Guitar Electronics Problems: Yamaha RGX-TT and Westone Pantera X390

[Nathan of Brainfertilizer Fame]

Similar problems.

On the Westone Pantera, there is almost no sound at all when plugged in. If I turn my amp to 9.8, the volume from the amp is now enough that I'm sure I'm not just hearing the guitar acoustically. But at any normal volume, it sounds like nothing at all.

How do I troubleshoot that without replacing every wire and basically rewiring every single element of the wiring harness?

On the RGX-TT, there is no crackle or cut-out in any of the pots or switches...but with settings that make a medium-loud distorted sound on any other guitar, on the RGX-TT it is a rather medium-soft sound, almost clean, sounding as if the tone were rolled off. And there is almost no tonal difference between the 2-5 positions...the only one that sounds different is the bridge (position 1).

Suggestions on troubleshooting?

[murkat]

input jack(s) [oxidation], chord.

[Nathan of Brainfertilizer Fame]

The problem isn't the guitar cord, but I'll check for oxidation.