Maximus IX Apex doesn't boot. Q-LED display not powered.

[Subhero]

Hello all,

As the title says it won't boot after returning from a two week vacation. My power was unplugged during my absence. The RGB lighting and the power and reset button light up. The BIOS LED is solid orange, no other LED's are blinking or solid. The q led display is blank, so not even a 00 code is displayed. The PC worked fine for years.

I already unseated and reseated the RAM, CPU. I used the motherboard function to turn off the PCIe slot the GPU is seated in, I already disconnected the storage devices.

The same result with regards to the display.

I bought the MOBO several years ago so I fear for the worst.

[achugh]

Ho @Subhero , it is technically possible that when you connected the power, the spike could have damaged something. To isolate what has gone bad, may I suggest that you disconnect everything, including ram, drives, anything connected to the rear IO etc.

Then when you turn on the computer with nothing but CPU, do you see your Q-LED turn on?

[Subhero]

I disconnected all large components, such as RAM, GPU and my hard drive. I only am not sure about a power cable which says CPU (top left). I think it's an additional power source for the CPU?

On the backside I think some fans are connected but they are damned hard to remove from their pins.

I have still no Q display.

 

[achugh]

Hi @Subhero I am sorry to hear about your troubles and the fact that removing all easily accessible devices did not make any different.

I looked into you manual at https://dlcdnets.asus.com/pub/ASUS/mb/LGA1151/MAXIMUS_IX_APEX/E12404b_MAXIMUS_IX_APEX_UM_V2_WEB.pdf?... and on PAGE 1-29 it says the following

Do not forget to connect the 8-pin EATX12 V power plug. Otherwise, the system will not boot.

---

Is it possible that somehow your PSU port or the cable for this EATX12 V power plugs in the top left corner are not getting any power.

From your picture it seems you only have power connected to EATX12V_1 slot and not to both of them. Also it does not look like you connected any power to EZ_PLUS as well next to your SATA ports.

May I suggest that you move the port on your PSU which is currently connected to EATX12V in the top left corner and give that a try. If switching port does not help, can you try connecting an extra cable to EATX12V_2 as well and see if that helps.

In your manual on PAGE 2-8, it says to connect the 8-PIN Power Plus which you have connected, see below

However, on my board (ROG Z790 DARK HERO) it says to connect 1 or both on PAGE 1-10, see below

It is totally up to you if you want to take a chance of connecting both EATX12V connectors.

I would definitely try removing the cable for connector (which seems like a custom cable as it has GOLD/YELLOW sleeve on it) and then take a regular cable from your PSU and connected it to either 1st or 2nd top corner slot and connect the other end into a new PSU PCI-E port. This will confirm if either this cable or the port on your PSU has gone bad before attempting to connect both the 12V connectors.

Good luck! I hope it is as simple as a bad cable or a port on your PSU and you can get back into a working state quickly.

[Subhero]

Thank you achugh for your expansive reply.

Sadly, I have only one 8 pin connector coming from my PSU so hooking up both won't be possible. I also do not currently own a second PSU to check if the cable is faulty.

I did switch the slot and connected the EZ port however, with no effect.

The system has worked flawlessly with this setup for years so I don't think it's a power demand issue requiring both slots to be connected.

The cables coming from my PSU are embedded btw, I cannot switch them out. Not sure what cable you are referring to being sleeved?

So your suggestion, if I understand correctly, is get a 2d PSU to see if the cable is faulty?

[Nate152]

Hello Subhero

Only one 8-pin cpu power cable is required, if overclocking then connect both.

I suspect either the psu or the motherboard, if it was the cpu, it would display code 00.

Would try another psu, what psu are you currently using?

[dennys2009]

Hay! Try removing the battery that powers the BIOS and turning on the computer without it.

[achugh]

Hi @Subhero please see the GREEN circle I have marked that I was referring in my message above regarding yellow sleeved cable.

Here this cable has a Yellow wire on the LEFT and RIGHT with BLACK cables inside it. I have seen these cables are typically used by YouTube reviewers from suppliers like CableMod Cables. I could be totally wrong here, a typical PSU will only come with a fully BLACK cable. 

So I assumed that you will have the original power cables that came with your PSU. 

You may have some customer builder built this machine for you, in which case I totally get it that you do not have spare cables as you mentioned in your response.

Since you already mentioned that you do not have a spare PSU, do you see any spare 8-PIN cable maybe being used by FANs or some accessory? If you do see an additional cable then you can give that cable a try; in case it is easy to pull it out for this test.

If you have access to a Multi-Meter, these usually have a connection tester (sometimes also shown with a beep symbol). You can then use this connection tester as an option to test all 8-PINS of the cable by connecting 1 point on one end of the cable and the other end into the other end of cable. If the meter beeps then it means that cable out of the 8, does not have a break. You would have to repeat this for 8 times to test all 8 wires one by one. Please note that you need to make sure that you under the PIN layout i.e. number 1 PIN on one side will only beep with the number 1 PIN on the other side. If I were you, instead of looking for a PIN diagram, since all we care about is connectivity, I would pick a PIN on one side and test all the other PINs on the other side to see which one beeps. If more than one PIN beeps then it means this cable is shorted. If none of them beeps then it means this cable is broken. If only 1 PIN beeps then it means this cable PIN is good and I will move on to the next PIN till all 8 pins are tested. In this approach, you may not have to mess your cable management.

Next, if the cable is good, since you have a multi-meter, I will look for a PIN diagram of a PCIe cable and check that 5V PINs are getting 5V by switching the Multi-meter to DC Volts test mode. This will ensure that your PSU is also working, which would then lead to a faulty board.

Lastly, don't forget the suggestion from dennys2009. You can very quickly try and rule if your CMOS battery is the issue by removing it and then try to start your PC. Even without a CMOS battery, the system should start up to make enough progress where the Q-LED should show you something. This is a much quicker test so I will start with this one first.

Good luck!