when you say "mains" you are talking about the wall a.c. Correct? Assuming you literally sit/stand there and turn it off and then wait 10 or more seconds and turn it back on, then yes you have a cap/battery issue. I've looked through almost a dozen rs catalogs and can't find your receiver. What is the catalog number on the back?
The model number on the back of the STA-2250 is: 31-2095.
Could this be the catalog number?
Yes, a service manual would help, but couldn't locate one.What I really need to solve this one is a schematic.
I would think if there was a battery/cap for presets it would be located on the tuner board. I'll check my STA-2250 tonight.
Good deal :thmbsp:Hi,
today I fixed the problem without having the unoptainable service manual.:yippy:
In this receiver, there is no backup battery and no backup capacitor.
However, on the microprocessor board, there is, near the microprocessor, a 1000µF/10V elco.
When desoldering this elco, one of its wires was disconnected from the body (apparently by some chemical action).
Visually, nothing was giving a clue to this situation.
After replacing this elco, station memory is sustained.
On the same board, I replaced another 1000µF/10V elco, the value being decreased to about 100µF.
I also replaced some other elco's.
Visually, nothing seemed to be suspected. No bulging, no fluids escaping.
To me, it seems to be that the elco's in this receiver are not high quality types. It is my experience that quality Japanese audio gear does not suffer from bad elco's, even after 30 years!