Can't get ROG Maximus z790 Apex to recognize Old Graphics Card for debugging

[OldGuy17]

Sorry for the long post, but I want to ensure that you have all the info you might need in order to help me with this issue.

Looks like the BIOS shipped with my new ROG Maximus Z790 Apex does not recognize an old (15 yrs) Diamond Radeon HD4890 graphics card (with dual DVI monitor interfaces, and whatever version of PCIE was common back in 2009): After pushing the Start button on the MB, I get a long (about 1-2 minutes) succession of Q-Codes ending in a D6, with a painfully bright white LED shining just above the 2-digit 7-segment displays near the Start button on the MB.

System specs as currently configured:

MB: ROG Maximus Z790 Apex

CPU: Intel Ultra 9, 285K. Heatsink: BeQuiet! Pure Rock Pro 3. Both CPU fans, and all chassis fans are running properly.

Main Nonvolatile Storage: Samsung 900 2-TB SSD (with integrated heatsink; not using heatsink that came with MB) in the main M.2 slot

RAM: G.SKILL Ripjaws DDR5, 64 GB (2x32GB), in the only 2 RAM sockets on the MB.

Power Supply (PS): BeQuiet! Straight Power 12-1000. Fan runs properly.

Graphics Card (for temporary configuration and debug purposes only): Diamond Radeon HD4890. Fan runs properly, and the two 6-pin connectors on the "VGA1" power circuits from the PS are plugged into the corresponding two 6-pin connectors on the Radeon card. (I also have an Alienware desktop, circa 2012, with 2 GeForce 760 Ti cards. Might I have better luck avoiding the D6 error by replacing the Radeon card with one of those? They also pre-date DisplayPort, and have DVI connections to the monitor.)

Monitor: Samsung B245. Connected to Radeon card via DVI cable. (Monitor stills works well, but DVI and the old 15-pin VGA are the only ways to connect to it.)

I am using the Radeon card (and my old monitor) just to debug the motherboard installation before installing an ASUS GeForce RTX 5070Ti, and connecting that graphics card to a new ASUS monitor via DisplayPort.(Based on my experiences with computers over the past 40+ years, things generally end up working best when I don't try to use all-new components all at once).

My question is this: Is there any hope that I can get this MB to recognize and work well enough with the Radeon card to configure the BIOS, test the RAM and SSD, install Win 11 Pro, and address any lingering Q-Codes indicating other problems, before I integrate the new graphics card and monitor into the build? If so, please suggest actions I might take to make that happen. If you are certain that I cannot make this work without heroic measures, is there a known issue with my MB that prevents it from finding old graphics cards? In that case, I guess I'll have to install the 5070Ti and the new monitor, to see if those replacements will avoid the D6 failure while also not introducing more errors.

Thank you for any help you can provide!

[OldGuy17]

Sorry! My MB is actually a Z890, not a Z790. So, I think my post may be in the wrong area. I will repost in Intel 800 forum.

[JohnAb]

I don't really understand. Why test with such an old GPU when you have a 5070TI available? I would just use that from day 1. I'm not being unkind, I just can't see any advantage in your approach, but if I'm missing something I'd be happy to learn more. You have explained that you are worried about using new components all at once, but I really don't think you should be concerned. 

[OldGuy17]

Hi JonAb,

I'm over in the Z890 forum now, but I just wanted to update you on status.

I ended up having to just try to use all 3 of the brand new devices I purchased from ASUS, and to debug their interactions all at the same time.

Currently, the brand new 5070Ti card is never recognized by the Maximus MB, and the ROG Swift PG32UQXR never sees any signal from the 5070Ti.

Nothing suggested by the moderator of the Z890 forum has helped to isolate the problem to the 5070Ti, the MB, or the monitor.

So far, I'm pretty disappointed with ASUS and their lack of post-purchase support: those 3 ASUS products, which I would have thought would have worked well together, don't, and I now have about $2500 worth of MB, graphics card, and monitor that are useless. Hopefully, I will eventually get some useful suggestions about how to isolate the issue(s) (which will be difficult for the 5070Ti, since I do not have another MB that would have a prayer of recognizing that card).

So, this is exactly why I wanted to bring up the new system, adding one new (unknown-good-or-bad) component at a time. Unfortunately, unless there is a way to force the MB to use the iGPU resident on the Intel Ultra 9 285K without being able to interact directly with the BIOS, I'm not exactly sure how I'll proceed at this point.

[JohnAb]

OK, understood thanks and thanks for the update. Somebody said just the other day that connecting the GPU via the HDMI port might get you an initial signal (when it should be saying press F1 to enter BIOS). I don't know if that will help you, but worth a try. Another thing will be to set the PCIe bus for the GPU to gen 4. That has helped people with Z690 and 50xx cards at least. 

Also, try posting in the ROG Care section of this site, hopefully you will get some help that way but I feel your disappointment.