Question Black Screen After Upgrading to i7-4790K

ZorakXT

Honorable
Jan 3, 2015
16
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10,525
I bought a new sealed i7-4790K off of eBay, and switched out my old i5-4690K. Unfortunately, when I booted the computer up, despite all the fans and LEDs turning on, there seems to be no output to my monitor, keyboard, mouse, or speakers. After a few seconds it will reboot and remain like that.

Steps of install:
  • Switched off power and unplugged PSU.
  • Removed cooler (Hyper 212X Turbo).
  • Cleaned off old thermal paste off of old CPU and cooler with rubbing alcohol.
  • Switched the CPUs (it fit perfectly and is compatible with my motherboard [MSI Z97 Gaming 7]).
  • Applied a rice sized drop of thermal paste to CPU.
  • Secured cooler back onto CPU, tightening in the pattern shown in the manual.

Once I booted up however there seemed to be no output to my connected devices despite the fans and LEDs coming on.

I reinstalled my old CPU and it works fine. In addition I tried these steps to correct the problem but none have worked so far:
  • Removed battery for 30 seconds and replaced it.
  • Pushed the CMOS button on the back for 5 seconds.
  • Updated to latest BIOS.
  • Restored BIOS settings to optimal default.
  • Plead and begged it to work.
  • Switch the DisplayPort cable to the motherboard instead of graphics card.
  • Removed and replaced RAM.

Specs:
Motherboard - MSI Z97 Gaming 7
PSU - Corsair CX750M
CPU - i7-4790K
RAM - Corsair Vengeance 16GB
OS - Windows 8.1
GPUs - GTX 980 SLI

Does anyone have any ideas on what else I can try or is it just a DOA? Thanks.
 
Despite it seeming new/sealed, there are many unscrupulous types on EBay that will sell whatever/anything with a newly marked heatspreader on top...

You mentioned trying onboard graphics, but, did you remove the two GPUs, freeing up at least 300-400 watts of startup load from PSU? If still no display, it would sure seem the CPU is dead, and, I'd suspect fraud long before suspecting an bonafide dead cpu right out of the box... (Look closely for signs of a non-factory applied heat spreader, and, examine CPU's underside carefully against photos of known legit CPUs....; there are often clues and small visual differences from one cpu to the next...
 
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ZorakXT

Honorable
Jan 3, 2015
16
2
10,525
Despite it seeming new/sealed, there are many unscrupulous types on EBay that will sell whatever/anything with a newly marked heatspreader on top...

You mentioned trying onboard graphics, but, did you remove the two GPUs, freeing up at least 300-400 watts of startup load from PSU? If still no display, it would sure seem the CPU is dead, and, I'd suspect fraud long before suspecting an bonafide dead cpu right out of the box... (Look closely for signs of a non-factory applied heat spreader, and, examine CPU's underside carefully against photos of known legit CPUs....; there are often clues and small visual differences from one cpu to the next...
Thanks for the reply. All the packaging and original seal seemed to be intact and everything inside looked legit. Was able to get the seller to accept a return.