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onkyo T401 fm tuner

I've bought an old onkyo fm stereo tuner T401 on e-bay. It works beautifully except that it does not rremember the push-button tuner settings when it is switched off and later on again.

The owner's manual says the memory shouldnormall last for several weeks butless under humid conditions. This suggests that the standbypower comes from a capacitor.

I can't find the capacitor, and I haven't been able to get any technical information such as circuit diagram or parts placement -- not from Sams nor from e-bay.

I'd be grateful for any help someone can give me on locating the standby power source. Maybe I can replace it or simply add a samll battery if I could know where to connect it.

Mel Levine

Reply to
lilolevine
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If it is capacitor backed, it will be one of the Supacap or Goldcap types. They are usually green and about the size of two calculator batteries stacked on top of each other. The value is usually around 0.5F at 5.5v working. You would normally expect it to be located on the front pcb, near to the system control processor.

Arfa

Reply to
Arfa Daily

Recently went through this with my T4500. The memory capacitor was bad. Mine was on the front panel board. It may have been under the display. Got a replacement from Mouser for very few $

Regards,

Reply to
Bob La Rocca

It is C754, a 0.1F (Farad) 5.5 volt capacitor located on the front panel circuit board, underneath the display tube, next to the microprocessor.

Mark Z.

Reply to
Mark D. Zacharias

Many thanks fo rthe prompt help you all gave me on my memory capacitor problem. Your advice was right on the money. I could never have found the guilty capacitor on my own!

I replaced the capacitor with some aaa dry cells and included a diode to keep the receiver from trying to charge them. Working fine now.

Gratefully, Mel

Reply to
lilolevine

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