New DDC pump randomly stops working

Chen G · August 21, 2020

I have one of those flat res/pump combo things from EKWB with a DDC pump on it, it’s only like 2 month old but a week ago it just randomly stopped working. It didn’t stop while powered on, instead it just suddenly wouldn’t start when I started the PC.

I thought it was dead so I sent an RMA request to EKWB, I think two days later they got back to me saying I need video evidence so I took my phone, started recording, tried to show the impeller, turned on the PC, and the pump was working fine somehow. before this, I have tried many things in the previous two days, setting the speed to max in BIOS, adjusting the power connector, I even connected the molex to another PSU to try to power it externally, nothing worked but it magically fixed itself after I plugged it back to its own PSU and verified it did not work!

So now a week later, I used the PC every day and it worked fine everyday but today the pump won’t start again, same as last time. Anybody with experience with pumps? Any guesses as to what’s happening?

Enderman · August 21, 2020

Is it connected to molex?

Also for the record DDC pums suck and are unreliable, so...

Lipe123 · August 22, 2020

Does it only have power or also a cable that connects to a fan port for monitoring?

If it has a motherboard header try unplugging that and just leave the molex power.

Chen G · August 31, 2020

On 8/22/2020 at 12:25 AM, Lipe123 said:

Does it only have power or also a cable that connects to a fan port for monitoring?

If it has a motherboard header try unplugging that and just leave the molex power.

yes I did, still wouldn't turn.

I contacted EKWB they sent me a new one and I took my loop apart. The pump does turn just fine after I took it out, but I can feel the rotor has more resistance compared to the new one, no idea why. If I swap the rotors for the two motors then they have about the same resistance.

For Science! · August 31, 2020

2 minutes ago, Chen G said:

yes I did, still wouldn't turn.

I contacted EKWB they sent me a new one and I took my loop apart. The pump does turn just fine after I took it out, but I can feel the rotor has more resistance compared to the new one, no idea why. If I swap the rotors for the two motors then they have about the same resistance.

I'm guessing this pump in question came from this build? Are you sure you haven't just clogged the system/pump with your rheoscopic fluid?