Normally I wouldn't make a big deal about a WC system failure but the cause of this one made me say "What were they thinking!" I don't know whether this is a chronic problem or not but it seems like pretty stupid design anyway.
In moving my system home from college for the summer a kink worked itself into the line for my Northbridge block that effectively cut off flow to the block completely. I didn't notice it, by some miracle the system ran fine for several days, but it finally BSOD'd and I opened the thing up and found the kink. The block (DangerDen A8N block) looked like it got a little toasty but was otherwise fine so I went ahead and restarted the system.
Again it worked fine for a while until it BSOD'd (the famous "not less than or equal" error any experimenter gets familiar with) again. I just went over to try a restart this time but it was a no-go. Nothing, no power on at all.
I opened it up and found the mobo quite wet around the NB:
The waterblock looked to be in pretty bad shape so I pulled it apart:
Notice the nice ring formed by the block's O-ring. Next up is the warp on the plate:
And more detail on the O-ring indentation, measuring from the edge to the center (total depth) of the deformation:
My theory on the failure which I'm quite sure is correct is that without water the block heated up to the point that the block's top plastically deformed to the O-ring. Since the ring wasn't being squished anymore its ability to seal was badly damaged and with flow restored began to leak.
I was wondering, has this happened to anyone else? It just struck me as a pretty bad material choice for the application.