sanyo ce32fwn problem

[aliris]

hi again..
I have this tv for a long time. It's been in the store for quite some times after developing a very annoying problem ..

model : sanyo ce32fwn
problem : the set will turn into standby mode after a period of time watching tv..(vary between 1 minutes to a couple of hours...but usually it takes longer before it switch off to standby mode if I leave it unplugged for long time)..the set will ok for a while after I turn it off and on again and it is just a matter of time before the fault reoccur..

any help is very much appreciated