|Fig. 1. EHX Holy Grail Reverb, original enclosure.|
Visual inspection revealed nothing, except a few solder joints that looked sloppier than stock. I plugged it in to verify that it didn't work, and indeed it didn't. Oddly, though, when I turned the knob, I briefly heard a reverb-soaked pop/clank sound, almost like when you jar an amp with the spring unit in it. Thinking something must be loose, I left it on and poked every wire and component that was big enough to poke with no luck.
|Fig. 2. Everything looked good on both sides of the board, except for the three solder joints on the upper left of the board, which looked like they had been redone. That turned out to be irrelevant.|
I plugged it in and it worked. I fiddled with all the knobs and plugs like before and it still works. It must have had some gunk in the pot. It turned out to be less complicated than I expected.