Dead radio presets

burdette

Not sure where this post would fit, so I'm sticking it here.

I have an old Onkyo TX-84 receiver (new around 1988).

The unit will no longer hold radio presets when it's turned off. It remains plugged in, just powered down.

I took the cover off and looked for any sort of battery - couldn't find anything.

I sent Onkyo an email but haven't heard back yet.

Thought someone here might know something about this... Thanks.

Joe08867

I would bet there is a battery mounted on the circuit board somewhere. Like they do in PC's. I have the same problem with an old Onkyo Receiver I have. I never really went crazy looking for a solution but I can look on mine to see.

Actually looking up the TX-84 I think we might have the same receiver.

billbillw

This is a common problem with gear that is 20+ years old. Most receivers and tuners from that era use a 'super capacitor' to store the memory presets. Over time, it fails to hold the charge. You'd need the service manual to figure out which one to swap out, or, if you are lucky, you can identify it by looking inside. It would be on the board where the 'brain' is. Typically it would be a short, fat cap, probably a different color than all the rest.

Something like this:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=P12914-ND

Note: You will have to figure out the exact value and match it up. Don't be confused by the microfarad vs farad. uF vs F. Most caps are spec'd as uF, the super caps are in F.

burdette

billbillw wrote: »

Most receivers and tuners from that era use a 'super capacitor' to store the memory presets. Over time, it fails to hold the charge.

Thanks for the information, guys. I had a suspicion it was an actual circuit component when I couldn't find a battery.

As of now this receiver has been "loaned" to my 11yo daughter for her room. I don't think I'll be swapping out caps, as she rarely listens to the radio.

Thanks again for the quick, helpful replies.