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i7 4790k won't boot on ASUS B85M-G

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Corey5

New Member
Joined
Apr 3, 2017
Hi there,
I know there have been some threads concerning this mobo and CPU on the internet, but none meets my question a hundred percent. So:
I have an ASUS B85M-G with an I3 4330 and ASUS GTX750ti (will be upgraded soon) as well as 2x Crucial Vengeance 4GB RAM DDR3, 1600Mhz. I know MoBo-Processor-Combination is not the best at all, but a friend of mine gave me his I7 4790k for a few bucks and I know it's compatible. I updated the BIOS to Version 2501 (or something), which is the latest Version from 2015 and brings compatibility to devil's canyon. If I try to boot, there is no "beep" and no boot with the i7. If I change back to the i3 everything works fine. What could be the problem? Is 350 watts ATX to "powerless" (4pin-plug)? Can an ATX with more power (be quiet 550w) give more power to CPU through the 4pin-plug or is the plug limited? I have a really bad and low-budget ATX but want to upgrade to be quiet 550w.

The processor is optically fine and has worked before in my friends PC.
What else can I try? Could there be a problem with RAM-Banks/Slots? I have read something about problems with RAM... In BIOS it shows 1333Mhz, but the Crucial should run on 1600. It is a 1.5V Bank. Could there possibly be a power-problem?

Even without GPU there is no boot.
Would be great if someone has an idea. Thanks a lot. If you need more information, just ask. :)

Regards,
Peter
 
The place to start troubleshooting would certainly be that low quality 350W PSU. The PSU is a foundational component of any build and you should not cheap out on it. The 4790k draws enough additional power compared to he i3 that this could prevent it from starting if the PSU is marginal.

I would also try clearing the CMOS. There should be a 3 pin jumper near the round battery to do this. But before moving the jumper to the clear position, disconnect the PSU from the wall and hit the power button to drain the capacitors. Leave the jumper in the clear position for 30 seconds and move it back to the default position before restoring power.
 
Thanks a lot. I will try it with a BeQuiet 550w PSU. Wednesday (as I hope) I can tell you what happened.
 
It's worth it to swap out another if it's free to test... but at THIS point in trouboeshooting, I wouldn't spend a penny. Let's do the math. 750ti is, at stock, a 60W card. Your new cpu is 88W a difference of around 50W. So.. 88+60+100w for everything else (fans/drives/board) which is woefully overestimating. It should post and get the the bios on that psu...

How about a picture of the label showing all the wattage, etc.

Before I spend a penny, I'd reset the cmos.
 
Yeah, if the PSU is functioning properly ED's math is makes sense. But we don't know if it is functioning properly or even if it actually puts out it's advertised wattage. Cheap PSUs often greatly exaggerate their output and if it's an old unit . . .
 
If volts*ampere=watts, then 12v*15a=180watts. This is too less, right? With your calculation I need 248w:12v=20,6a.

Am I right here?
 
That garbage psu has a total of 30a on the 12v rail(s). Lord only knows if it can output that much though. Still, it should work. The wattage numbers we came u0 with are full 100% load values. That doesn't happen when booting.

Also , please host images here. :)
 
Whether it's causing the boot problem or not, you still need to get a better PSU.

The other thing I would look at is the viability of the CPU itself. You say your buddy gave it to you for a "few bucks." People don't normally do that. Those chips are expensive. Over $300 when new. I would be skeptical of that, especially if the i3 works in the same equipment. I would also check the bios version issue again on the motherboard manufacturer's website. Put the i3 back in and find out what bios version the board is currently running. Then go to the board manufacturer's website and check out which version of the bios afforded Devil's Canyon support.

https://www.asus.com/us/Motherboards/B85MG/HelpDesk_CPU/ According to Asus' website you need bios version 2001 to run the 4790k. If you have an earlier bios version you need to do a flash upgrade to run the 4790k.
 
Thread can be marked as solved. Thank you all. In the end the MoBo had a defect. A pin on the socket was broken so it could "read" the i3, but not the i7. Now I have a new MoBo and the processor works fine with GTX970g1.
Greetz, Peter
 
Glad it's working and thanks for the follow up! You can mark it solved. :)

I'd look I to a new PSU much sooner than later as well... ask us when you are ready to buy. ;)
 
SOLVED

I have also bought a new PSU (Corsair VS 550). How do I close this thread? I only can thank and reply... Seems I am blind... :-/
 
Last edited:
You click on the Go Advanced Button and edit the subject line to say "Solved."
 
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