I went down to a local guitar shop today and made a trade of my old crate amp and an old fender and got a used crate half-stack... It has a VC-50H head, and VC-410E cab. I load it up, turn it on, and let it set and warm up for about 5 minutes since it's all tube. The problem is.. I can't get any sound to come out of it unless I turn standby on. After I do this, if I start playing it, after a little while it will kinda cut-out and get louder and distorted. It will do this on and off randomly. I dont know what the problem is... The guy at the guitar shop said the input might need replaced cause it gets bothered by the vibrations from the cab... but I have been playing it real real quiet. I dont know if I should just take it back and get my money on Monday or what. Has anyone here ever had this problem or heard of it? Thanks for any help at all.. -Mike

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PS.
Here are reviews etc on the head... I couldn't find anything on the cab...

http://harmony-central.com/Guitar/Data/Crate/VC50H-01.html