Shorted layer fan

LAGR
Plasticator
Posts: 14
Joined: Mon Jul 20, 2015 5:16 pm

Shorted layer fan

Postby LAGR » Thu Apr 27, 2017 3:28 am

So last night i was finally getting around to wiring up my layer fan and apparently i was working too late because I managed to not notice a short in my wiring. Long story short in the troubleshooting process I connected this shorted fan to all three of my pwm fan control headers. None of my fan headers work now, they all read different voltages between 9 and 11.5 volts and nothing happens when I put a fan on the header. From the research i've done it looks like I probably shorted the mosfet (p/n PMV40UN2) but it would be great if I could get some confirmation because this definitely isn't my wheelhouse.

dc42
Printmaster!
Posts: 304
Joined: Mon Mar 07, 2016 10:17 am

Re: Shorted layer fan

Postby dc42 » Fri Apr 28, 2017 8:31 am

Do the always-on fan connectors still work?

- if no then the VIN trace between the power input terminal block and the VIN side of the fan voltage selector jumper block has probably fused and needs to be bypassed

- if yes then the PWM fan mosfets are probably fused. You can probably tell just by looking at them. You need hot air desoldering equipment to remove the old ones without damaging the PCB, after that it's easy to solder in the new ones, observing anti-static precautions.

LAGR
Plasticator
Posts: 14
Joined: Mon Jul 20, 2015 5:16 pm

Re: Shorted layer fan

Postby LAGR » Mon May 01, 2017 3:27 pm

The always on works so I guess it's time to figure out how to desoldered the mosfets.

dc42
Printmaster!
Posts: 304
Joined: Mon Mar 07, 2016 10:17 am

Re: Shorted layer fan

Postby dc42 » Wed May 03, 2017 2:10 am

You need hot air desoldering equipment to desolder the MOSFETs without damaging the PCB traces.

LAGR
Plasticator
Posts: 14
Joined: Mon Jul 20, 2015 5:16 pm

Re: Shorted layer fan

Postby LAGR » Sat May 06, 2017 8:13 pm

I ended up using flush cutters to cut off the old fets, tinned the pads, and used a wooden toothpick to hold down the fet and tapped the legs one by one to solder them. It worked but I certainly wouldn't recommend it.


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