Weird amp problem: please help!!!

[JT23]

Hi, I bought a blue Kustom Coupe '36 with the twin 10 speakers off Ebay last year. The previous owner claimed he only changed the tubes & speakers; though, I always heard a rattle. Still, the thing worked amazing for many months. 

Then one day, I got shocked when I was setting our gear up. However, I just kinda assumed it was a gnarly old Sunn amp I had & thought nothing of it. At the next practice, my other guitarist used the Kustom & it was fine. Until the very end, it just like totally shorted out until there was no sound at all. Wiggling various cables got a low scratchy sound. 

So, anyway, this week, I took the back panel off & found a loose screw. Hoping it was the problem, I plugged in and now it cuts in & out like a bad wire (I tried various guitar cords & power cords). The real odd thing is as you tilt it forward, it cuts out less & less. In fact, when the speakers are completely face down, it seems to work fine. 

Any ideas on what could be the poblem? I'm really no gearhead so even just basic tips would be much appreciated. Thanks, John

[dubkitty]

the getting shocked and the loose screw could be totally unrelated to the output problem. check to see if the cable that connects the speakers to the amplifier chassis is defective. particularly check that it's not loose from one of the speaker terminals and shorting out.