CoolIT ECO II-120R pump failure

[alindumitru46]

I have an AIO ECO II-120R from CoolIT for about 5 years that suddenly yielded. The temperature rose instantly to over 100 degrees Celsius, the cpu went into the throttle and shut down. It was received ast RMA from the previous model, a Coolit ECO A.L.C. 120 who suffered the same symptoms.
There is no vibration when checking the pump on the power header fan, and no fan movement is detected in the bios or in the monitoring programs.
Because I do not think there is a protection of the IC that controls the pump, it may have been ceded or, due to liquid loss, the pump has caught air and the IC has burned.
What are the chances of repairing this toy? Can I replace the IC only?
For example Laing DDC pumps has a custom pcb for DIY with a more reliable controller: https://www.diyinhk.com/shop/ddc-pum...ed-mcp350.html

[redwire]

Re: CoolIT ECO II-120R pump failure

Is the Hall sensor IC U2 burnt and cracked? It kinda looks like that.

LB11961 motor driver IC might have died (shorted) and then killed the Hall sensor.

[alindumitru46]

Re: CoolIT ECO II-120R pump failure

I am convinced that the IC controller is affected (unfortunately only monday I can do measurements on pcb), but U2 is a free place there. It seems rather the place of a coil that has never been mounted.
Now I read that this LB11961 IC has a "Built-in thermal shutdown circuit" who has not done his job very well. Maybe the "Hall sensor" has never been mounted for low cost policy, actually ...

[alindumitru46]

Re: CoolIT ECO II-120R pump failure

Ok, I did some research and here's what I discovered, using the second pump(from the first AIO), which is identical.
- both pcb are identical.
- there is the HALL sensor, mounted under the pcb on the U2 position.
But how to make measurements on controller LB11961 ?! I read the datasheet but if I am powering up there is no risk of something burning?
But Hall sensor how to check it? I think my humble knowledge is already out there

[stj]

Re: CoolIT ECO II-120R pump failure

did you check the motor winding?

[alindumitru46]

Re: CoolIT ECO II-120R pump failure

If you mean winding, it gives continuity.
I understand that checking in idle (or even the presence of air in the plant) can cause the controller to burn, and I'm afraid to do checking under voltage without having an advised opinion.

[redwire]

Re: CoolIT ECO II-120R pump failure

I would make sure the pump rotor is not stuck, that nothing is wrong with the mechanical- bearings, impeller etc.

The motor IC can operate from 4.5-16V so try run the pump dry with a lower voltage power supply.
Add a large capacitor >220uF to the power supply, to absorb back-EMF overvoltage spikes so they do not damage the IC.
I think 7V or so is the lowest that allows the internal 6V regulator 6VREG to work.

I still do not like the hall sensor picture, it looks cracked. All its voltages should be close to HB pin 1.3V. You can check the 6VREG too. Make sure the motor leads L1, L2 are not shorting to nearby PCB traces.

There's not much here to troubleshoot, it's all one big IC and a sensor and a motor.

[alindumitru46]

Re: CoolIT ECO II-120R pump failure

Ok, good to know.
I'll try tomorrow morning, it's almost midnight on me now
Thanks for tips.

[momaka]

Re: CoolIT ECO II-120R pump failure

I would make sure the pump rotor is not stuck, that nothing is wrong with the mechanical- bearings, impeller etc.

Agreed.
Check the mechanical bits first. Then we can go troubleshooting the electronics side of things, if needed.

I received two PS3 140 mm fans many years ago that were both plugged into a household 120V AC (US) outlet, and they both had completely damaged driving MOSFETs. The hall sensor in both, however, was fine (even though one of these fans had a completely shorted controller as well). Given that the controller on your pump motor also has the MOSFETs integrated in it, I would suspect that this is what's wrong with the pump and not the hall sensor, if everything on the mechanical side of things checks out fine.

That said, here's the thread of the two PS3 fans mentioned above, in case you're interested in a long (and somewhat pointless but also fun) repair. Yes, they both work now!

https://www.badcaps.net/forum/showthread.php?t=63464

[alindumitru46]

Re: CoolIT ECO II-120R pump failure

Mechanical problems do not seem to be, but I'm afraid to disassemble the pump assembly now. I have a similar system, previous model, but I have not been able to assure tightness after disassembly, decalcification and refill.

I read your adventure. Congratulations on the results, it was a great headache. I have to deepen some aspects, though.