Question Does thermal paste on stock cooler becomes yellow

Jaspreet_816

Commendable
Apr 2, 2017
91
0
1,630
0
So today i bought a new CPU cooler whose seal was opened by shopkeeper to show me contents of box. When i opened the box at home i saw that thermal paste on that stock cooler was little yellowish in colour and looks dirty and applied more than what should be. Manufacturing is mid 2018. Can anyone tell me is it because of time and thermal paste or shopkeeper just sold me used processor BTW i have not tested CPU till now thinking that if cpu doesn't work than shopkeeper will blame me for it.

Thx for help
 

Jaspreet_816

Commendable
Apr 2, 2017
91
0
1,630
0
Could you post a picture? The paste should be greyish and have no dirt in it. You could just clean it off and reapply paste using a tube. Where did you buy it?
Yes actually its a little greyish. I bought it near my house at local shop. Is it because that it was packed approx 3-4 months before and it becomes old
 
Last edited:

InvalidError

Titan
Moderator
Most pastes are chemically inert and won't change color much if at all over 10+ years. The typically use silicone oil and silicone oil is stable up to about 800C which is never going to happen in a PC unless it is on fire. Other components in thermal grease may be zinc oxide, aluminum oxide, graphite, diamond powder, etc., all also chemically stable up to impossibly high temperatures for electronics.

3-4 months in storage should have no measurable effect on pre-applied paste.
 
The paste would look circular and spread out of the cooler was used. It would help to have a pic. I dont know of any paste that is yellow so i doubt they reapplied any. I would chalk it up to a defect and clean the paste off. You then could then use at tube of paste and apply it to the cpu to check if the cpu works.
 

Jaspreet_816

Commendable
Apr 2, 2017
91
0
1,630
0
Actually when i took out wraith spire out from ryzen 7 2700 box at the bottom of cooler there was 1-2 black marks on heatsink. On copper core where there is thermal paste it was having some dark grey spots on paste, it was having a pattern and paste looks like it was spread more than it should be. Is it usual or something is different. Sorry but its my first time building pc and i am little worried
 

Karadjgne

Titan
Herald
That's factory paste. You can even see which direction the safety plastic was removed, or the cooler placed paste down at some point, there's an irregularity on one edge. Also looks like someone stuck a fingertip on the paste, just to check.

It'll be fine, the actual die size is well within the borders of that paste.
 

Jaspreet_816

Commendable
Apr 2, 2017
91
0
1,630
0

InvalidError

Titan
Moderator
Surface oxidation on copper doesn't have any meaningful effect on cooling, though I'd be curious about the storage conditions that have allowed the copper to tarnish so quickly.

The aluminum looks fine to me. The thing is cut out of extruded aluminum and apart from the copper insert's hole, the other dimensions aren't critical so the machining shop doesn't bother tuning the machining for the cleanest cuts using the sharpest milling heads. Surface finish ends up looking rough and uneven, which is fine since it doesn't impact cooling performance, allows the machine shop to spit those out quicker and cheaper. Droplet-shaped marks are probably just coolant/lubricant that stained the aluminum during machining, which also has no meaningful effect on cooling performance so shops don't bother cleaning this either.
 

Jaspreet_816

Commendable
Apr 2, 2017
91
0
1,630
0
Surface oxidation on copper doesn't have any meaningful effect on cooling, though I'd be curious about the storage conditions that have allowed the copper to tarnish so quickly.

The aluminum looks fine to me. The thing is cut out of extruded aluminum and apart from the copper insert's hole, the other dimensions aren't critical so the machining shop doesn't bother tuning the machining for the cleanest cuts using the sharpest milling heads. Surface finish ends up looking rough and uneven, which is fine since it doesn't impact cooling performance, allows the machine shop to spit those out quicker and cheaper. Droplet-shaped marks are probably just coolant/lubricant that stained the aluminum during machining, which also has no meaningful effect on cooling performance so shops don't bother cleaning this either.
It is the stock cooler which is provided by ryzen 2700. Wraith spire and i just purchased the cpu from local shopkeeper
 

ASK THE COMMUNITY

TRENDING THREADS