Installed new i7-7700K, reset CMOS, no post, can't boot with old processor either

[flymolo93]

Hi Guys, I have a PC I built this past Christmas 2017, with an i5-6600k. Recently, it hasn't been performing as well as I would like, so I bought an i7-7700k.

Corsair 750D case
Asus Tuf Mark 1 Z270 motherboard
i5-6600k processor UPGRADING to i7-7700k processor
Corsair H100i AIO liquid cpu cooler
Corsair LPX Vengeance ddr4-3000 memory
Samsung 256 GB SSD boot drive
Samsung 500 GB SSD games drive
Seagate 3TB HDD storage drive
EVGA 1080GTX video card
EVGA Supernova G2 850W Gold 80+ power supply

Today, I installed the i7-7700k with relative ease. I also invested in some new thermal compound https://www.amazon.ca/Thermal-Grizzly-Conductonaut-Grease-Paste/dp/B01A9KIGSI for the new processor. While thermal-pasting the processor, a micro drop of paste landed to the left of the processor cage on PCB with no visible solders, I cleaned it up.

I reset the CMOS, by shorting the two pins on my ASUS TUF MARK 1 Z270 board marked CLRTC RESET, as per my manual. After this, I plugged the power back in, turned on the PSU, turned on the PC. Booted, turns off after 1 second, boots again but never posts. Try booting again, but it just never posts, it doesn't turn off after 1 second or anything. I have one monitor in the onboard slot, one on the graphics card, just in case.

Reset the CMOS again, this time by taking out the battery, then shorting the two pins for 5 seconds, putting the battery back in. Plug in the PSU, turn on the PSU, turn on the PC. Booted, turns off after 1 second, boots again but never posts. I have one monitor in the onboard slot, one on the graphics card, just in case.

After some googling, I think whats happening is the BIOS tries to load and fails, then tries to load some other configuration. In a panic thinking my BIOS may be too old for this CPU (it wasnt) I decide to flash the latest BIOS using Asus' Flashback port/functionality. I get a USB stick and format it FAT32, download the latest BIOS for my Asus TUF Z270 Mark 1, unzip it, rename it to the appropriate flashing-bios-filename (Z270TUF1.CAP) and put it in the FlashBack port. Turn on the PSU, and hold the flashback button for 3 seconds until it starts flashing, indicating it is flashing the BIOS. The flashing continues for 2 minutes or so, never stopping or changing to a solid light indicating failure/errors. After the flashing ends, I try to boot the PC with one monitor in the onboard HDMI and one monitor in the graphics card, just in case. No post.

So now I think the CPU must be defective, it's the only part that has changed. I take out the new CPU and I check the socket and pins on the motherboard thinking I may have damaged them, but they look fine. I reinstall the old CPU, cleaning it and putting some new thermal paste on. Reset the CMOS, battery method with paperclip short. Turn on the PSU, turn on the PC, it boots for 1 second, turns off, then turns on again, never posts.

Is my motherboard toast? Tomorrow, I'm planning on 'breadboarding' to see if I can get some beeps, but I'm starting to just think the motherboard or bios is to blame--especially since I can't boot with the OLD cpu installed. The 1-second boot, then off, then on again leads me to believe something is wrong with the BIOS and a CMOS reset doesn't 'reset' it enough. What can I do? Flash it again with an older BIOS version?

Any help is appreciated.

 

[alexoiu]

If internal speaker connected, try starting the board with no RAMs and see if any beeps.
Check also the 8 pin power cable, both ends, if properly connected.

 

[flymolo93]

8 pin power cable is properly connected.
Removed ram sticks, turned on PC, no beeps. I don't think this motherboard has internal speaker, so I try once with speakers plugged in as well, no beeps.

I also tried using BIOS flashback method with older BIOS version, no post no beeps still.

 

[alexoiu]

It needs an internal speaker for beeps.
The board has ASUS Q-LED (CPU, DRAM, VGA, Boot Device LED)
What LED stays on when starting the board with single RAM inserted?

 

[flymolo93]

When I turn it on with just one ram inserted (video card removed for visibility) I see only PWR and DRAM led on. CPU led is red for a second as it boots, then off.

Currently I have old cpu in, with new BIOS. Is it possible to determine either if this is BIOS or CPU socket?

I opened up CPU cage to check socket thinking maybe pins are bent, but no bent pins. I reseated CPU, reattached cooler, power on and still red CPU_LED for one second then off.

 

[mdd1963]

Remove CMOS battery for 10 minutes, reinsert battery, try again with original CPU....

 

[flymolo93]

Trying the 10 minute CMOS reset. I think its the CPU socket, I looked inside and noticed some pins were not perfect on one side. I tried to adjust them as best I could with a 7x mag and tweezers, but they are not easy. After my 10 minutes are up, going to try booting and see the CPU light.

If still red, guess I need a new motherboard.

https://imgur.com/Wh65SOg pins. (Right side)

 

[flymolo93]

No luck guys, tried the 10 minute CMOS reset, tried to fix the pins, tried the old processor and the new one... Red CPU led every time.

 

[alexoiu]

Then try RMA-ing the motherboard.

 

[flymolo93]

I bought the same motherboard with 1 day delivery to test, because I thought it was the pins.

The brand new motherboard with the i7 installed, cooler connected, boots with a red CPU_LED, never posts...
I have read in other threads that a single red flash CPU_LED then turns off, is ok, but why cant I post?

Is it possible that this i7 is so defective that it wrecks everything it touches? I'm at a loss for ideas now.

 

[alexoiu]

What about the other CPU?

 

[flymolo93]

After reading another thread I went and referenced the manual again on the CPU_LED light. If it flashes red once, then turns off, the CPU is actually fine. I realized that I probably just wasn't giving the motherboard enough time. I was testing with the old motherboard, and I switched to the new one again and just waited with only cooler+CPU+a monitor plugged in. It got to bios fine.

I switched back to the old motherboard, and disconnected all drives and tried to boot. Green boot light (no post) but reset CMOS battery method and got to bios. Turned off, and tried again. Booted windows.


It turns out it was dumb human error combined with a misunderstanding of the red CPU_LED flash, combined with damaged-looking pins. I will test the other motherboard in the coming days--I think I probably fixed the pins enough there, and it will work just fine with the old processor in our family machine.

Maybe useful tip for anyone coming to this thread with problems upgrading processors: Even after resetting CMOS, you may have to disconnect all your drives to boot once to BIOS after you have upgraded, once you see BIOS, turn off PC&PSU, you can re-attach drives and boot normally.

Thanks alexoiu and mdd1963.