Question New PC won't post because of "VGA issues" using intel GPU

Jan 27, 2023
I just bought a new PC and got most of the components today and put it together. This is not my first pc as I've put together about 20 but first one in about 7 years.

The motherboard is ASUS Prime Z790-A. The CPU is Intel 13900K. Memory is 128GB Vengence. GFX is Intel A770.

Initially it did not post but I think I might not have seated the memory(I put in one stick first) or put it in the wrong slot(didn't realize that one might have to use specific slots).

Anyways, after a few tries nothing. After a little messing around to see if I missed something(moved the memory around an nothing) and realized that the white light was VGA issues(the labeling on the MB does not align with the LED's so I thought it was some led off to the side) I tried a few hdmi cables and nothing. I don't know exactly what I did but basically I removed the A770 from the system and was trying the built in hdmi port trying to use the CPU's GPU. It would not post. CPU led was fine, DMM was fine... but white light. I tried all the standard stuff and looked online and that but nothing.

I couldn't get it to post for any reason and it was always the white Q_LED. Well, I figured something was bad, cpu or motherboard.

But I went ahead and put the A770 back in since all I could do was retry it and hope that it wasn't the MB and it actually posted and I could get to the BIOS. My HD's are not in yet so not really much to do.

I noticed that in the bios there would be, here and there, a few flickers in the screen(seems to go white for about 100ms) but it didn't happen much and seemed to just happen at the start.

Since I had nothing else to do I decided I should run a mem test to verify my memory so I put in the 3 other sticks(I did mess around in the bios a little just seeing what was different than my previous ASUS but didn't do much). The screen in memtest flickers constantly, about once every 10 seconds.

So given these issues I'm wondering if I have something defected.

  1. It is likely not the A770 but I do hear there are issues with it. It could be just some incompatibility with memtest but given how it did a similar flicker in the bios I think it is more hardware based.
  2. The onboard GPU should have worked. I think once I get an OS installed I can test it out but I'm concerned about not being able to get output. I specifically bought the K just so I could get output in case the A770 went bad but it's failing. I haven't tried the DP connector though.
So either it is either the MB HDMI connector or the CPU. Someone in some post somewhere mentioned that they had a similar issue and it was a connector that wasn't connected but that doesn't make sense in my case as it's a mounted connector(but maybe has a solder joint issue.

The A770 is suppose to have some type of bridging with the intel CPU and GPU which is why I specifically chose the combo as I felt it was good for my circumstances. So in a few days I should get an OS installed and wondering how I can test all the features of the combo and onboard GPU to make sure everything is working the way it is suppose to or if I need to return the CPU.

Is there any programs that can do this kind of testing?

The MB did have a pin bent, it has some splotches on the conformal coating which is odd, and some weird grease like spots on it. Some of the screws for the M2 heatsinks also look used. So I'm not sure if I head a refurbishedboard or not.

Any ideas?

Update: I had a DP to HDMI adapter and just tried it and it worked so it is almost surely the HDMI port on the MB ;/ Although if move the HDMI to the DP poor it doesn't recognize the change. Maybe there is a short or something when connecting the HDMI. This of course doesn't explain the flickering and I haven't checked to see if it still does it using the onboard GPU.
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Bad pin on the motherboard? In the CPU socket, or somewhere else? That alone could be the problem with the iGPU and partially responsible for your other startup issues. The A770 does run off the CPU PCIe lanes as well.

What kind of CPU cooler did you use? Overtightening can also lead to problems.

128GB of memory may also be part of the problem. Getting that much memory working on a consumer board is usually troublesome. Also it hard to conceive of many circumstances that much memory is needed for unless you are doing high resolution video editing, and the like.

Display Port can be finicky about being moved after start up, so I wouldn't rely on that.

Thermal pads can leak out a grease looking spots.

No bridging between the Intel CPU and Arc graphics cards. It is just a different GPU. A770 isn't bad performance wise, though for the money there are better AMD and Nvidia options, but the drivers do have problems with older games. Standout features are fully working AV1 encoding, XeSS, and all modern I/O, and a decent amount of VRAM.

If you were thinking of Resizeable BAR, AMD and Nvidia also support those. For Intel it is basically mandatory. Which is something you should look into by the way, make sure you get that enabled.

Expect glitches. I myself am trying out the A380. #1 complaint is failure to detect HDMI audio devices when it should. Have to constantly disable/enable the HDMI audio driver to get it working.
Jan 27, 2023
Using an AIO. I did tighten it down with a screw driver then backed off a bit(I did it by finger tight but then tightened it down a little bit then backed off a little.

Intel says the A770 will bridge with the onboard GPU to provide a boost in performance.
"Intel® Deep Link is Intel's innovative platform that combines the power of both the integrated and the discrete GPUs. "

Of course IIRC opencl will allow use combining multiple GPU's too but I think deep link is able to combine them more naturally in hardware. It may be only for certain types(encoding) but that was the point of spending an extra 20 for the K over the KF.

I doubt the memory will be an issue and I will use some of it for a ramdrive(and so if it is an issue as long as I can use it for a ram drive to limit it then it will be fine). I'm not really a gamer and use a wide range of apps(gfx, engineering, video editing, programming, etc) so wanted something that could keep up. Didn't feel like spending 4x for 4x the card even though it might have been more efficient. I felt the 4090 was just 4 cards in one and one is mainly buying 4 cards. Even though it has some nice features I mainly wanted something that was good enough and I think the A770 might be(it should be 4-5x faster than what I have).

The main thing about the hdmi on the MB is: 1. if it's pointing to a quality issue with the CPU or MB(which means I'll have to return it). 2. I could do without the hdmi connector since at least the DP works. as the A770 has 4 + 1 DP. That would give me 6 monitors rather than 7 and I'm ok with that(I used around 4-5 but can get away with 4). But if it i's a more serious issue then I'll need to send something back and I don't really know which at this point. Since I haven't got an OS to install yet I don't know if there are other issues. I also don't know how well the A770 is going to behave. I read it had glitches but that it was mainly issues with games which, since I'm not a gamer, I don't have to worry about.

I mainly got the A770 for deep link, 16GB, and encoding. I think that will do what I need and in the future I can always upgrade if the price is right. I felt, for the most part, I was buying about 1/4 of a 4090. I was getting some of the newer features but wasn't making such a risky investment. It would allow me to get a few better things such as more memory, better SSD's, etc. As long as the issues with the card is mainly superficial and can be fixed with drivers then I'll probably be ok with it. One thing I can't have is it flickering every few seconds or issues with resolution but I think driver updates should fix those.

So, right now everything seems to be working except the hdmi port. If that is it I'll probably just accept it and be fine.