iMac Screen Discoloration, Faulty Motherboard?

I took my 2017 27″ iMac to a shop yesterday to sell it and they offered me $345.00: the very same folks who stopped by my place two months ago to look it over and quoted me $1,557.00; but I decided to wait for my new 16″ MacBook Pro to arrive. That’s right – I’ve been waiting eight weeks! Anyhow, the reason the salesman gave for the disparity was that the iMac shut down unexpectedly when starting up and the edges of the screen are pink. He told me the logic board was about to die.

My previous iMac suffered from the same ugly discoloration. The 2017 iMac has been sluggish for as long as I can recall. In fact, I had to take it in almost two years ago to the day because one of the USB ports wasn’t recognized; and I’m not even sure if the logic board hasn’t already been replaced once, because the repair receipt is in Vietnamese. I took it to an Apple authorized service center this morning. Fortunately, it’s still covered under warranty until August (and I’ve been backing up with Time Machine for a while now). Whatever parts they need, they’ll have to order from Singapore, and as the shop will be closed over the Tet holiday, for sure it won’t be ready for pickup till next month. If they do replace the screen and can get it to run faster, I just might end up keeping it. My experience with Apple repair in Vietnam has in general been pretty awful though, so I’m not getting my hopes up.