Hi all,
 
I'll start off by saying that I know I've screwed something up here, I'm just looking for some advice on information I can gather in order to determine what I need to do to move forward. So I recently (in the last 3 months) built a new PC with a hardline loop with an RTX 2080 Ti FTW 3 Ultra Hydro Copper card (P/N 11G-P4-2489-KR) and today while I was playing Escape From Tarkov, my computer shutdown unexpectedly and when I looked over at my computer, the tubing was drooping. Obviously things were way too hot, but I'm not sure if it was an airflow issue, or if my pump stopped when my computer last went to sleep and didn't start back up when I woke it. After hours of troubleshooting, I've found out that almost certainly it is my GPU that is dead. Without the GPU plugged into a PCI-e slot (I tried all of them on my motherboard as well as on a different computer that I know has working PCI-e slots as well as a different GPU in my new rig's slots), my computer will turn on and begin starting up. When I put my card in the GPU slot with or without the additional PCI power connectors in I get no lights, no radiator fan spin, nothing to indicate that there is even power going to my computer.
 
Is there any additional troubleshooting that I could/need to do in order to more specifically identify the problem? Reviewing my warranty, it doesn't appear that this would be covered since the cause of death is definitely on me, do I have any potential options for repair, or am I just SOL here?

GPU's have built in thermal protection to turn the card off if it gets too hot to prevent damage. Sounds like the card just died for some other reason. You can still rma it.

Yeah I was thinking that should be the case with the card turning off if it gets too hot, but wasn't positive. Thanks, I'll start the process of RMA-ing it and see how it goes.

Assuming that you are using PETG, in a well built loop 10/12mm tubes will start to deform and droop at fluid temps as low as 40C. If the tubes are sagging you need to find the source of the overheating issue. Also I would recommend replacing all of the tubes... you blow a tube when the loop is running and chances are you will lose everything in the case depending on where the tube is at. As far as the GPU being toast... I guess anything is possible, but thermal protection in theory should have prevented damage to the GPU. You can always try an RMA the card however if it is less than 30 days old and purchased in the US I would suggest returning the card and purchasing a new one.
 
Top Tip: 
Do not build a liquid cooled loop without a temp sensor in the fluid with some type of active monitoring in place. 

That's correct, I am using PETG. I've already started putting together a new loop but wanted to see if I was going to have to plan around a potentially different video card before I finished that up.
I actually do have a fluid temp sensor, I really don't know how I could've missed temps going up super high. As far as the overheating, as soon as I can get my system back up and running that's my #1 priority, but currently without the GPU which was a significant source of the generated heat I'm a bit  stumped. When I first built the system in November I had some issues with the BIOS recognizing the pump header especially after a wake when which is why I put that as a possibility for the starting cause, but that hasn't happened since I resolved the initial issue.
Thanks for the advice!
 
ETA: I didn't know about the 40C thing, though. I don't think my fluid generally gets that high, but what I'd read was that PETG starts to become malleable around 60C, so I really only paid attention to keeping it below that. In any event I'll be doing what I can to lower temps in general even aside from whatever is causing the current overheating issue, but I will definitely be keeping that new number in mind for those improvements.

PETG won't show signs until the 60c area just like soft tubing which is around 65c which by than the tubings are compromised.  40c is fine.  Sounds like you hit VERY high water temps to see the hard tubing compromised which says something went wrong with your loop which needs to be investigated and monitored at all times till the issue is fixed and for future reference, you'll want to add some type of alarms along with water temps. 

List of your loop including pumps, fans, rads, blocks, etc. and some images would help.
 
Not to overcomplicate things for ya but if you're up for the challenge, you could use something like this instead of MB headers and run the alarms in a software, etc.

GTXJackBauer
PETG won't show signs until the 60c area just like soft tubing which is around 65c which by than the tubings are compromised.  40c is fine.  Sounds like you hit VERY high water temps to see the hard tubing compromised which says something went wrong with your loop which needs to be investigated and monitored at all times till the issue is fixed and for future reference, you'll want to add some type of alarms along with water temps. 

List of your loop including pumps, fans, rads, blocks, etc. and some images would help.
 
Not to overcomplicate things for ya but if you're up for the challenge, you could use something like this instead of MB headers and run the alarms in a software, etc.

Yeah about that... according to EKWB 40C, they even have it posted on there site. Talked with EKJake and got confirmation on that as well. 

That's crazy if EK says their tubing is 40c.  A general google search will state 62c but I guess EK's tubing isn't as strong. Some of us will hit 40c water temps in the summer days with AC on or at least with more than 1 GPU.  I used to hit 42c on dual 780s for a long time with no issue since I used soft tubing.  Still using the same tubing as we speak.

The loop is the video card mentioned, an i9 9900k, and a 360 thick rad from EK (XE series I think?) all in a PC-O11 Dynamic case with the distro block built for the case. Order is pump (in the distro block) to GPU, back to distro, CPU, back to distro, then rad. All EK blocks, tubing, and fittings other than the distro plate made by bitspower, and the block on the card is EVGA obviously. I know the single 360 rad is pushing it for the hardware it's cooling, but my temps have always been low, I'm not overclocking or pushing my computer much at all at the moment, and the airflow is good. The plan is to redo the loop once I can figure out how to fit another rad in there, but with the way my temps have been outside of this specific instance (this computer has gotten a lot of use in the 3 months I've had it running), I haven't wanted to make a bunch of major modifications until the weather warms up (midwest ambient temps are pretty low this time of year). Fluid is EK coolant, no coloring.
 
I added a picture that I believe was taken right after leak testing was finished and I booted it up for the first time.