Broken sensor 4790k?

[Kashinoda]

My friend's CPU keeps thermal throttling.

I've reapplied thermal paste twice. Heatsink looks fine, no warping (BeQuiet Rock Pro 2). I've under-volted from stock too.

BIOS is reporting 91 degrees when not even booted into the OS.

Interestingly CoreTemp is showing 2 cores are red hot whilst the other two look normal:



Could it be a busted sensor or shoddy thermal paste in the IHS?

 

[twistedheat]

Haswell had some proper crap in their IHS. Try a delid. Nothing to lose at this juncture.

 

[Justintime]

Was the 100% load intentional?

 

[Kashinoda]

Haswell had some proper crap in their IHS. Try a delid. Nothing to lose at this juncture.

Yeah looks like that might be the case, I'll delid it when Ryzen 3 comes out. Worst case scenario he can get a 3600X or something.

Was the 100% load intentional?

Yeah I was running Prime95 to see if there was actually any heat, had my hand next to the heat-sink and it didn't seem hot at all.

 

[Justintime]

Delid and see, its so easy. I don't have a delid tool but have been using a vice, block of wood and mallet since Ivy Bridge and its literally 3 seconds. I know theres talk of microfractures with this method but no cpu has failed up to now.

 

[Kashinoda]

Will do.

Think I can get away with just delidding, cleaning and applying thermal paste without scraping off the existing silicon glue?

 

[tyler_jrb]

Will do.

Think I can get away with just delidding, cleaning and applying thermal paste without scraping off the existing silicon glue?

You don’t need to replace it, however it’s best if you do as without it the IHS tends to try slide around when you tighten the motherboard socket latch. I only usually put a few small blobs to keep it in place when mounting and removing the cpu. However it scrapes off very easily with a wooden toothpick or plastic scraper without risking damage.

Bit risky in a vice if it decides to go wrong. There are services on eBay for like £10-15, which will delid, apply liquid metal and replace all glue.

Vice method is usually ok but can go wrong. Can also borrow my custom delid tool if you want depending on where you live.

 

[Kashinoda]

You don’t need to replace it, however it’s best if you do as without it the IHS tends to try slide around when you tighten the motherboard socket latch. I only usually put a few small blobs to keep it in place when mounting and removing the cpu. However it scrapes off very easily with a wooden toothpick or plastic scraper without risking damage.

Bit risky in a vice if it decides to go wrong. There are services on eBay for like £10-15, which will delid, apply liquid metal and replace all glue.

Vice method is usually ok but can go wrong. Can also borrow my custom delid tool if you want depending on where you live.

I think I'd try it id it was my chip personally but don't want to mess around with someone elses.

Those delidding prices are pretty cheap on eBay, thanks for that will just go for those.

Think I'll just upgrade to Ryzen next week, give him my 4790K then repair his old one. God forbid anyone has any down time

 

[Justintime]

Fingernail will do to remove the epoxy. Results may vary but i do find better results with it removed as it might add height to the IHS and prevent the best thermal transfer.

 

[an0nym0us]

Will do.

Think I can get away with just delidding, cleaning and applying thermal paste without scraping off the existing silicon glue?

It's better to use liquid metal between the CPU die and IHS, rather than regular thermal paste.

I've used Thermal Grizzly Conductonaut and been happy with it:
https://www.overclockers.co.uk/ther...-liquid-metal-thermal-paste-1g-th-021-tg.html

 

[an0nym0us]

Also some nice general info on delidding here:
https://youtube.com/watch?v=w9i_ULemBhI