[SOLVED] PSU cable melted, bad PSU or bad cable?

[Alexllte]

After building one PC for a friend, my plan was to run valley benchmark for 3 hours to stress-test its reliability.
About 30 minutes in, I was smelling something burning, I cut the power off and sniffed around as much as I could to see which component was burning.
Forget about my lungs, I found out that the PSU cable melted part of my carpet. (Cable that connects the PSU to outlet)

I understand I have a cheapo PSU, this is an extreme budget build. I only need to know what's defective.
Here are my PC specs:
Thermaltake tr2 RX 500w
R9 380x
FX 8150
970 motherboard from a HP Compaq desktop taken apart

 

[Karadjgne]

What cable exactly melted?
A 380x normally demands a decent 550w psu. That TR2 is not only underpowered, well it's a TR2 and that says everything.

 

[Ralston18]

PSU cable being the cable from the wall electrical outlet to the PC/PSU - correct?

This power supply?

https://www.amazon.com/ThermalTake-POWER-SUPPLY-80PLUS-PS-TRS-0500NPCWEU-2/dp/B016WFYCD2

My thoughts:

You overloaded the PSU. The GPU alone has a required power supply of 500 watts.

CPU's Thermal Design Power is 125 watts.

All in all the stress test was too much.

Neither the cable nor the PSU can be trusted again. Do not use either one again.

As for the other components - may be hard to tell.

 

[Vic 40]

The GPU alone has a required power supply of 500 watts

You mean that is system wattage.

Think he is talking about this one,
TR2 RX Cable Management 500W - W0136

Seems somehow cable got too hot. Whether that is from the psu drawing alot or that the cable is faulty (probably first). Would imo be good to change that psu to something better.
See i don't get how you got that gpu to work with only one 6pin pcie cable to power it if the above psu. Which leads me to believe you used a molex adapter which might have overloaded the second rails (it has two). Maybe where the weird/extra power draw came from.
Can only guess that the protections this psu has do not work properly or this is not covered by them.

You'll need a psu with at least two 6 pin connectors/one 8pin connector. A Corsair CX 550watt should be fine on a low budget.

 

[Ralston18]

@Vic 40.

System wattage yes.

The wattage requirement for the GPU itself seemed to be around 230 watts.

Thank you.

 

[Karadjgne]

See, my line of thinking was that it wasn't the wall-psu cable that was affected, but highly likely that when the adapter was used (a 6-pin to 2x 6pin) that the actual 6pin wire from the psu melted, since 2x 6pin can pull upto 240w through an original 120w line. With a moderate 230W draw (not including spikes) under full stress and even counting on upto 80w from the pcie slot, that's still 150w pulled on a single 120w 6-pin.

I only need to know what's defective.

Your PC building skills. Just saying. Questions like "Can I use a 6pin to 2x6pin adapter for a gpu" should have been asked before the attempt was made, could have saved you some money and a hole in your carpet, which should not have happened in the first place.

 

[Alexllte]

You mean that is system wattage.

Think he is talking about this one,
TR2 RX Cable Management 500W - W0136

Seems somehow cable got too hot. Whether that is from the psu drawing alot or that the cable is faulty (probably first). Would imo be good to change that psu to something better.
See i don't get how you got that gpu to work with only one 6pin pcie cable to power it if the above psu. Which leads me to believe you used a molex adapter which might have overloaded the second rails (it has two). Maybe where the weird/extra power draw came from.
Can only guess that the protections this psu has do not work properly or this is not covered by them.

You'll need a psu with at least two 6 pin connectors/one 8pin connector. A Corsair CX 550watt should be fine on a low budget.

You're right, that is the PSU I'm using. (W0136RU)

The cable that connects from the PSU to the GPU in question was something I had similar in storage, it has a red 8-pin side for the PSU, and black dual 6 pin side for the GPU. (I can't confirm if its part of this particular PSU, but it works so far)

I traced back the melted cable (from the PSU to outlet). As it turned out, I mistakenly swapped the 3 pin PSU cable with another 3 pin cable.
The "other" 3 pin cable came from an eBay listing for a universal laptop power supply; the exact listing description is "90W Universal Laptop Power Supply 110-220v AC To DC 12V/16V/20V/24V Adapter".
That may have been the root cause of this mess.
I can't confirm if the cable isn't designed for the required wattage, or if it's faulty.

I reran the stress test with another cable, 2:30 hours in, and I'm not dead yet.
I'll keep valley running overnight; if either component dies, then sure, ill get the 550w PSU.

But I guess that concludes this frenzy, any other suggestions or followups would be appreciated.

 

[Vic 40]

You're lucky that the random pcie cable has the same pinout and seems to deliver enough power to the gpu.

"Suggestion" ..... get something better, but that is up to you. Get the feeling you like to make things like this work like this. You're some kind of "Tech Yes Man".😁