Need some advice before proceeding

[BigDave]

Is there any negative effect with cutting off unused wires and connectors from a PSU?

I purchased a Jetway JBC150F9N-2930-B 1U appliance with the ADE4INLANG daughter
board option for my new pfSense box. I'm using a Micron M550 64GB mSATA SSD for
the boot device.
As a result of having no hard drives installed, literally the only connection I need is
the 20pin motherboard connector. This leaves me with a bunch of wires and connectors
that are doing nothing but blocking air flow! The CPU has a passive heatsink and I'm
not happy with the idle temps I've tried to bunch n' tuck but there's very
little room in a 1U box
If I properly cut and cap these unused wires, or will this do damage
to the circuits and/or other components of the PSU?

 

[Bidule0hm]

No, you can cut and isolate the wires you don't want ;)

 

[DrKK]

You can definitely cut off those wires, but, they should probably be capped or taped or otherwise prevented from the stub making an inadvertent connection. You can also, of course, open up the power supply and physically remove the wires or cut it below the water line.

 

[BigDave]

Great! I'm thinking some small diameter heat shrink tubing on the end of each wire should keep
things properly isolated, now where did I leave my side cutters...

 

[DrKK]

Great! I'm thinking some small diameter heat shrink tubing on the end of each wire should keep
things properly isolated, now where did I leave my side cutters...

A "Real Man(tm)" would open up the PSU and remove the unneeded wires :)

 

[Robert Trevellyan]

... and take pics, obviously.

 

[BigDave]

A "Real Man(tm)" would open up the PSU and remove the unneeded wires :)

You're the Devil, whispering in my ear, trying to tempt me, be gone Beelzebub!

 

[Ericloewe]

You're the Devil, whispering in my ear, trying to tempt me, be gone Beelzebub!

Warranty's void anyway, so might as well go with the neater solution.

Great! I'm thinking some small diameter heat shrink tubing on the end of each wire should keep
things properly isolated, now where did I leave my side cutters...

They also make heatshrink that's closed on one end, though getting the right size may be hard.

 

[gpsguy]

You might want to think outside the box and try a pico power supply instead.

 

[SweetAndLow]

I doubt your thermal problems are related to your cables. Passive heatsinks take a special environment to succeed. Lower power CPU high power fans with ducting.

 

[DrKK]

I doubt your thermal problems are related to your cables. Passive heatsinks take a special environment to succeed. Lower power CPU high power fans with ducting.

I know one of the guys had a passive rig on his CPU; he eventually gave up and laid a small fan at low rpm on it. Said it made a million percent difference.

 

[BigDave]

I know one of the guys had a passive rig on his CPU; he eventually gave up and laid a small fan at low rpm on it. Said it made a million percent difference.

I watched the temps shown for the CPU on the pfSense GUI drop around 10 degrees
as I placed a 40mm x 10mm fan on top of the heat sink. :) The fins of the heat sink are shorter
right in the middle and it fits the little fan perfectly.

I'll be working all day tomorrow on my mods for this chassis and will document my progress with pics.

I'm off to the electronics store in the morning for a soldering iron to cleanly and properly remove the
unneeded wires from the PSU. Anyone have a preference for solder removal tool (wicking vs. sucking),
I sure could use the advice. The last time I used a soldering iron was on a HeathKit project about 47
years ago ;)

Thanks to all of you for the responses thus far.
Dave

 

[wblock]

I'm off to the electronics store in the morning for a soldering iron to cleanly and properly remove the
unneeded wires from the PSU. Anyone have a preference for solder removal tool (wicking vs. sucking),
I sure could use the advice. The last time I used a soldering iron was on a HeathKit project about 47
years ago ;)

I would advise against that. Or at least get a scrap supply and try it there first. Imagine big bundles of wires wound together and crimped into a pin, then that pin soldered into the board. Then imagine trying to unsolder that giant heat sink with a typical junk soldering iron. Imagine lifted traces and regret.

I have some professional-level soldering and desoldering equipment, and would have to be highly motivated to attempt that. It's not impossible, but almost certainly not worth it.

Better to spend that money on a fully-modular power supply, where you can just leave out the extra cables. But it sounds like the small fan might be the solution anyway.

 

[Bidule0hm]

Yeah, just cut the wires flush with the PCB, or longer and add heat-shrink tubing ;)

 

[BigDave]

I would advise against that. Or at least get a scrap supply and try it there first. Imagine big bundles of wires wound together and crimped into a pin, then that pin soldered into the board. Then imagine trying to unsolder that giant heat sink with a typical junk soldering iron. Imagine lifted traces and regret.

I have some professional-level soldering and desoldering equipment, and would have to be highly motivated to attempt that. It's not impossible, but almost certainly not worth it.

Better to spend that money on a fully-modular power supply, where you can just leave out the extra cables. But it sounds like the small fan might be the solution anyway.

Yeah, just cut the wires flush with the PCB, or longer and add heat-shrink tubing ;)

Ok, so I'm going to shut down my internet (pfSense box) and pull the PSU. I'll see once it's opened up as to what might be the best way to proceed.
I appreciate your input/advice
See y'all in a few hours...

 

[BigDave]

Imagine big bundles of wires wound together and crimped into a pin, then that pin soldered into the board. Then imagine trying to un-solder that giant heat sink with a typical junk soldering iron. Imagine lifted traces and regret.

When you're right, you're right! As you can see by the photos, it was not not worth trying any type of desoldering, at least not with my skillset.
It amazes me how much electronics can fit into such a tight space, I did attempt to pull the PCB and get a look at the underside of the board,
but the 110v female receptacle was soldered in and prevented further inspection without a lot of work and risk.

After realizing I wasn't going to be able to cut the wires off inside the enclosure, I placed every thing back together and went to the store to buy heat shrink tubing.


Next I mounted the PWM fan and plugged it into the CPU fan header. 2,000 RPM @ 12 volts and it's lowered the idle temps from 46, down to 35 celsius!:D

I untwisted and grouped by voltage, placing 3/16 heat shrink over each wire, then placing a 1/4 tube over same color groups of 4 or 5 and put the heat gun on that.

I got rid of the larger fat wires in the front of the box and went with these rear mounted momentary switches and LEDs for power and HD activity.

There was a multi fan header board that came with the unit and was powered by a four pin molex @ 12v, but I change it to 5v and quieted them a bunch

Here's the finished product below, hope you enjoyed the show...

My next project is to attach the rail kit for the pfSense, but first I need a break ;)

 

[Robert Trevellyan]

Nicely done.