Posted 26 September 2015 - 08:05 PM
I did not have that problem on my 300. The 300 & 600 were pretty much the same animal, except the 600 had a tremolo, where my 300 does not. Both the 300 and 600 had the unitized metal box some called the "coffin" under the faceplate that holds the electronics of the guitar -- different from the 500 & 700 models.
Anyway, I remember discussions on the L6 forums of people having problems with that "coffin" box - either it not being grounded properly or a conductor inside coming loose and grounding itself on the inside of that box.... Try searching for the discussions of that issue on both the 300 & 600 Variaxes. I know that the Line 6 archives have had spotty availability from that time period, but you can try, and also try googling the internet, to see if any other forums had discussions of such problems, and their solutions.
If you know the risks and have no problem working inside your instrument, then you can try taking a look & see if anything looks amiss. Other than that, it's gonna be Line 6 repair....
All your choice.
Line 6 Gear - Variax 300; JTV-59, JTV-69S, Pocket-POD, POD XTL - (RIP), POD X3L, HD500, HD500X, HELIX
1966 Gretsch Country Gent, 1973 Fender Tele Deluxe, 1978 Strat, 2017 Tele Elite, Epiphone LP Classic, Epiphone Special with P-90's
Gigging Amps: Alto TS210, Alto TS112A, Quilter Tone Block 200, Crown XL1000; Yorkville NX35 Speakers