MacOS – MacBook Pro Hardware & Software Issues under warranty

Your trip the Genius bar was too focused in my opinion. I suggest you make another appointment and lay out your case above, but this time, don't mention the memory tests, but that the problems showed up when you upgraded the RAM. Refer them to your old case number (tack this visit on as a follow-up).

Tell the Genius on hand that the problems still exist and that they need to do further testing. As it stands, your Mac is unusable. Additionally, tell them to make note that you have tried a fresh re-installation and it did nothing to help (don't mention that things ran fine for a day or too, stick to the current state of the system), which will rule out any software problems.

Ask them on what they suggest and follow it (no matter how annoying it may be). If it doesn't fix it, call them and do another follow-up. If they tested the RAM and it passes, then it might be the logicboard.

In any case, do not visit them with "the solution." Let them find it through there own testing. Clearly, the logs containing kernel panics and all the problems you list will support your case. Moreover, their internal testing tools are much more sophisticated than what you'll scrounge up on the net through 3rd party apps (they actually have in-house diagnostic utilities for these occasions).

I would highly recommend that you stop spending your time diagnosing the problem and let them do it for you. That's what they're there for.

If after everything is said and done, and they still can't pinpoint a problem, you will likely walk away with a new Mac. Just focus on the problems you are suffering from and leave the diagnostics to the Geniuses and technicians.

You may want to downgrade back to the 4 GB for now. And it's of note that replacing the RAM and the hard drive yourself do not void your warranty for that particular Mac model.

PS: You don't specify if you took your notebook to an Apple Store and spoke with a Genius or some Apple authorized repair centre. I would strongly encourage you to deal with Apple directly. They'll not only treat you better, but likely solve the problem with less headache. My advice is tailored to them; you are totally on your own should you choose a 3rd party repair shop. To galvanize the need to deal with Apple, let me put forth the following. I had a friend who purchased a Mac mini. There were strange problems during boot up where it would occasionally load the keyboard set-up assistant. The machine was also sluggish and exhibited other unusual anomalies in its day to day. We took it into an Apple Store and the Genius tried to reproduce the errors. He couldn't. He also expressly stated that minis never required repair or servicing. But with all that, he elected to replace the entire unit and gave my friend a new mini. Took it back to his place and it hummed, no more issues. I doubt he would have received the same treatment from a computer store authorized to service Macs. Deal with Apple direct; I cannot stress that enough.

Their evaluation & explanation sounds legitimate. I would assume that when the coffee was spilled it made it's way into the keyboard. If this is the case it's entirely reasonable to assume that it would make it's way through the keys and inside the top case, with the next component it reaches being the logic board.

In regards to your two questions:

1) Without seeing the Mac and only relying on my experience (see below) I can only make an assumption, but from the information given the list of parts does seem very likely. Yes, the logic board contains a majority of components for your Mac. The processor, GPU, SMC, some ports, etc are all located on this one major component. With the way I'm assuming the spill occurred the coffee wouldn't have made it to the SSD, which connects directly to the logic board, thanks to the SSD being located on the opposite side of the logic board. The only fault I see with their explanation is the speakers, I haven't replaced a Retina top case in a while but I could've sworn that the speakers are still separate components.

2) There's no way for them to tell you upfront if the parts are new or refurbished. Apple re-uses eligible (meaning not beyond economical repair) parts after a strict refurbishing process that includes individual testing of components. When technicians receive parts there is no distinguishing feature to know if it's used or newly manufactured. Honestly, the only way to be sure is if you request a part for a Mac that was just released, simply because there wouldn't have been time to collect used parts and put them through the refurbishing cycle. Either way in my experience I've never seen a trend of service (repair) parts being faulty. It DOES happen from time to time but I've never seen a trend of obviously refurbished parts leading to repeat repairs or premature failures. Apple's replacement parts do carry a 90 day warranty or take over the rest of your existing AppleCare warranty, whichever is a longer period.

Did the AASP mention a flat rate or depot repair to you? I haven't priced out the parts they mentioned in a while b considering the amount of damage that might be a little bit cheaper. Basically Apple offers tiered flat rate repairs for out of warranty situations. Since this is liquid damage it would likely be a tier 4, the highest of them, but it might still be a little cheaper. Might be something to ask them about.

Source - I worked as a Genius for several years, as an in-store and onsite AppleCare certified technician for several years and have dealt with AppleCare extensively on both sides (as a technician and as a representative for an enterprise customer) for several years. I've repaired well over 1000 MacBooks, around 1000 iMacs, several hundred MacBook Pros/Airs and a couple hundred Mac minis and Mac Pros. Everything from in warranty failures to severe fire and liquid damage.