PSU modular connectors are non-standard and dangerous

So the story begins when two Western Digital WD740 Raptors started their journey together and worked in strip relentlessly. One unsuspecting day, when the PSU was replaced on the PC and the modular cables that came with the PSU was not replaced since the previous PSU. Turned out that the cable ports were same but the wires were in different places. I don’t know exactly what went where but I guess, the little two Raptors got 12V in their 3.3V Sata-power inlets. Jipes! They both went out with a bang, smoke and flash.

The End – of the hardware

Last year I was upgrading my worn out Zalman 500W PSU and tried to get the PC working it with a bit newer one, a SeaSonic 460W model. The connectors were the same so I thought to take the lazy road and was another victim of the saying Haste-Makes-Waste.

The common 6 pin PSU cables were actually different and this resulted in a 4 blown HDD’s and 1 dead DVD-ROM.

Here are the models and wires that were different:


And here is a shot of cables, they have different wires, they are both SATA power cables and  they both plug in to the beforementioned different PSU connectors!


Here are shots of PCBs. Two top PCB’s are blown and two bottom ones are good ones that I tried to replace and fix.


So yeah, whoever stumbles on this post here, take my note, never ever trust different brands or even same brand different model modular PSU cables to be same.

You can read some more about this story here, where I tried to take all to repair the HDD’s

ALWAYS test different cables for polarities and correct voltages!

There is a simple rule for that. Cable colors are coded and can usually tell you what sort of a voltage should be running through it.  So here is a basic list:


BUT This does not mean that the voltages from PSU are still right! Only way to be sure is to test PSU voltages with a voltmeter is the best way!

2 thoughts on “PSU modular connectors are non-standard and dangerous”

  1. True story, too bad I had to learn it the same (and even more expensive) way. Even though I told my story to guy in service, he told me that it can’t be a should work and encouraged me to try it in another computer – so I burned another devices in another computer also. Next time I should re-check informations I’m getting before applying :D. I’m wondering what is the point of changing cables by different vendors in connector using for same thing with same shape – disc producers must be happy now :D.

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