[Sainthunter]

I recently bought a Denon 'Personal Component System/AM-FM Stereo Receiver DRA-F100' unit from a charity shop - sold for spares or repair. Apart from a tuner issue the main fault is that after a while in standby mode it switches off completely from standby as though the mains has been switched off/a power cut.
Is there a back-up memory battery somewhere, I have tried leaving the unit powered up and switched on for at least 24 hours kidding myself that it will recharge the memory battery, if there is one?