Power Supply HDPlex 300w AC-DC inducing horrific coil noise on a motherboard

confusis

John Morrison. Founder and Team Leader of SFF.N
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So, while building up a new system, (for a review, and for personal use), I found one of my HDPlex 300W AC-DC units induced a horrific sounding, sparky coil noise on the motherboard. I replaced it with a power brick, and then finally my backup 300W HDPlex and both of those created no noise!

Note that the DC-DC duties are taken care of with a KMPKT Dynamo Mini.

Anyone come across this? Without an o'scope I can't narrow down the culprit component, but maybe someone here has seen (heard) this before. Physically, the unit looks fine internally :/
 

Windfall

Shrink Ray Wielder
SFFn Staff
Nov 14, 2017
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So, while building up a new system, (for a review, and for personal use), I found one of my HDPlex 300W AC-DC units induced a horrific sounding, sparky coil noise on the motherboard. I replaced it with a power brick, and then finally my backup 300W HDPlex and both of those created no noise!

Note that the DC-DC duties are taken care of with a KMPKT Dynamo Mini.

Anyone come across this? Without an o'scope I can't narrow down the culprit component, but maybe someone here has seen (heard) this before. Physically, the unit looks fine internally :/

Any temp spikes? I had a 160W that was doing that. With the help of a friend who does electrical engineering, I fixed it by replacing a mosfet and capacitor. It also boosted it to 230W. Check if it get hot (like too hot to touch) under load. If it doesn't get hot, probably not the same issue.

With the upgrades though it still is hot, no coil whine tho. :/
 

confusis

John Morrison. Founder and Team Leader of SFF.N
Original poster
SFF Network
SFF Workshop
SFFn Staff
Jun 19, 2015
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This is at boot - no temp in the system at all :/
 

Windfall

Shrink Ray Wielder
SFFn Staff
Nov 14, 2017
2,117
1,582
This is at boot - no temp in the system at all :/

Maybe a short inside the case? Try using an HDplex 160 instead of the KMPKT unit. I know they are Identical, but maybe....

Try the unit with a different mobo as well.

I don't know what else to do. The cringe is real. :/ (are we starting a chain of these faces? :D)
 

confusis

John Morrison. Founder and Team Leader of SFF.N
Original poster
SFF Network
SFF Workshop
SFFn Staff
Jun 19, 2015
4,129
7,057
sff.network
@Windfall - just replacing the flakey 300W unit with another i had spare solved the problem :p Just wondering if folks have seen the fault before. The case is acrylic so shorts, not so easy to cause XD
 

confusis

John Morrison. Founder and Team Leader of SFF.N
Original poster
SFF Network
SFF Workshop
SFFn Staff
Jun 19, 2015
4,129
7,057
sff.network
Previous generation - the 400W replaced the 300W :)
 

Windfall

Shrink Ray Wielder
SFFn Staff
Nov 14, 2017
2,117
1,582
@Windfall - just replacing the flakey 300W unit with another i had spare solved the problem :p Just wondering if folks have seen the fault before. The case is acrylic so shorts, not so easy to cause XD

Contact Larry. He'll sort it out.

Previous generation - the 400W replaced the 300W :)

Sadly. The 300w was usable with STX and a GPU because of it's size. The 400 is too big... :/ (had to use it again lol)