Maximus VI Formula no longer posts

[tbfleming]

I tapped a key to wake Windows 8 from sleep mode yesterday. It came up then immediately cut power. I haven't been able to get it to come up since.

• ASUS Maximus VI Formula
  
• ASUS GTX 770 DirectCU II OC (2 of these)
  
• i7-4770K @ 3.9 MHz
  
• G.Skill Ripjaws F3-1600C9Q-32GXM
  
• Power: Seasonic X-1250
  
• CPU fan: Cooler Master Hyper 212 EVO
  

Behavior with minimal hardware. I removed all hardware except power, fans, CPU, and RAM, and tried to use the built-in video:

• Powers on, stops with code 79, no video. vga_led is on.
  
• After a few seconds powers itself off then back on
  
• Stops with code b2. No video signal. vga_led is on.
  
• Sometimes, after a couple minutes, it cycles power off then on then repeats starting from the first step
  

Behavior with 1 GTX card plugged in:

• Powers on, stops with code 79, no video. vga_led is on.
  
• After a few seconds powers itself off then back on
  
• Powers on, stops with code 79, no video. vga_led is on. (same as first time)
  
• After a few seconds powers itself off then back on
  
• Stops with code 9c. boot_device_led is on. Onscreen says to press DEL or F2 to enter BIOS, but keyboard is dead. I've tried with 2 different keyboards and tried all 4 USB 2.0 jacks in the back.
  
• Sometimes, after a couple minutes, it cycles power off then on then repeats starting from the first step
  

I reflashed the BIOS, cleared CMOS, tried memOK, and reseated the CPU. None of these helped. I tested both keyboards with another machine; they're OK.

Since both USB and onboard video are dead my guess is either the MB or the CPU went bad. I don't have any other haswell systems to swap components with to test.

[tbfleming]

Any ideas? Is there a way to isolate which component is the problem without buying spare components?

[Chino]

Welcome to the ROG forums, tbfleming.

Have you taken out the CPU to inspect the socket for any bent or missing pins?

[HiVizMan]

My take on this is that the CPU has moved on. Now what might be the cause I do not know.

PSU is most likely to be on my list of suspects, but processors can and do just die mate.

[tbfleming]

I inspected the socket; it looks fine.

I just took a gamble; I bought another i7-4770K locally and tried it. I didn't return the processor under warranty because I once let AI Suite III apply its automatic overclock and overvolt. It's behaving exactly the same. Gamble lost.

[Chino]

1. Put the motherboard on top of the box that it came in and remove all your components and disconnect every cable.
2. Remove the CMOS battery for 10 minutes.
3. Press the Start button to discharge any remaining power.
4. Insert the CMOS battery back into place.
5. Install your CPU with its stock heatsink.
6. Insert one stick of RAM into the DIMM_A2 slot.
7. Connect the 24 pin, 8 pin and 4 pin power cables.
8. Power up your system with the Start button.

Any changes?

[tbfleming]

I had to remove the armor to get to the battery. I removed the mPCIe Combo II card this time. No changes. I even tried different sticks in DIMM_A2.

Chino wrote:
1. Put the motherboard on top of the box that it came in and remove all your components and disconnect every cable.
2. Remove the CMOS battery for 10 minutes.
3. Press the Start button to discharge any remaining power.
4. Insert the CMOS battery back into place.
5. Install your CPU with its stock heatsink.
6. Insert one stick of RAM into the DIMM_A2 slot.
7. Connect the 24 pin, 8 pin and 4 pin power cables.
8. Power up your system with the Start button.

Any changes?

[Chino]

1. Download the 0804 BIOS from Asus website.
2. Format a USB pendrive to FAT32.
3. Extract the BIOS file and rename the file to M6F.CAP.
4. Put the BIOS file on your USB pendrive.
5. Connect the USB pendrive to the the USB port that's right below the USB BIOS Flashback button.
6. Press the USB BIOS Flashback button for three seconds until the LED begins to blink, then release.
7. Wait until the LED stops blinking.
8. Power on your system.

[tbfleming]

I tried this before, but I repeated it now just in case. No change.

Chino wrote:
1. Download the 0804 BIOS from Asus website.
2. Format a USB pendrive to FAT32.
3. Extract the BIOS file and rename the file to M6F.CAP.
4. Put the BIOS file on your USB pendrive.
5. Connect the USB pendrive to the the USB port that's right below the USB BIOS Flashback button.
6. Press the USB BIOS Flashback button for three seconds until the LED begins to blink, then release.
7. Wait until the LED stops blinking.
8. Power on your system.

[Chino]

Disconnect the 8 pin and 4 pin power cable leaving just the 24 pin power cable connected. Press the Start button. Did the fan for the stock heatsink spin up?