Breadboarding no display : dead CPU ?

[artecnoir]

Hello there,

My computer had a problem for a while : when I was trying to start it, it was restarting 30 times before actually booting. Until one day it didn't boot at all and kept rebooting infinitely.

I didn't know where the problem came from, so I removed one by one all the components of my computer. I eventually breadboarded the computer (PSU + Motherboard + CPU) alone and the problem was still here.

I tested my PSU with a multimeter and everything looked fine. I also tried to breadboard my computer with another PSU and the problem was still here so I think my PSU is okay.

I tried to remove my CPU and start the motherboard alone : problem was still here. So I thought my motherboard was dead and I just had to replace it.

Today I received a new motherboard and actually it doesn't work better!
When I breadboard my new motherboard + PSU + CPU the system launches, reboot after five seconds, and then seems to launch correctly (I don't know since I have no display)

BUT When I breadboard my new motherboard + PSU + CPU + RAM + HDMI Screen it acts the same, and I have absolutely no display. I tried several RAM slots.

I begin to think that in fact my CPU is dead which would explain the infinite restarting loop problem, and the fact I have no display now. But I have no speaker in my case and after all these unsuccessful tries I'm a bit confused and unsure of my conclusion.

Do you have some advices for me ?

Thanks in advance,
Martin

 

[Barty1884]

Please post your full system spec.

 

[artecnoir]

Intel Core I7 4790K
ASRock B85M (new motherboard)
GSKILL Ares Low Profile 16 Go (4x4 Go) DDR3 2133Mhz Cas 10
Radeon R9 280 Dual-X OC
PSU : Be Quiest System Power S7 600W 80+Silver

 

[Barty1884]

I'd probably be more inclined to look to a memory issue, opposed to a dead CPU. While it's possible, CPUs are either (generally) DoA, or have had substantial voltage pushed through them.

Try CPU + Mb + 1x RAM module + relevant PSU connectors.
What happens then?

FWIW, you removed the CPU and tried to boot with just the MB + PSU? That's not going to help diagnose anything whatsoever.

 

[artecnoir]

Unfortunately yes, I tried CPU + MB + 1x RAM module (several times in different combinations) and :

On my new MB : No screen, System reboots once after 5 seconds and then fans keep spinning (still no screen)
On my old MB : No screen, System reboots every 5 seconds infinitely

 

[Barty1884]

The new motherboard..... is it new/old stock?

The B85M at launch didn't support the 4790K ,as that's Devil's Canyon/Haswell Refresh....So needs a BIOS update.
https://www.asrock.com/mb/Intel/B85M/#CPU

Doesn't explain the issue with the original board though.

Entirely possible it's the CPU, but without testing the board(s) with another, known working/compatible CPU, it's going to be hard to say with certainty.

 

[Twistfaria]

Try using some other connector for your video out like a DVI or VGA. HDMI on some motherboards will need an appropriate driver before outputting. Does your motherboard not have a speaker? Tiny thing with two wires and a little speaker the size of a gum ball that plugs in to the same area that all the case buttons plug. These ideas come from this checklist, you should run through the whole thing: http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

 

[artecnoir]

The new motherboard..... is it new/old stock?

The B85M at launch didn't support the 4790K ,as that's Devil's Canyon/Haswell Refresh....So needs a BIOS update.
https://www.asrock.com/mb/Intel/B85M/#CPU

Doesn't explain the issue with the original board though.

Entirely possible it's the CPU, but without testing the board(s) with another, known working/compatible CPU, it's going to be hard to say with certainty.

Wow I absolutely didn't think about the CPU support, that's a great insight.
The exact version of the motherboard is ASRock B85M DASH/OL R2.0, I'm trying to find the BIOS version.
I should be able to get an used i7 4770 next week to do some tests and see if it works

 

[Barty1884]

If you can get ahold of a 4770 to test (without an additional cost), it's certainly worth a try.
Maybe the old board was dead, and the new board has an older BIOS revision..... It's certainly a possibility.

 

[artecnoir]

Try using some other connector for your video out like a DVI or VGA. HDMI on some motherboards will need an appropriate driver before outputting. Does your motherboard not have a speaker? Tiny thing with two wires and a little speaker the size of a gum ball that plugs in to the same area that all the case buttons plug. These ideas come from this checklist, you should run through the whole thing: http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

Thanks for the suggestions, actually I tried with DVI and it didn't work but I can try with the VGA if I manage to find a VGA cable.
Unfortunately there is no speaker in my case. I will check this checklist though !

 

[artecnoir]

If you can get ahold of a 4770 to test (without an additional cost), it's certainly worth a try.
Maybe the old board was dead, and the new board has an older BIOS revision..... It's certainly a possibility.

Indeed, I will try this and post an update next week !
Thanks much for the help.

 

[artecnoir]

So I could test with a 4770K and everything worked perfectly on my new motherboard.
I also tried 4770K on my old motherboard and the computer kept rebooting.

So I flashed my new motherboard and tried my 4790k again but again nothing appears on screen so I can conclude both my old motherboard and my 4790k are dead unfortunately.

I don't know why both components died at the same time but it explains all the difficulties I had to diagnose the problem.