any stereo cable should work but i believe the planet waves on or the stock one from line 6 is a snuger fit if you test the cable for continuity and it passes it could be a bad plug inthe guitar or the xps
Hmmm . . . I'm actually having a similar issue with my VAX 300. My cat ate the Planet Waves TRS cable that came with my VAX. I noticed that it had expanders on the barrel to insure a snug fit in the jack.
Now, it works fine with the VDI, and on batteries, but I have intermittent power problems with a standard TRS cable. Maybe the plug isn't fitting in snugly enough?
They have the Planet Waves cable in the Line 6 store. Maybe I'll try ordering a new one!