Red CPU error led on motherboard

Slam · 24 Sep 2017 at 10:41

I bought a 2nd hand i7-2600k sandybridge processor to replace my i5-2500k.
Swapped the CPU out but pc won't post. The cpu error led on the motherboard is on.

Is there any point wiping BIOS and trying other troubleshooting things or is the CPU dead on arrival?

Slam · 24 Sep 2017 at 11:03

Have put my old faithful 2500k back in, after what seemed like long long delay the pc posted and took me to the bios. settings seemed as normal and so I exited and booted up. thankfully my PC seems to working fine again.

I will try and return the second hand cpu (fingers crossed it'll be refunded)

Slam · 24 Sep 2017 at 12:02

I am on latest bios, last update was 27 Nov 2012.

As gavinh87 says, the 2500k and 2600k should be supported on same bios rev anyway, certainly enough to post.

I should have know PCs by now, there's always something to go wrong

Slam · 24 Sep 2017 at 12:31

jigger said:
What motherboard is it?

Asus P8 Z68-V Pro

Slam · 24 Sep 2017 at 13:44

2600k supported since bios version 0221

CPU is dead then

Slam · 24 Sep 2017 at 15:07

thanks for the responses (need to get my post count up so I can access the members market)

Slam · 24 Sep 2017 at 15:14

jigger said:
Have you overclocked the 2500? Most of them offer a lot of headroom.

yes, ran a 4.2Ghz overclock for the first 5 ish years. now running at 4.5Ghz. Just used the auto overclock feature in the bios and put the bclk down to 100 and multiplier to 42, now 45

Slam · 24 Sep 2017 at 15:43

jigger said:
Is that all it will do?

It's all I've tried, wanted it to last

Slam · 24 Sep 2017 at 15:45

Orcvader said:
Did you clear the CMOS and see if that helps? If you didn't reset it and just swapped the CPU over, it could've been trying to run your overclocked profile on the 2600K.

I guess it would have but as it's also a Sandybridge chip I figured it'd just work. When I put my old cpu back the motherboard detected there was a new cpu and took me into the bios. This didn't happen for the i7-2600k so I think there's something wrong with it

Slam · 24 Sep 2017 at 19:10

Would take more than 2 minutes, not a huge deal but would need to remove a case fan to get to mboard jumper. I think I'll just try and return it, if the shop gives me grief and doesn't refund it then I may give it a go.

The store sent it by post, a naked cpu in a bubble wrap pocket just wrapped in the courier bag :-/

Slam · 28 Sep 2017 at 15:54

Just to say... the shop is exchanging the CPU for another. Hopefully this one will work, I'd be unlucky to get two faulty ones in a row, surely

Slam · 2 Oct 2017 at 10:22

I've got a replacement CPU, at a glance it looks in better condition than the last ie the model information is still clearly legible.

Plan is to reset bios settings with current CPU and then swap out. Good plan?

Slam · 2 Oct 2017 at 21:25

Duh- I forgot to reset bios settings before swapping out cpu but no matter the PC posted okay and detected the different processor. Motherboard took me into the bios and all the settings were the same so I just lowered the multiplier setting to 35, saved and exited. All seemed well, did a couple of test video encodes using handbrake.

Have now upped multiplier to 40 and run the same video encode using handbrake. The 2600k @ 4Ghz does it in 1m54s whereas the 2500k @4.5Ghz did it in 2m14s.

CPU temp peaked at 59c during a 3DMark run of the Fire Strike Extreme benchmark. At present I'm just relying on the thermal paste that was left on the cooler.

Slam · 3 Oct 2017 at 15:33

Now running the 2600k @ 4.5 GHz and I'm relieved that all seems well. This means that I'm getting the same per core performance as I had with the 2500k except with the benefits of the additional threads.

The video encode at 4.5Ghz completes in 1m42s which is a pretty big improvement. 74c during 3DMark run of the Time Spy benchmark is hotter than I'd like though.

Slam · 3 Oct 2017 at 18:15

I have now. single line down the middle

Slam · 3 Oct 2017 at 19:16

Just ran the Fire Strike Extreme benchmark and got a peak temperature of 67c - I'm happy with that

Slam · 4 Oct 2017 at 09:02

Cpu-Z reports that the voltage peaks at 1.386v so I think I need to try the offset setting before I up the multiplier.

Not done this before though so have to read up.

Slam · 4 Oct 2017 at 18:34

Read up, tried a - offset of 0.5 (largest value it would accept is 0.65) and although it posted, it failed to boot into Windows.

Slam · 6 Oct 2017 at 17:45

set offset to auto and then multiplier to 46, although it boots okay the peak voltage has gone up to 1.44v
that's quite a bit beyond the 1.35v which I understand is recommended