Question Installed new CPU, no display or video

[dsitnick]

I just got a new CPU. I replaced it, turned on power, and saw that while the PC stayed on for ~20 seconds with fans/leds running, there was no video coming from the GPU or the motherboard video outputs (HDMI and VGA)

I tried going back to the old CPU, but every time I re-install it and turn on the power, the PC immediately shuts down after powering on.
I am fairly certain that the heatsink is mounted properly, but I am not able to get the original CPU to work now for some reason.

I've tried resetting my CMOS, which does seem to be functional (when I power on after resetting, it reboots brielfy). I've also tried disconnecting everything except for the CPU, power, and 1 stick of RAM but it doesn't seem to have an effect on either CPU.

Also side note, afer resetting my CMOS, the PC no longer powers itself off after 20 seconds (on the new CPU).

I believe my next step would be to confirm whether my BIOS is up to date, but I am not able to work with my old CPU.
Any other ideas? Is the new CPU incompatible? Is it possible that my old CPU can be fixed?

My specs:
Motherboard: Gigabyte Z370 HD3
New CPU: Intel i7-9700K
Old CPU: Intel i3-8350k

Thanks!

 

[jeremyj_83]

I just got a new CPU. I replaced it, turned on power, and saw that while the PC stayed on for ~20 seconds with fans/leds running, there was no video coming from the GPU or the motherboard video outputs (HDMI and VGA)

I tried going back to the old CPU, but every time I re-install it and turn on the power, the PC immediately shuts down after powering on.
I am fairly certain that the heatsink is mounted properly, but I am not able to get the original CPU to work now for some reason.

I've tried resetting my CMOS, which does seem to be functional (when I power on after resetting, it reboots brielfy). I've also tried disconnecting everything except for the CPU, power, and 1 stick of RAM but it doesn't seem to have an effect on either CPU.

Also side note, afer resetting my CMOS, the PC no longer powers itself off after 20 seconds (on the new CPU).

I believe my next step would be to confirm whether my BIOS is up to date, but I am not able to work with my old CPU.
Any other ideas? Is the new CPU incompatible? Is it possible that my old CPU can be fixed?

My specs:
Motherboard: Gigabyte Z370 HD3
New CPU: Intel i7-9700K
Old CPU: Intel i3-8350k

Thanks!

That motherboard only supports the 9th Gen on BIOS Version F11 or later. If you haven't done any BIOS updates before you got the new CPU, odds are you are on the F3 BIOS. Sadly that motherboard doesn't support flashing the BIOS without a CPU installed. Why is it that you cannot use the old CPU?

 

[dsitnick]

That motherboard only supports the 9th Gen on BIOS Version F11 or later. If you haven't done any BIOS updates before you got the new CPU, odds are you are on the F3 BIOS. Sadly that motherboard doesn't support flashing the BIOS without a CPU installed. Why is it that you cannot use the old CPU?

Ah ok, that makes sense. Thank you!

I will keep trying the old CPU until I get it to work, seems like it's my only option. The PC immediately shuts off when I try to use it but it'd be worth applying some new thermal and really making sure the heatsink is properly mounted.

Besides that, I'm not sure what could have caused this issue other than me breaking the CPU while removing it..

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Update: I was able to make absolute sure the heatsink was properly attached and now the old CPU is working. However, the old CPU is now not outputting video either. It seems to power off and restart every 20 seconds.

I've also tried re-installing the GPU, which powers up, but I'm getting no video from there either.