a bad connection on the flyback, or the new part is faulty, or if something else went bad when the original flyback burned up. Any help would be appreciated...I'd like to fix this myself if at all possible.
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Check and replace damaged component/s at its horizontal scan output section circuit. Check the LOT (Line Output Transformer) too for damage. Replace the horizontal scan output transistor. Check the input voltage to LOT. If the voltage is absent check the feeder resistor; if any. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. http://electronicshelponline.blogspot.com/
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Along with the flyback transofrmer, its horizontal output transistor also must be replaced. I don't know whether you have replaced it or not. If not, replace it too. It can be located very near to the flyback transformer, a three terminal component, black in colour, usually screwed to a metal heatsink. Then switch on the TV and measure the video output voltage at the video output card pluged directly to the picture tube neck. The collector of the video aoutput transistors must come around 145VDC. If it also is there, advance the screen control on the flyback transformer to get a raster. If that voltage is not there, it means that the flyback transformer is not working, and horizontal oscillator stage should be checked for oscillation, check the lined drive transformer for its primary winding open, Check the entire horizontal oscillator section. The collector point of the line drive transistor, the transistor that drives the line drive transformer, a small transformer soldered diretly to the printed circuit board; should be checked with frequency meter. The frequency at that point should come around 15525HZ approx: OK.
If there is no picture and 3 vertical lines in the center of the screen, stop. Turn off TV. You have no horizontal deflection happening. Lines will burn into crts and be permanently visible after repair.
No horizontal deflection is caused by Horizontal sweep circuit failure, maybe flyback transformer and associated components. More than a simple do-it-yourself repair.
Cold solder joints on the flyback transformer circuit board - probably because RCA used feed-thru steel rivets on their boards. Re-solder the connections using a good solder flux for clean solder joints and this will fix prob. The joints with the dull, pitted finish are the problem joints. S. Hampton
Hello Chris this problem is coming from your high voltage circuit which consist of the flyback transformer and the horizontal output circuit, the most common problem when it is acting this way would be bad soldering on the flyback transformer or defective transformer but keep in mind it can also be caused by the horizontal circuit or a faulty lamp as well can cause this problem, what i would recommend is to have a tech come out to service your tv set this should not be an expensive repair since most of the time it is just bad soldering on the flyback thank you hope this helps.
This transformer does not come with the hv lead,if the arch is coming from the side of the transformer,cut the side of the plug were it goes into the transformer and the lead will come out,there is no voltage stored on the hv lead after the set is unpluged for a few min.,the transformer you can get at any rca repair center.
The picture tube can hold a charge.with a jumper connect one end to the ground wire around the picture tub. attach the other end to a screw driver and push it under the red cap on the picture tub. that will discharge it.. Remove the transformer from the board by disordering all connections. Insert the new fly and solder. from the old transformer follow the two leads on the side to the screen board at the picture tube. one at a time connect the new transformer leads to the socket and board. part number for the FBT 259296 $50.39 from www.theparts store
It looks like the squeal or high pitch is produced by the flyback part # 257805. Also check the the secondary side of the power supply for around 130VDC if that voltage is found to be lower than 120VDC I would suggest to replace CP80 with a 100 mfd@250 vdc. Part # 218374
Globalsemi.com has these parts, for the flyback transformer just type in search for FLY-391, this one is cheaper than the genuine(257805) fly back.