How to check if CPU cooler has died

[Jt00]

My system has been slowing down recently, and up until today I thought it might be caused by a virus or malware. I reduced the frequency on my overclock just in case that was causing the issue. Today however, I installed HWMonitor Pro after researching the problem online and seeing that help someone else find the cause of their problem.
Upon running it I saw that every core of my CPU was at 105 C. I immediately shut down my computer and have been letting it cool off since then. I don't know why I didn't think earlier to check CPU temps, but I didn't. I'll be lucky if the processor isn't permanently damaged.
I took off the side panel for my computer and felt the cooler, which is a Cooler Master Seidon 120V cooler. The radiator is about room temperature, but the block on top of the CPU is extremely hot. Feeling along the hose that connects the radiator and pump block, it gets progressively hotter as I move from the radiator to the block. This leads me to believe that the cooling fluid is not being pumped away from the CPU, letting it overheat.
Is there a way I can confirm whether or not the pump is bad before buying a new cooler?

 

[isaac4643]

so its a AIO cooler...?

 

[Dunlop0078]

Can you hear the pump? They make noise, if its doing something it should be making some audible noise. The only other way you're going to get temps like that with a water cooler is if you used no thermal paste at all, or the block is not mounted properly and barely touching the cpu. But since you said the block was hot it must be transferring heat so I doubt thats the issue. I would assume the pump is dead, or not plugged in I'm giving you the benefit of the doubt on that one lol.

 

[Jt00]

Yes, specifically a Cooler Master Seidon 120V.
It's difficult to hear anything but the fans while the computer is running, but I'll see if I can hear the pump. I definitely used thermal paste and mounted it correctly, but this cooler has been on there for over 2 years now, so I wouldn't be surprised if the pump has gone out on it.

 

[Jt00]

Well, I've narrowed the problem down to two possibilities, after taking the case completely apart, cleaning out an ungodly amount of dust from the radiator, case fans, and case itself, cleaning off the contact between the water block and CPU, reapplying thermal paste, and restarting:
1. The pump is pretty much completely dead, but still gets enough power to turn weakly and make some noise, which is only audible with all case fans and GPU disconnected, or
2. Enough coolant has evaporated from the system (apparently that happens in closed loop coolers as well as custom builds) that the pump, though operational, can't move coolant through the system.
Either way, the bottom line is that the CPU pretty much sits there boiling under the load of doing any task, with temps hovering around 100 C. I guess I'll be in the market for a new water cooler then.
The pumps on these aren't replaceable, are they? I'm way beyond warranty, so I wouldn't mind doing any kind of work on the cooler to try to get it working again.