How to check the phase without access to cable of amp

[Ian986]

Hi all

I had a my cables hidden by a builder but not sure if they are in phase I thought my receiver would tell me if they where out of phase but I can't seem to find it on there is there any other way of finding out ? For the record I have onkyo TXNR 809

Thanks for your help

 

[RobinKidderminster]

auto setup will confirm phase. else use stereo and swap leads listening to base. else conrinuity meter or battery and bulb.