Samsung tv/vcr combo (cbx1322)-power supply buzzes when plugged in. OK when switched on.

[Joe R.]

I have a Samsung tv/vcr combo, model number CBX1322, which makes a
buzzing noise from the power supply when it is plugged in. Noise goes
away when tv is switched on. Also, when a tape is put in, the unit
cycles on and off and tape will not function or even eject. The noise
is coming from around the T801 transformer. I believe it is either a
leaking Cap or a bad diode. Does anyone know of any known issues with
this board that would point me in the right direction? I do not have
a schematic, so I would just be guessing at which capacitor to start
with. Any help would be greatly appreciated.

Thanks!

 

[Sofie]

Joe R.
Your thinking is correct regarding the cause of the problem..... probably
faulty electrolytics in the SMPS circuitry..... the easiest way to find the
culprit(s) is to test them with an ESR METER..... lacking that,
substitution is the only other reliable testing method..... I would start
with the high uf / low volt units in the secondary and then check the
electrolytics in the primary side.

 

[RonKZ650]

I'm not familiar with your model, but if it's the standard Samsung, it was a
good set (for a combo). If it's the one I'm thinking of you've probably got 2
bad capacitors, a 470uf near the SMPS transformer on the TV chassis, and a 22uf
in the VCR power supply near it's SMPS transformer, (metal box in VCR).
Ron

 

[Patch]

I'm not familiar with your model, but if it's the standard Samsung, it was a
good set (for a combo). If it's the one I'm thinking of you've probably got 2
bad capacitors, a 470uf near the SMPS transformer on the TV chassis, and a 22uf
in the VCR power supply near it's SMPS transformer, (metal box in VCR).
Ron

As I recall, the 470 Mfd is C810.

 

[Joe R.]

As I recall, the 470 Mfd is C810.

Thank you very much! You were correct. The 470 Mfd (C810) capacitor
was the problem. I replace it and the noise is gone and the VCR is
operating correctly. I did not replace the 22 Mfd capacitor in the
VCR, but may replace it anyway as a precaution (since the I have it
opened up anyway).
Thanks again!
Joe R.