Hi have this problem with CRT tv model no: RC-4120PS, powersupply is whining.No high voltage ,no scr. voltage however the power LED comes on with the whining noise.There's also no voltage going to the Horizontal aswell as the vertical yoke.Have traced the whining noise to the high freq transformer not lopt.
The voltage going to the collector of the HOT is correct 135V but drops to 93V when I press the power switch, there's also otputs on two 25v, 470uF ecaps. of 10V each.
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THAT TV HAS WHAT IS CALLED A COLOR WHEEL WHICH SPINS AT VERY HIGH RPMS AND CAN MAKE HIGH PITCHED WHINING/GRINDING NOISES IF A FAN WAS BAD THE TV WOULD SHUTDOWN AND THE SOUND WOULD BE MORE DULL SOUNDING.
The colors wheel is dead.That why,u hearing high pitched whining sound.The colors wheel is spinning off of is motor axis and grinding it sides walls,that where the high pitched whining sound came from.Hire a tv Tech. for the colors wheel changing,because it requiring to take out alots of the machanicals parts itself,before u can come to the colors wheel itself to change it.
If it sounds almost like a whistling sound but high frequency it can be many different causes.My two first "suspects"would be the powersupply.Usually a transistor.Then at the High Voltage area that supplies the screens brightness.It can be lots of things.It can be the High Voltage transformer that has a dry joint.Best is to take it to repair shop so they can open and do few tests.
First, you will want to isolate the problem. Is it feedback from an AC outlet you have it plugged into? Is it a recent noise that just started with no changes to Tv or its environment, then you may want to consider that a circuit is going and decide if it is worth repairing, You should find that type of fix at a shop for under $100
This might be from the IHVT (Integrated High Voltage Transformer), or more specifically a short in the IHVT causing it to arc, producing the high pitched whine, you are hearing. Take the back off of the TV and try to detect where the sound is coming from, more then likely you will notice it coming from the section that contains a large component with a large red cable coming from it, to the top of the CRT (picture tube). Replace the IHVT (with the exact same model) if it is bad.
If it weren't for the high pitch whining noise. I would say it probably is an internal fuse inside the chasis. It is rated at 1.5 to 2.0 amps. With the whining noise it sounds like a trouble shooting bench
job. Problems occur when a electrical/electronics device is turned on and turned off. Inrush voltage,
when it is turned on, can go up to three times more than normal. This also happens at turn off. Solid state components usually fail at this time. I don't feel that this is a problem that can be fixed in the home.---BBB
You have a problem is in your horizontal section which also is part of your power supply. The high pitched whine is from the Intergrated High voltage transformer (also called the flyback transformer). This sound occurs when the freuency of the transformer changes and or the voltage gets too high. The click occurs as a result of the drawing of excessive current by the HOT Horizontal output transistor. This is repairable, but requires the correct equipment and a schematic.