I would have said that's a grounding issue, therefore meaning PSU. I would seriously change out the PSU, tell him to not use his PC until he can change out PSU. 520W would usually be enough for a system like this but generally, it's good practice to use a better PSU. I've had a similar unit kill two cards, it was only when I replaced the PSU that I fixed several issues at once. Although the PSU may not indicate that it's failing, it could still be dying on you.