This Board has been so helpful in solving other problems related to my 300 and 500, I'd thought I'd give this one a try. I'm powering my 300 with batteries--fresh ones. When I plug in the 1/4" jack there is a about a 5 second delay until the guitar seems to 'notice' that the jack is in there and it powers itself. Until that, no audio output. The 5 second delay wouldn't be so bad, but when I haven't played the guitar for awhile (say, overnight), the delay is much longer. To the point where sometimes I can't get it to start up (i.e., no audio output) until I unplug the 1/4" jack from my guitar to my pedalboard and plug the guitar directly into my amp. That seems to 'wake up' the 300. Then I can go back to connecting the guitar through the pedalboard and it works fine again (fine, but with a 5 second delay until it starts up). I have tried powering with the XPS box and no real difference. It actually seems to work better with batteries. I've scanned the discussions and can't find any posts with quite the same problem. Anyone out there have any ideas?  Thanks much.

BTW, in full disclosure, I should add that I replaced the standard LR Baggs piezos with GraphTechs. However, that part works fine. I don't think the GraphTechs have a role in this problem.