PC won't turn on after changing the processor

[AlbertoTomm]

Good morning everyone. I recently upgraded my pc with new components: a GeForce GTX 1650 graphics card (D6 VENTUS XS OC) and a new Intel I5 9400F processor. I installed the processor by disassembling the old one, but I think it is not compatible with the motherboard which is quite old, because the pc gave no signs of life. So I put the old processor back in (without putting in thermal paste because I had not bought it, because the new processor already had it pre-applied) and it started working again. I then put in the graphics card and the pc kept going. I saw on a forum that the processor compatibility could be due to the Bios not being updated, so I updated it by downloading the latest update. So I put the new processor (the I5) back in and it wasn't giving any signs of life (but I don't really care about that now). The problem is that putting the old processor back in, the computer fans turn on, however, the pc does not turn on. In addition, I think the motherboard is not among those that make the diagnostic beeps, because I have for example removed the ram and it does not make any beeps. I disassembled and reassembled the processor one more time and the pc turned on, then I waited a while and tried again and it wouldn't turn on (only the fans turned on). I tried several times to take it apart, but nothing. The processor, however, gets hot. I also tried taking the battery out and putting it back in, but nothing, and I also changed the power supply to the only other one I had (from a case).

The pc was a pre-assembled Asus and the pc components are:
- motherboard K31CD-K
- processor (old): seventh-generation i3
- graphics card (old): gtx 720
- ram 4 GB
- Storage 1TB SSD Samsung 870 Evo (which I put some time ago).
(I can't be very specific because I don't remember the specs and I can't see them because the pc doesn't work)
The pc is the same, but with some differences in hardware, as this one: https://www.esseshop.it/pc-asus-k31cdkit013t-p-82556.html
I premise that I am not an expert in pc assembly.
Thank you very much.

Some pictures (old processor):
https://ibb.co/F80vP4c
https://ibb.co/NSjCMcW
https://ibb.co/mvJzFYK

 

[Jerry James]

Good morning everyone. I recently upgraded my pc with new components: a GeForce GTX 1650 graphics card (D6 VENTUS XS OC) and a new Intel I5 9400F processor. I installed the processor by disassembling the old one, but I think it is not compatible with the motherboard which is quite old, because the pc gave no signs of life. So I put the old processor back in (without putting in thermal paste because I had not bought it, because the new processor already had it pre-applied) and it started working again. I then put in the graphics card and the pc kept going. I saw on a forum that the processor compatibility could be due to the Bios not being updated, so I updated it by downloading the latest update. So I put the new processor (the I5) back in and it wasn't giving any signs of life (but I don't really care about that now). The problem is that putting the old processor back in, the computer fans turn on, however, the pc does not turn on. In addition, I think the motherboard is not among those that make the diagnostic beeps, because I have for example removed the ram and it does not make any beeps. I disassembled and reassembled the processor one more time and the pc turned on, then I waited a while and tried again and it wouldn't turn on (only the fans turned on). I tried several times to take it apart, but nothing. The processor, however, gets hot. I also tried taking the battery out and putting it back in, but nothing, and I also changed the power supply to the only other one I had (from a case).

The pc was a pre-assembled Asus and the pc components are:
- motherboard K31CD-K
- processor (old): seventh-generation i3
- graphics card (old): gtx 720
- ram 4 GB
- Storage 1TB SSD Samsung 870 Evo (which I put some time ago).
(I can't be very specific because I don't remember the specs and I can't see them because the pc doesn't work)
The pc is the same, but with some differences in hardware, as this one: https://www.esseshop.it/pc-asus-k31cdkit013t-p-82556.html
I premise that I am not an expert in pc assembly.
Thank you very much.

Some pictures (old processor):
https://ibb.co/F80vP4c
https://ibb.co/NSjCMcW
https://ibb.co/mvJzFYK

Yes, that motherboard isn't compatible with your new CPU. Your current board uses an H110 chipset, which only supports 6th and 7th Generation Intel Core processors (6000 and 7000 series).

As for your issue with the old CPU, did you apply thermal paste? If not, your CPU will just immediately throttle and shut itself off to prevent permanent damage. Please don't run it if you haven't applied paste after disassembling. You have to remove the old paste (99% IPA solution makes this super easy) from both the cooler and the CPU and then apply a pea-sized dot of new paste onto the CPU.