I sold a laptop on ebay and now the guy is coming back to me saying it's faulty

I sold my erazor x7853 on ebay because i barely used it in the 6 months i owned it. The laptop was in perfect condition, no issues whatsoever. The guy received it on 28/03/2018 and said it was perfect, it's running perfectly and no issues which leads me to believe that his son who he bought the laptop for has somehow broken it.

today 30/03/2018 he has messaged me this: https://imgur.com/Biqatom

he says i wiped the laptop to try and clear a hard drive error.. which is stupid because i obviously used the windows 10 restart so all of my information was removed.. i've already paid my £200 fees and paid £40 to ship this to him.. what shall i do? shall i accept it has magically broken in the last 2 days and he should return it, or should i argue the fact the laptop was fine when i sent it and when he received it.

EDIT:

new message from him: https://imgur.com/a/BclqE

screenshot: https://imgur.com/a/ZMC2e

Submitted March 30, 2018 at 07:04PM by uniqueusername42O https://ift.tt/2GktXc8