Cable melted from fan PWM HUB to CPU_FAN on mobo. Now pc not starting.

[rob.a.mcdougall]

Hi there,

Just built my first pc. All was working well except the case fans weren't working, and when I connected a cable per below it melted. Now computer isn't working.

NZXT H440 Case => Gigabyte GA-880GA-UD3H
https://sta3-nzxtcorporation.netdna-ssl.com/uploads/download/attachment/243/H-440-manual-multi-language.pdf
http://download.gigabyte.cn/FileList/manual/mb_manual_ga-880ga-ud3h_v.2.2_e.pdf (page 14)

Pics here for ref: https://photos.app.goo.gl/kdS4mNzdX486xA347

The CPU Cooler was plugged into the CPU_Fan socket, and worked fine.

After some guidance from NZXT support, I moved the CPU Cooler 4pin connector onto the 3pin Fan Hub. I then connected a 4pin header cable from the 3pin Fan Hub to the 4pin CPU_FAN (where the CPU cooler previously was) on the mobo.

https://photos.app.goo.gl/7FgwbRGYbmGeBcz28

I double-checked polarity and was sure I got it right using the mobo manual as this as ref for the 3pins:
https://allpinouts.org/pinouts/connectors/motherboards/motherboard-cpu-3-pin-fan-connector/

I used a flat 4pin header cable at both ends. Like this one: https://d2kmb61w1swc5t.cloudfront.net/images/10177-03.jpg

When I connected the cable from HUB to CPU_FAN, the wire burnt and melted right away. So clearly I'd done something wrong.

I then put the configuration back to pre Fan Hub setup (ie CPU Cooler to CPU_FAN). Now when I power up there's power to led lights etc, but nothing to CPU Cooler, or monitor. The case light flashes every 2 x seconds.

Is there a chance I've killed the mobo and/or CPU, or ram and GPU or PSU? What's the best way now to test the components to see if I killed them or not?
I read about "breadboarding" on another thread - I think I get it. I do have the old case I transferred the mobo from, so can give that a try as well to see if it works (it was how I bought it - but not tested).

Any suggestions on what to try though before I head into that would be greatly appreciated.

Thanks in advance.

 

[cin19]

I used a flat 4pin header cable at both ends. Like this one: https://d2kmb61w1swc5t.cloudfront.net/images/10177-03.j...

When I connected the cable from HUB to CPU_FAN, the wire burnt and melted right away. So clearly I'd done something wrong.

That means your MB maybe gone, and hopefully that will not kill other components. May read through this NZXT H440 Owners Club thread, you may find what causes the problem.
https://linustechtips.com/main/topic/117203-unofficial-ltt-nzxt-h440-owners-club/?page=48

You can try this: Bench it - Troubleshooting http://www.tomshardware.com/faq/id-1753671/bench-troubleshooting.html

 

[rob.a.mcdougall]

Thanks cin19, much appreciated. Seems some others with H440 had similar struggles. My PWM Hub is an different version to others, as the case came out with 2 x variations.

I can't see visual damage, but guess it's potentially done already regardless. I have nothing else to lose at this stage so will go through the Bench it steps removing CPU etc, and pray I haven't killed it (or especially the other components) - but sounds slim chance the MB isn't toast. So gutted as I've waited ages to get the bits to build a pc and was so excited to have it working...

Thanks again for the links and help so far.

 

[rob.a.mcdougall]

I did a slightly cut down version of Bench it. I haven't yet pulled the CPU and reinstalled, but did the rest step by step as a test. Not much changed, except if I didn't plug in the CPU power, it then hung.
The CPU cooler wasn't powering at all (when connected to CPU_FAN) so instead I connected briefly to SYS_FAN, and it worked. So that at least tells me the CPU cooler still works, but the CPU_FAN connection doesn't - which I guess isn't a surprise.

I came across this video too, where a guy replaces a faulty mosfet that has an open circuit: https://youtu.be/PesCvN9losE
I'm wondering if maybe that might be the case with mine. I'll try and get hold of a multimeter with a beep and test. (then of course find a replacement mosfet and someone with the right gear to heat it to remove and replace if that's the case). One step at a time.

Mosfet pic
https://photos.app.goo.gl/Un58JDfYq9CtLNvq9
Looks like it has 2 x types of mosfets - no idea where to get them, 4921N R043 and 4935N R051

Anyway still open to other suggestions if it sounds like I'm going wrong direction.

 

[cin19]

If you did remove all the RAM, the GPU, disconnected the boot device, used onboard HD4250, clear the CMOS, after those step, if the PC will not boot, and the MB has problem at least.

 

[rob.a.mcdougall]

Yes I did all those steps. I tried the DVI connector not VGA, but gather it makes little difference. Yes definitely still a problem, which is why I'll try and test the mosfets.

 

[cin19]

Because the fan hub cable melted, that killed the cpu fan header and the MB, it don't matter you try to replace the mosfet or not. Also check the cpu to see it has the burn mark or not.

 

[rob.a.mcdougall]

Checked the CPU. No marking at all. Nothing visually on the board looks damaged anywhere.