Hello everyone, I bought a used JVM401H the other day and absolutely love it but have some concerns and questions and could use some feedback. This is my 1st experience with the JVM and the amp sounds and feels amazing but here are my questions and concerns: 1) I can not get the serial/parallel fx loop to work. Tried 2 different pedals in the loop, different cables, diff dry/wet mix settings...nothing. If I take a patch cable and hook it up to the send return I get sound. If I take 2 cables and stick one in the send and the other in the return (with no pedal inserted) and touch the 2 cables together it makes no noise. It's like the FX loop isn't even on or in the amp. 2) The seller bought it used and said there were no mods done but can you more experienced guys look at the attached pics and tell me if it looks stock? 3) Amp didn't come with the foot switch and is missing the back panel. There is a lot of rust too on the chassis which makes me wonder how well this was taken care of (I also have no idea if the MIDI works since I do not have the footswitch). Since the FX loop doesn't work the seller said he would take it back and give me a full refund. Or he said he would give me a partial refund to pay for a tech to fix the FX loop. I can buy another used one that is in better condition, with a foot switch and back mesh panel with JJ tubes instead of the Mullards but I am worried that maybe this one may sound and feel better because there were mods done or maybe the Mullards are better than the JJ's etc. I don't have any point of reference since this is my first JVM. If its bone stock I think I'll return it but if you guys think otherwise let me know. Thanks!