HP Z420 CPU fan error

[BogdanP1]

Hello,

I've seen a bunch of related issues on here, but none with a clear solution for my case.

I started seeing the 511 CPU fan error on startup on my HP Z420 workstation. It uses a liquid cooling fan type which I suspect has run its course.

The problem is that the motherboard expects a 5 pin connector for the fan so replacing it is not an easy task. I can't find any replacement part for it either since it's been discontinued. Are there any solutions for this apart from selling the whole thing piece by piece?

I've also tried a 4 pin cooler but it isn't recognised by the system.

[BeemerBiker]

Those parts are still available.

You did not list your product ID so I cannot verify the exact part you need.

Go here

https://partsurfer.hp.com/partsurfer/?searchtext=B5N54LT&searchby=product

and change the product ID I guessed at to the actual product ID then look for the fan and/or assembly

A search of ebay is also productive but the exact part number (not lproduct id or mode) is needed

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=hp+z420+fan&_sacat=0

Some info on the error code

https://appuals.com/511-cpu-fan-not-detected-error/#:~:text=Secure%20CPU%20fan%20connections,cables%....

On my Z400 motherboard I had to jumper pin 5 to ground else the 4 pin fan was not recognized.  You have liquid cooling by HP and should stick with the recommended fan and / or fan assembly.

Hope this helps

[BogdanP1]

Thanks for the detailed response!

There are a couple of issues with the proposed solution, I already searched across the internet for the fan product id but couldn't find one that's applicable to my situation, given that I'm based in Europe and very few ebay vendors ship computer parts here.

The workstation serial number is CZC30145FZ and the liquid cooling fan assembly is 647289-002. This has been replaced from what I see with 714220-001. Both of these are not available on part surfer and the few that I could find on ebay are very expensive (with shipping cost included) compared to even high performance Noctua fans for example.

I would much rather invest in an aftermarket fan that can be reused in the future than an outdated HP fan assembly that uses that proprietary 5pin connector.

From what I can see the Noctua NH-D15S would fit since it has that asymmetric design and it's performance rating surpasses the HP liquid cooling assembly. Would using a jumper pin from 5 to 1 work safely with this or do I need to check something else?

[DGroves]

the HP 5 pin connector is usually nothing more than a std 4 pin PWM connector with the extra 5th pin being connected to the fst pin with a wire

    x  x  x  x  x  x    <------Pwm connector pins 1-4

    |...................|

             |

       wire runs from existing Black wire to Pin 5

https://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/Z420-Problems-with....

you can remove the label from the existing fan and use a multimeter to id the gnd/12v lines

while any 4 pin pwm fan can be used by adding the jumper wire, the HP fan is tuned to the system and will have a default RPM that allows proper cooling through the bios. A aftermarket fan may not provide proper cooling due a different default rpm

last, hp parts can have several different numbers for the same part depending on if it's a orig part number a replacement part or a CTO (configure to order)

647289-003 is the  same as 714220-001  for the entire liquid cooling unit,... (cooler and fan)

if you want just a replacement fan, remove the existing fan and use the part number on it's label to find a close match, the last few letters/numbers may be different as HP usually uses a custom variant of a retail model 

[BogdanP1]

I've searched ebay (since it's the only seller of these fans, HP has discontinued production) for every type of product code and apart from sellers from China (which I don't trust frankly), US (which doesn't ship to Europe) there are only Germany sellers with prices ranging from 200$-800$ (without shipping). I'm sorry but this is not an acceptable price which is only driven by scarcity and frankly HP should provide official replacement parts wherever it sells its workstations.

Sorry for venting, but I'm tired of searching for an unnecessarily complicated solution for such a simple problem, it's only a broken fan...

[DGroves]

post a picture of the label on your existing fan

[joselso]

FYI:

Two reliable sources of HP parts for discontinued workstations are:

1. In the UK and Europe: https://www.procurri.com/products-and-services/
(fill in the Enquiry form on the web page);

2. In USA:
https://www.itcreations.com (use the Search field in the website)

Both sources provide international delivery.

[BogdanP1]

[DGroves]

again,..................REMOVE THE FAN, flip it over and take a picture of the label with  the fans part number

i DO NOT require a picture of the HP Liquid cooler part number I NEED THE FAN PART NUMBER

[BeemerBiker]

Aliexpress has the part

https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20220215065333&SearchText=hp+647289-00...