Bought a used june 2012 RMPB. But the mac had 2 issues. 1) it had image retention (lg screen) and 2) during normal mac osx usage it kept frozing and restarting says it will restart in 10sec or something. And at one time when it rebooted it gave me 3 beeps. So I took it to an apple service center (i'm in korea and there is no official apple shop. Just apple certified retail service center)and told them those symptoms. The guy said 3 beeps is ram issue so will have to exchange the entire mb since ram is soldered. When I got it back it had another lg screen but no retention so I said ok. But after 30min of usage or so it kept freezing again. Then after me trying to recover and install a fresh os it just froze so I couldnt do anything. I took it again and they apologized and said they will take a look and fix it. a few days later they told me this time it was ssd that went wrong and they said they replaced the ssd. but after taking it home its freezing again and now giving me the attached screenshot. Image distortion. what could be the actual issue here? Did anyone have the same issue? Tldr: this whole freezing and rebooting issue could this be a motherboard issue or ssd or graphic card?