Sharp VCR Power Supply Schematic

Nov 28, 2007 4 Replies
C

I have a Sharp VC-A66U VCR with a dead switching power supply. I have replaced the chopper transistor and the fuse. It's no longer dead, but it does not regulate. Can anyone tell me what the output voltages should be? It uses



a Zebra M67209 hybrid IC for the PWM controller. I'm looking for the datasheet on this IC as well as the schematic for the VCR or at least the power supply portion. I've not been able to find anything with Google. Can anyone point me to a schematic for this or a similar Sharp VCR? Please reply to newsgroup. TIA.



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E

Does it use an opto-isolator for the feedback ? Hint, look for one bridging the

6mm gap on the pcb between primary and secondary parts.

Check that the opto's functioning and check the components driving it.

Graham

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A

Have you tried it working into a load ? In general, it's pretty unusual for switchers to fail to regulate, especially if the original fault was primary-side.

Arfa

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F

On Tue, 27 Nov 2007 23:38:18 -0600, CL put finger to keyboard and composed:

It appears from the following VCR fault database that C913 (47uF/16V) may be the root cause of your problem.

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Model Fault Remedy

--------------------------------------------------------------------- VCA45U(VCH75U) Dead C913 (47/16v), Q901(2SC4273) & IC901 (M67209) VCH75U(VCH45U) Dead C913, 47/16v; Q901, 2SC4273 & IC901 M67209

FWIW, these Sharp models appear to use the same chip: VCA63 VCA36 VCA40G

My parts supplier's database suggests that the M67209 is equivalent to a 95KUCH0078ZZ.

- Franc Zabkar

Please remove one 'i' from my address when replying by email.
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