Melting sata power cable

[Spydawg]

Hi all..

I had a sata power cable melt on a Hard Drive about 6 months ago.

It's was a 12v to Sata power adapter, I replaced it with a new one and the drive had no issues.

Last night it happened again on the same drive, replaced the adapter again and it's rebuilding now.

 

Could this be the drive? or power supply? 

 

The power supply is a Corsair 750w.

 

The system has 10 hard drives and 1 SSD

 

 

[pwm]

The PSU has the ability to produce a huge number of amps on the 12V output. Way more than a single cable or connector can handle.

 

If the PSU was the cause for the problem it would require that the PSU emitted serious overvoltages - and that would smoke everything in your computer since just about everything draws the energy from the 12V rail.

 

So you either have an issue with the drive, or a quality issue with the cables or you somehow manages to short 12V to the chassi. Have you verified that you aren't using too long screws mounting the drive? And no sharp edge of the case cutting into the cable isolation?

[Spydawg]

Nope the drive has this plastic thingy that snaps it into place..  no screws. and the rack its in has a rubber coating on it too so no metal on metal.

 

Also this drive is half way up between other HDs.

 

I removed the drive and and checked the slot for damage or something that would be shorting out the drive.  Didn't see anything.

 

I replace it this time with a sata power cable splitter from the drive above it, so its off that 12v one It was using.

[pwm]

Just a follow-up - exactly where did the cable overheat? At the PSU connector? At the SSD connector?

 

If two connectors don't make good contact, there will be a voltage drop over the connector because of the contact resistance. This voltage drop will result in heat. The hotter the connector gets, the faster the metal will oxidize which leads to even worse connection with an even larger voltage drop.

 

The drive would normally have gold-plated connectors if powered by a SATA power cable, while the Molex-type connectors do not have gold plated surfaces.

 

So if the fire happened at a connector, you need to verify that the connector surfaces of the PSU cable or the drive is in a good enough state. It will not help to replace a cable if the mating connector has the contact surfaces already damaged.

[CHBMB]

Might be worth posting some pics of the connector......

 

And then consider dissecting it open.

[Spydawg]

[pwm]

I would recommend that you try to get a sharp and high-res photo of the power connector on the drive, so you can zoom in and see if the contact surfaces are in a good enough state.

 

And I would also recommend that you touch the connector to get a feeling if it heats up. If the connector gets hot then you will get another cable fire within time.

[Spydawg]

I have been touching it during the Data rebuild..   been running a few hours now and it's not any hotter than the other cables on other drives.

 

I will be keeping an eye on it..

 

And I'll double check the drive connection again after the rebuild is done.

 

[bfh]

Molex to SATA power adapters are notorious for catching on fire, especially the ones that have the wires terminating in them instead of passing through. I refuse to use them in any computer I build because I don't want the whole computer going up in flames. I recommend getting a new power supply.

[mrbilky]

By the looks in that photo I would have a fire extinguisher nearby you know what they say 3 strikes your out!

[Frank1940]

Looking the connector, I can see bare wire on two of the conductor wires and one of them appears to a 'black' wire which is ground.  That would lead me to it was a short between the a supply line and one of the ground returns and from the location of the damage, it was apparently inside of the SATA power connector.  If you look at the spec for this connector, it has 15 pins---  3 pins for +12V, 3 pins for +5V, 3 pins for +3.3V, and 6 pins for ground returns.  So provision must be made to attach each power wire to 3 pins on the socket .

 

This would lead me to suspect that something was array awry in the mechanical assembly that allowed a short to occur inside of the socket itself.  I would guess that the current flow was somewhere in the plus 30 ampere range to cause this much damage.  

 

As was suggested earlier, double check the hard drive end of this connection to verify that the heat did not damage the contact surfaces or warp the plastic.  Clean the contact surface with Alcohol and made sure (if the drive still works) that the connection stays cool.   

 

EDIT 2:   IF you have any other Molex-to-SATA power adapters from the same purchase, I would throw them away right now!!!!   

Edited February 14, 2018 by Frank1940
Wrong word

[Jcloud]

23 hours ago, Spydawg said:

Could this be the drive? or power supply? 

 Short answer (ouch, bad pun) is it could be either. I would say it's more likely to be the PSU, but this level of failure (from your picture) I would play it safe and yank both.

 

Also Frank1940's info is also good, well communitys of it really.

Edited February 14, 2018 by Jcloud

[Spydawg]

Thanks for all the info everyone..  The drive did pass the rebuild process.

I pulled the drive again and cleaned it again with alcohol, the connections looked fine.

This was the only drive using a Molex-to-SATA adapter, I replaced it with a good Sata-to-Sata x2 splitter I picked up today.

 

Before I powered down the server, I touched all the sata power cables on each HD and they were all cool to touch. 

I'll be checking the cables every other day just to make sure until my new power supply comes in.

 

Thanks again.

[SSD]

 

Seems likely cause. I'd be looking to mitigate so this does not happen again!

[Frank1940]

My personal opinion would be that any good modern computer PS should not be damaged by a short circuit on ANY of its output busses.  They have excellent internal protection circuits to provide that type of protection.  (In fact, because the insulation was virtually destroyed on those two leads was the reason that I surmised that the current was in the 30 ampere or slightly higher range.  There is current protection that kicks in when the peak current exceed the rating by a very small percentage.  I know that several years when I was specify PS's for use in Test Sets that I was designing, the voltage would 'fold back' to only 1-3 Volt level when the current rating was exceeded.  Remember that PS will deliver about 60 Amperes on that 12 V rail.  Some of the other Disks drives on that buss probably stayed on line while the whole smoking thing was going on!) 

[Frank1940]

A video that shows the difference between the 'good' molex to SATA power adapters and the 'bad' ones that have caused catastrophic  overheating (OR possibly even fire like conditions)  at the SATA power end of the cable.  

 

       

 

If you don't think this is a problem, do a search on YouTube

Edited February 14, 2018 by Frank1940

[justinwebb]

knew before i even clicked on this thread it would be about a molded molex to sata.  The old saying holds true: Molex to sata, lose all your data.

[Frank1940]

Cable ties should be safe to use but one does have to use a bit of judgement of how tight to pull them.  (Personally, I think they should be just tight enough to prevent the tie from moving more than about 1/16 of a inch. If it does not move, it is probably too tight.)  But at the same time, I am not be biggest fan of cable dressing just for appearance sake.  For example, cable-tying SATA data cables tightly together can cause cross-talk which can lead to CRC data errors.  (With SATA data cables, you also have to be careful to avoid any axial strain on the connector as that can 'loosen' the connection because of the very low retention force inherent in the connector design!)

Edited December 16, 2020 by Frank1940

[Djcross1976]

Will the sata  power cable from PSU be ok to use there is a bit of give and take on cables incase I need to get to them in future but not alot as case doesn't have alot of space for cable management inside and absolutely none at other side panel for cabling 

[Frank1940]

You are going to be in the same situation as anyone who is using that case.  Just leave slack in the cables so that is no axial force on any SATA cable that would tend to unseat the cable.   Hopefully, this server will not be subject to a lot of vibration/shock that tends to aggravate these types of problems.