Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Hello I have a crate gfx 120 amp. Im getting no sound out of it when I plug in an guiter. I can unplug the guitar and touch the end of the cord and still I dont get any signal noise. When I plug a cord in the external speaker jack and touch the end of it, I get a low voltage shock through my fingers. Does any one know what my probelm could be? os steps on troble shooting the probelm. Thanks for the help adv

Start by plugging a guitar cord into the effects loop return, do you get sound?
Plug it from loop out to loop in, does the preamp work now?

Hello JM, Thanks for responding! This amp has two channels. On the front of the amp is where the external speaker jack is and a foot switch jack. It has 3 effects knob(chrous,delay and a reverb).Whats wierd about the amp is It doesnt have a effects loop on it.find it strange that I would get shocked from just plugging in a cord to the ext. speaker jack.I thought that it could be a earth ground jumping some whereThe kid that owns it said he tried to plug a 4 10 cab to the ext. speaker and after that it went down hill from there. I notice that the in put jack seem to be week just by plugging in the cord to it or it felt that way to me. Im going to do a continutity test on it to see what happens! Do you have anymore suggestions? Thanks adv

I have a better plan, test the speaker first.  If you get a shock from the external speaker jack, that pretty much means the amp is putting output signal there.  Test your speaker by touching the terminals of a 9 volt battery to the speaker terminals briefly.  A good speaker will pop or thump when you touch.  A dead speaker will just sit there.   And the wire/cord between amp and speaker could also be defective.