Agree with SNS. Move quickly. a claim a week or more later is always suspeicious. I sold an amp. 2 weeks later they guy messages me that it won't power up. He had messaged me when he got it and said he would put it in service the next day so I was immediately suspicious. Not a paypal deal but they would be suspicious too.
Turned out to be operator error and I was able to help him figure it out. I'm only posting this because the 2 week delay make me immediately suspicious. Turns out he's 80 and needed help to move it.
So if you need help, have it lined up when the amp gets there.
Paypal would have stood by you if it was a black and white issue such as "doesn't work". Your claim is a probably interpreted by paypal as an opinion that it works but doesn't sound right. Frame your claim in the correct words.
Jerry