Question Oily-Looking Residue on PSU Cables

[pandaparlor]

Hello, so I recently got my new PSU (Corsair RM850x) and was going to install it, but before I did, I noticed a shiny, oily residue on the ends of almost all of the cables that came with it. The color of the stains are a very darkish red. I tried rubbing it off with a dry q-tip, but it wouldn't come off. You can see for yourself in the attached images below.

Cable 1
https://ibb.co/qwQTj95
https://ibb.co/9HbXWBSn
https://ibb.co/sdthJbkd

Cable 2
https://ibb.co/7xKg128K
https://ibb.co/gbhWzv49

Cable 3
https://ibb.co/nty5GB9

What is this shiny residue? Is it normal?
And if not, should I get the PSU returned or try cleaning it off myself with isopropyl alcohol?

 

[Lutfij]

Hello, so I recently got my new PSU (Corsair RM850x) and was going to install it, but before I did, I noticed a shiny, oily residue on the ends of almost all of the cables that came with it.
Don't tamper with it, keep a video/images of the issue you've stated above. Return to seller/RMA the unit. It shouldn't be like that out of the box.

Could be a returned unit or it could be someone trying to fabricate a custom harness by marking the first or last pin on the connector but your images look like the marking was made randomly. Either which way, I'd return it. FYI, isopropyl alcohol will denature the plastic connector, which is something you shouldn't allow if you intend to hold onto the PSU for a long while.

 

[Eximo]

Those are likely just marker marks. Used at the factory to confirm the cable has gone through some quality control step.

Alcohol would probably take them off. If not, they are on the outside of the connector, not actually going to harm anything being there.

 

[pandaparlor]

Hello, so I recently got my new PSU (Corsair RM850x) and was going to install it, but before I did, I noticed a shiny, oily residue on the ends of almost all of the cables that came with it.
Don't tamper with it, keep a video/images of the issue you've stated above. Return to seller/RMA the unit. It shouldn't be like that out of the box.

Could be a returned unit or it could be someone trying to fabricate a custom harness by marking the first or last pin on the connector but your images look like the marking was made randomly. Either which way, I'd return it. FYI, isopropyl alcohol will denature the plastic connector, which is something you shouldn't allow if you intend to hold onto the PSU for a long while.

Okay, I won't try cleaning it with isopropyl alcohol.
And I'm new to PC building, what's a custom harness?
And how can I tell which pins are the first/last pins? Would it be the left-most or right-most pin on a particular side of the connector?

 

[pandaparlor]

Those are likely just marker marks. Used at the factory to confirm the cable has gone through some quality control step.

Alcohol would probably take them off. If not, they are on the outside of the connector, not actually going to harm anything being there.

If that's the case, have you seen them on your power cables before?

 

[Gururu]

Those are likely just marker marks. Used at the factory to confirm the cable has gone through some quality control step.

Alcohol would probably take them off. If not, they are on the outside of the connector, not actually going to harm anything being there.

Thats what I was thinking. I could find at least one source, so maybe OP can contact the manufacturer.
marks

 

[pandaparlor]

Those are likely just marker marks. Used at the factory to confirm the cable has gone through some quality control step.

Alcohol would probably take them off. If not, they are on the outside of the connector, not actually going to harm anything being there.

Looks like you were right. I found Corsair's PSU FAQ page, and as they say, "PSU cables are often tested to make sure that they are pinned correctly. When the cable passes the test, it is marked with a Sharpie Marker to show that is has been tested and passed."

A bit dumb of me to have not searched more carefully, but hopefully this thread will be of use to anyone else that runs into the same problem.