Cheap ass cables, not worth it!

Curious Pineapple · June 5, 2019

Been without my workstation for a few weeks after my power supply shat the bed and I lost the arsedness to fix it.

I've bought some adaptor leads from China (good quality) and got it running again with 1 CPU, they convert a standard ATX supply to HP's odd standard. As I needed a second EPS power connector to use both processors, I bought a couple from eBay in the UK (the 4 to 8 adaptors), chopped the 4 pin end off and spliced them in. Within 5 minutes of starting CB20, there was a smell, smoke, a couple of flames and a rather abrupt shutdown followed by a power supply beep code. The wires on the EPS adaptor (that should be rated for 280W) were on fire and melted together.

I'll explain a bit. The board has a single EPS connector for both CPU's, and also has a connector for the RAM power supply. The adaptor lead set I bought converts an EPS to power the RAM so I needed a second one. I wrongly assumed that a cable sold as an EPS cable would be rated high enough for the task, I guess not. Luckily I bought 2, so I can chop off the mess the first one made and make an adaptor just for the RAM using my patented 6-pin GPU to EPS cable.

I shall be sending some harsh words to the seller for sure. If I hadn't run CB to load test the machine and had left it running all night, it could have got hot slowly and not tripped the mainboards fault detection, possibly melting and drooping onto the mainboard.

mariushm · June 5, 2019

Are you sure you didn't accidentally connect a ground wire to 12v or something like that? You'd need a LOT of current to get wires burning.

The thinnest gauge wires would be the first to burn/break.

Check the gauge of the wires, should be at least AWG20, ideally AWG18 or AWG16 (smaller is better). Don't trust the writing, if you get measure the diameter of the actual strands inside the wire.

Also, some adapters use cheap wires that are made of steel strands instead of copper, because it's cheaper... steel has higher resistance so kinda makes the extra thickness pointless. Some mix aluminum or steel strands with a few copper strands (ex 15 strands, 3-5 copper, 10+ steel or aluminum.. again, higher resistance so higher losses in the wires.

Curious Pineapple · June 5, 2019

About 4.5A per conductor, they were definately tinned whatever they were as I soldered them just fine. Going to guess they were 9/.2 or similar size, borderline but should have coped with the load on them. Just shit quality wire, possibly tin plated aluminium or steel. I'm now using the PSU's proper EPS connector and a PCIe to EPS adaptor I made to power the RAM and it's all working fine. I need to get a better PSU though as I don't trust an Aerocool integrator with a pair of Xeons.