As title suggests my AV receiver turns itsef off. However it only does it when I first turn it on (from the remote). After about 5 seconds it turns itself back off. I press on again and then it stays on and works absolutely fine for as long as I use it. If I turn it off and on again once it's "warmed up" it doesn't do it. Only when it's been off for a while.

Have checked speaker cables not touching, etc and tried a factory reset. No luck. Not to do with heat as it only does it when it's cold and it doesn't get hot anyway. It started doing this recently, was fine for years.

Any ideas? Seems strange it only does it the once...  Unit is a Marantz SR6003

Cheers