just got fender blue jr off ebay
and it turns on fine
but when i hook up my guitar it doesnt work

what is up?

thanks guys
how would i know if it was damaged

just lookin at it, i dotn think anythings wrong with it
ok when i hook up guitar to amp it doesnt play
whe i hook up my guitar through boss od-20
and then to amp
it plays
but its so low
andwhen i shut pedal off there is no sound

some one help pleaes
There's not really any effective way of diagnosing "it doesn't work" over the internet.
My best guess is the preamp tube is shot, I'd start by replacing that. Replacing the power tubes is a good idea too. The input jack is a possible suspect but not likely since it works with a pedal and isn't intermittent.
Stop bumping your thread. It's been half an hour. Have you tried changing tubes? Checked cables? Volume controls? Guitar wiring?