Entertainment Center: TVs, Stereos, VCRs and DVDs - GE TV/VCR Squeal

I have a 1994 GE TV/VCR combo that has a high pitched squeal when its off. Doesn't seem to matter if the tape is in or out, or where the TV is positioned in the room. The squeal goes away when its turned on. Any ideas?
Chassis# K50MVR08
Model# 13TVR01
Serial# 402210729

TSTorm317, Sound like the switch mode transformer(or standby transformer) in the power supply is running slightly off frequency due to leaky electrolytic capacitors on the secondary side of this transformer. This a commom problem with that samsung power supply module that was used with that vcr(should be a samsung). When those capacitors become leaky and can no longer hold the voltage that is needed to maintain the smooth operation of that transformer in standby mode, the transformer will start to squeal. Standby mode is when the power supply is at 60% output(The percentages may be a little off, it's been awhile) which is enough to keep the micro-computer, memory, clock and running. When you push the power button, the micro-computer switches the power supply from standby to 100%, which allows the other circuits to begin working. Their is a rebuild kit for that module, or you can replace it with a new one. Either one is not that expensive since that is an older combo unit. Let me no which way you plan to go.


Fred:)

Where would I get a rebuild kit?

TSTorm317, You need to remove the back cover and tell me if their is a small retangular circuit board to the left of the vcr. This is your sweep/power supply board. Their should be a flyback transformer(black thing with a large red wire coming out top going to top of picture tube) and up toward the front of the board you should see a small transformer with electrolytic capacitors (black cylindrical things mounted to the circuit board around the this transformer. This is your switch-mode transformer. Or if their is a one piece circuit board.



Post back and let me know what you found.




Fred:)

Fred, there is a "large" circuit board (about 1' square) to the left of the picture tube mounted vertically above the VCR. I can see the flyback transformer with the red wire, going to the tube and yes there is a small black transformer towards the front of the TV. The only other circuit board is a small one (about 3" square) attached to the back of the picture tube

TSTorm317, Just as I thought, one piece. Plug the television in and make sure you have the right transformer. Also, you will need a 40watt soldering iron, solderwick and 60/40 solder(you may need a capacitor checker/tester meter but, hold off on that for right now), trying to find a schematic on that unit so i can tell you which capacitors to change. Is that circuit board a bone color (light beige) or off brown?



Fred:)

Fred, the circuit board is brownish in color.

Fred - Here's a picture of the circuit board. The straw points to where the squeal is coming from....

TSTorm317, Looking at the photo that power supply area of the board looks discolored due to heat build-up from that transformer squealing and from the driver circuit (that I.C. thats encased in black epoxy) right below where the straw is pointing. Check that small capacitor in front of the voltage reg. transistor(three leg transistor mounted to large heatsink) and the one just to the right of the transformer. I'm leaning toward that driver I.C. module. Once the schematic comes in I can get a better look at the I.C. 's layout.




Fred:)

Your beyond me here Fred. Is it worth taking to someone to fix? What do you think would be a fair price? Considering the cost of replacing new - I wouldn't want to pay a lot. I can put up with the squeal by covering it with backround noice like the radio.