I need help, desperately.
I have recently put up my modified Stax SRM-T1 for sale. I sold it a bit more than a week ago to another head-fi user, who contacted me via PM. Before the transaction I described everything exactly as it was and provided him with all the necessary pictures. I packaged the amp safely (double carton, plenty of blister pack...) and sent it to him. Shipment was tracked and insured.
He received the amp on 25th of this month, giving me positive feedback for it and added in a private comment that the amp worked well, but lacked a bit of dynamics.
Three days later he claimed that the amp emitted a loud noise and one of the channels is undulating. Therefore he thinks that the amp is not functional at all. I told him that it was fully functional when it left and that nothing went wrong during transport, as otherwise the package or the amp itself would have arrived in a damaged state.
That didn't matter to him. He started talking about sending it back to me. I said that I don't have a return policy as a private seller, but I will help him solve the problem nevertheless. I also recommended to write about in the Stax thread. After a few messages he said that theres an audio shop who could solve the problem for him, but it would cost about 100€. I replied that that's bad, but I hope that it's not complicated and the problem be resolved soon.
He then replied, and I quote 1 on 1:
"Bad indeed, as you don't have the basic correctness to offer to pay for repair."
In the meantime he had opened a paypal dispute, demanding a full refund because of "internal damage" of the amp. I couldn't even reply to it properly, as everything escalated to a claim minutes later.
I provided PayPal with all the files I could offer (pictures of the amp - especially the inside, our conversation on head-fi etc., shipment confirmation and so on) so that the PayPal specialist can look into that. Then I thought "Hey, he gave me positive feedback and added a comment to it that everything was ok. I should make a screenshot and a copy of that and add that that to the files...". So I went to the feedback page on head-fi and... the feedback was gone. He deleted it. I then immediately contacted Head-fi via the support form and asked if someone could please provide me with the feedback that he deleted, saying that it was important because of the ongoing PayPal claim.
And now I don't know what to do. Basically he could just go to the audio shop, let them confirm in writing that the amp is broken (even if that statement might be fake or half correct or whatever) and add that as evidence. Then I'm probably screwed.
I have no idea of what went wrong with the amp, and I can't imagine how I can be held responsible for the problem he is describing. It worked when it was still at my home, I packaged it very well and the shipment arrived without any damage at this location.
What on earth should I do now...