I have a relatively new custom-built machine [September 2020] that has a triple cooling circuit [one loop for CPU and one each for a pair of GPUs].

Machine has been running perfectly since built.

This evening I powered it up and although I got no audible alarms, although there was no sign of distress from either CPU or GPU monitoring software, I caught a trace of what I thought smelled like an over-heated electrical component.

I checked via Aquasuite immediately, at which point I spotted that the 12v supply to my "GPU #2" pump was showing 0v. Interestingly, the pump is running, the GPU temperature remains at room ambient and everything seems OK.

From a physical perspective the machine has not been disturbed, so I think an accidentally dislodged cable is highly unlikely.

Very interested to learn of other users' experience and any clues as to what this might be? The obvious thing will be to check voltages on the feed and from that try and determine if the issue is with the pump or the supply...

Because this is a triple-pump system I'm managing my CPU Pump and its radiator fans via a Quadro and both GPU Pumps and their radiator fans via an Aquero 6XT.

I am going to do some more checks [component swaps] to eliminate possible causes... but I think it might be the outer control unit/collar/shroud, the part that contains the LCD panel, control buttons and programmable LEDs.

If it is, then it will be the second of these components to fail.

Although I kinda hope that it is... because if that is the case, then it will be a quick and effortless swap to get back and running, although I don't think it's possible to purchase the shroud control unit separately. *If* it is this, then that would be the second to fail since the system went live last September.

I need to do more testing, though sadly that may take some time on my part. I'll return and report back with an outcome.

OK,

Further checking revealed completely depressing news...

It looks as though, for 2 of my 3 pump/reservoir units, the seal between the glass of the reservoir and the pump top has been leaking. For one of these, the unit lost about 4cm of fluid from the reservoir; in the second it has lost about 1cm. The leaking coolant has then pooled slightly on the pump top before running down the side and dripping from the bottom on to the bottom of my pump chamber.

I've been able to clean up the mess... but it looks as though there is a deeper problem here that needs fixing. I don't think that I can wholly trust the pumps, or the little slide-on button-operated controller. I clearly can't trust the seal between pump top and reservoir.

I'm going to say that this is entirely self-inflicted. I assembled one of these units and a mate of mine attended the other two; one of the three remains in perfect working order and two have leaked... but I honestly don't know which layout the three units went in to the case.

I need to be really careful here... there's a 2000w PSU at the bottom of the case, beneath the pump chamber, so I really don't want to put this back together unless I'm 200% confident that everything is OK. My plan is to buy 2 new pumps, pump tops, and reservoirs... I'll re-use the reservoir caps. In fact, the only part of this that I'm going to need to figure out *really* carefully is how easy this lot is going to be to dismantle.