Intermittent 1xlong, 3xshort beeps, and white LED on PRIME Z490-A

[JamesAndersonJr]

Hello, Everyone!


I'm having an issue with my new motherboard (ASUS PRIME Z490-A) I just purchased last month from TechINN, the only e-tailer which still sold it online at the time of purchase (12-15-2021).


The Issue: Sometimes the computer beeps once indicating a successful POST. Then seconds later I hear 1xlong + 3xshort beeps and the white LED on the motherboard near the RAM lights up. This has happened with and without a dGPU installed. Though it is intermittent, and sometimes the beeps don't occur, and I can access the BIOS (only from the iGPU. I NEVER could access the BIOS from the dGPU, whether or not I got the beeps). Despite the beeps, the computer sometimes continues booting and the monitor first comes on when the PC reaches the Windows 11 log-in screen. So it seems as though the Windows 11 OS sees the dGPU (EVGA GTX 750 Ti, 2GB GDDR5) fine, but the BIOS does not recognize it at all (i.e., no image until the OS boots up). At first, I thought this must be because my GPU is just way too old, but I experienced the series of beeps also when no dGPU was even installed and the monitor was driven entirely off my Core i9 10900K CPU! So if anyone can tell me if it's an incorrect BIOS setting, or do I just need to send my motherboard back to ASUS for repair or replacement (if, it is still even under warranty). Thank you all kindly for your help in advance.


In BIOS (with dGPU Installed, but DisplayPort cable from my monitor plugged into iGPU DisplayPort), here are my settings:


Primary Display: Auto
DVMT Pre-Allocated: 64M
RC6(Render Standby): Enabled
PCIEx16_1 Link Speed: Auto
PCIEx16_2 Link Speed: Auto

[STARRAIN_ROG]

Hi JamesAndersonJr,
Do you only use 1 monitor?
May I know why don't you connect to dGPU with DP?
Please refer to the following link to check the CPU and VGA part.
https://www.asus.com/support/FAQ/1042678
Does it occur on bios 2403 with bios all default settings?
If yes, please enable CSM and then try again.
Thank you.

[JamesAndersonJr]

STARRAIN@ROG wrote:
Hi JamesAndersonJr,
Do you only use 1 monitor?
May I know why don't you connect to dGPU with DP?
Please refer to the following link to check the CPU and VGA part.
https://www.asus.com/support/FAQ/1042678
Does it occur on bios 2403 with bios all default settings?
If yes, please enable CSM and then try again.
Thank you.

Yes, only My ASUS TUF Gaming VG259QM 24.5" Monitor (Connected to EVGA 750 Ti 2GB via Displayport)
The only reason I don't connect the dGPU to the Monitor is that I can't access the BIOS via the dGPU, and the first sign of life is after Windows 11 boots.
Yes, it occurs with BIOS 2403 (I recently installed it).
About to try to enable CSM, but I don't want SGX not to work because I play 4K Blu-Rays with CyberLink PowerDVD 21 and I think I remember them saying CSM has to be disabled, and the PC has to be booted in UEFI mode. But I will try and report back what I find.

[JamesAndersonJr]

YEEEEEEESSSSSS!!!!! Enabling the CSM did the trick!!! But now I have (4) Questions:

1.) How did you know the issue was related to the CSM?

2.) What does the fact that the issue was solved by switching on the CSM say about the motherboard or GPU?

3.) Will Software SGX still work for CyberLink PowerDVD 21 4K UHD Blu-Ray playback with the CSM switched on?

4.) Is Windows 11 still able to boot in UEFI Mode?

[STARRAIN_ROG]

Hi JamesAndersonJr,
It is might be dGPU or monitor related.
If when hear the beeps and white qled light on, you still can boot into windows and show the display, please turn on your monitor and then turn on your pc to check again with CSM disabled.
When CSM enabled, it would detect all the components to improve compatibility, and detect the dGPU and the monitor at first.
However, there is [UEFI only] option to boot in UEFI mode with CSM enabled.
Thank you.

[JamesAndersonJr]

I recently had to turn off (i.e., disable) the CSM, because when the CSM is enabled in the BIOS, the Samsung Magician SSD utility will not load and refuses to launch in the OS (Windows 11 Pro 64-Bit).

I ruled out the dGPU as the source of the beeps though, because I just recently purchased and installed a brand new EVGA GeForce RTX 3060 Ti XC Gaming, 08G-P5-3663-KL, 8GB GDDR6, Metal Backplate, LHR graphics card (directly from EVGA), and the problem still persist while using the only DisplayPort on the new dGPU. I then tried using one of the three HDMI ports on the dGPU, and though I didn't experience any beeps or white QLED (possibly from not being connected that way long enough...remember, intermittent), I didn't like the image quality and lower bandwidth of HDMI 2.0 vs. DisplayPort 1.2 (the max version of DP my monitor will support). So, I switched back to using DisplayPort again.

