I'm trying to fix a sansamp DI for someone at work. During a show, it just stopped working for him. We can get it to pass a signal with the battery in, but not with the power cord and the LED isn't going on at all. I opened it up and used a multimeter to confirm that it's getting 9V from the adapter... also from the battery. Other than that, I'm not sure what to check. I'm working on getting the board out of the box, but that is tough due to the construction. I have reflowed all of the solder in the meantime and can confirm that it's not a cold or cracked joint. Any other ideas?