The other two things I tried to resolve the beeps and white QLED are (1) turning VRR on from my monitor's OSD while still in BIOS, and (2) turning off "Fast Boot" in BIOS. Though, I'm not quite sure if either of those steps really helped anything (the beeps and the white QLED seemed to occur less, but that could be just a placebo effect...so, not really sure).

Another problem I think (not certain) I'm having with my PRIME Z490-A is that audio from the rear lime green speaker port seems to randomly fade slightly in and out (i.e., quieter, then louder) intermittently. Now, this may technically be simply flawed hearing from my imperfect 37 y.o. ears or yet another sign of a possibly bad motherboard. Right now, it's not obvious enough to know based on hearing alone.

If I don't get these issues resolved soon, I will have no other recourse but to call ASUS Motherboard support for a possible RMA request.

But, any help I can receive before I'm forced to move on to that step would be greatly appreciated.

Thanks in advance!

[JamesAndersonJr]

I recently had to turn off (i.e., disable) the CSM, because when the CSM is enabled in the BIOS, the Samsung Magician SSD utility will not load and refuses to launch in the OS (Windows 11 Pro 64-Bit).

I ruled out the dGPU as the source of the beeps though, because I just recently purchased and installed a brand new EVGA GeForce RTX 3060 Ti XC Gaming, 08G-P5-3663-KL, 8GB GDDR6, Metal Backplate, LHR graphics card (directly from EVGA), and the problem still persist while using the only DisplayPort on the new dGPU. I then tried using one of the three HDMI ports on the dGPU, and though I didn't experience any beeps or white QLED (possibly from not being connected that way long enough...remember, intermittent), I didn't like the image quality and lower bandwidth of HDMI 2.0 vs. DisplayPort 1.2 (the max version of DP my monitor will support). So, I switched back to using DisplayPort again.

The other two things I tried to resolve the beeps and white QLED are (1) turning VRR on from my monitor's OSD while still in BIOS, and (2) turning off "Fast Boot" in BIOS. Though, I'm not quite sure if either of those steps really helped anything (the beeps and the white QLED seemed to occur less, but that could be just a placebo effect...so, not really sure).

Another problem I think (not certain) I'm having with my PRIME Z490-A is that audio from the rear lime green speaker port seems to randomly fade slightly in and out (i.e., quieter, then louder) intermittently. Now, this may technically be simply flawed hearing from my imperfect 37 y.o. ears or yet another sign of a possibly bad motherboard. Right now, it's not obvious enough to know based on hearing alone.

If I don't get these issues resolved soon, I will have no other recourse but to call ASUS Motherboard support for a possible RMA request.

But, any help I can receive before I'm forced to move on to that step would be greatly appreciated.

Thanks in advance!

[STARRAIN_ROG]

Hi JamesAndersonJr,
May I double confirm you get 1xlong, 3xshort beeps, and white Q-LED when connecting dGPU via DP every time? Or it is intermittent?
Although you get 1xlong, 3xshort beeps, and white Q-LED, there is no ROG LOGO while POST and you cannot enter bios via pressing F2 or DEL but you can see the win11 log-in screen?
Have you tried with other DP cable and other monitor?
Thank you.

[JamesAndersonJr]

STARRAIN@ROG wrote:
Hi JamesAndersonJr,
May I double confirm you get 1xlong, 3xshort beeps, and white Q-LED when connecting dGPU via DP every time? Or it is intermittent?
Although you get 1xlong, 3xshort beeps, and white Q-LED, there is no ROG LOGO while POST and you cannot enter bios via pressing F2 or DEL but you can see the win11 log-in screen?
Have you tried with other DP cable and other monitor?
Thank you.

It's intermittent. It happens most often during a soft restart (from within Windows). At least with the new EVGA 3060 Ti, I can access the BIOS with DP or HDMI cable plugged directly into the dGPU, whereas with the old 750 Ti it would never allow me into BIOS while plugged into the dGPU.

Yes, you can tell when it's going to happen in this way: My monitor's power indicator LED is orange for standby, and white for on. When it's going to happen, during the initial "successful post" beep the monitor LED stays orange despite the successful post beep, then seconds later I get the 1xlong, 3xshort beeps, and white Q-LED. However, when it is not going to happen, during the initial successful post beep the monitor power indicator LED nearly instantaneously turns from orange to white, and the ASUS BIOS logo shows on the screen, and everything is fine.

I have only the original DP cable that came with the monitor (that I'm currently using), and some Cable Matters DP cables that cause screen flickering at 144Hz+.

[STARRAIN_ROG]

Hi JamesAndersonJr,
Thank you for your reply.
If it only occurs when connecting to dGPU, please also consult EVGA to see if there is any firmware update for the issue.
Thank you.