PC wont BOOT with RTX 3080ti and HDMI to TV

Ej24

Gawd
Joined
Jun 11, 2016
Messages
628
Finally got my hands on an RTX 3080ti at MSRP to replace my 1080ti annnd its immediately being weird.

The issue:
PC that previously worked fine with 1080ti, upgraded to new 3080ti will not POST if i connect it to my LG OLED TV via HDMI.
If I connect to a random Dell pc monitor via the exact same HDMI cord and port on the gpu, its fine.
With the 3080ti installed trying to boot connected via HDMI the motherboard goes through the POST code LEDs and stops on "BOOT" LED.
Usually this indicates no bootable device. Swap out the 3080ti for the old 1080ti, boots up while connected to the TV by HDMI no problem.

System:

  • TUF GAMING Z690-PLUS WIFI D4 (BIOS 1304)
  • i7-12700k
  • 32GB Gskill trident Z RGB
  • WD SN850 2TB Pcie 4.0 SSD
  • Previously EVGA GTX 1080ti Black
  • Now Asus ROG Strix RTX 3080ti
  • Corsair RM850x PSU w/ 3 separate 8-pins to GPU
  • Windows 10 21H2

Displays:
  • LG OLED 55B7A TV (from 2017ish)
  • Dell something..27in 1080p generic office monitor

I've tried:
  • Updating BIOS
  • Updating the GPU Bios (its already on latest according to Nvidia tool)
  • Downgrading drivers to recommended version from ASUS
  • Upgrading drivers to latest
  • Total Clean install of drivers to latest
  • Reset motherboard bios to defaults
  • manually set PCIE slot to gen 3, gen 4, gen 5, auto
  • set default display output in BIOS to PCIE graphics instead of auto
  • many, many HDMI cables

If I boot the 3080ti connected to the Dell monitor and add the TV after via HDMI, its fine. Remove the monitor and it'll happily run connected to just the TV. That's not a viable solution though.
It will boot with the 3080ti plugged into nothing, then plug in the TV via HDMI after its booted. Again, don't really want to plug and unplug my HDMI every time.
I also tried connecting to the LG TV using a Display Port 1.4 to HDMI 2.0 adapter such that the HDMI from the TV is connected to the DP port on the 3080ti, and it boots up fine, though scaling is now a weird mess.
The 3080ti has passed every test I could throw at it while connected to the Dell monitor, and the TV if I do one of the above workarounds, so it does indeed work.

Is there some weird handshake with the newer revision of HDMI on the 3080ti not getting along with the LG TV?
I suspect thats not something that would interfere with BOOTING.
Again, to be clear the system is not booting with HDMI to TV, this is definitely pre-OS issue, so it shouldn't be a driver thing.

Asus tech support was not immediately helpful. They asked if my TV was powered on...

Should I just return the thing and try again?
Or is there a chance my motherboard is the cause?
 

lopoetve

Fully [H]
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Oct 11, 2001
Messages
32,692
JayZ2cents just had a thing on this. Might need another box to do a DID update on it, or use the Dell monitor. Something. I was drunk when I watched the youtube video.

 

toast0

[H]ard|Gawd
Joined
Jan 26, 2010
Messages
1,876
Asus tech support was not immediately helpful. They asked if my TV was powered on...

I've got some iGPU computers that won't power on if connected to one of my tvs when it's turned off; so it might be a less dumb question than you think? Will turn on fine if the TV is on (or if the hdmi cable isn't plugged in), so I just live with it. IIRC, turning the TV on after the computer doesn't work either.
 

Ej24

Gawd
Joined
Jun 11, 2016
Messages
628
JayZ2cents just had a thing on this. Might need another box to do a DID update on it, or use the Dell monitor. Something. I was drunk when I watched the youtube video.


Wow interesting, good find! It seems that issue pertains to Displayport though. I used the Nvidia tool to update the Display ID firmware but it said my gpu is already up to date. Jay mentions, the issue could be between gpu *and* motherboard so perhaps my motherboard UEFI is somehow in conflict with the updated gpu Display ID firmware in the gpu now. I guess I could roll back motherboard bios until it works? This is all very annoying to get a $1500 gpu to work with hdmi...
 

lopoetve

Fully [H]
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Oct 11, 2001
Messages
32,692
yeah. I can’t remember if he tried hdmi or not, but having just seen that, it popped into my head.
 

Ej24

Gawd
Joined
Jun 11, 2016
Messages
628
Well here's a weird development. Everything works flawlessly if I enable CSM in bios and set all the devices to UEFI only. Pc boots up connected to TV via HDMI with CSM enabled. Disable CSM, try to boot connected to TV via HDMI and I get a BOOT led error on the motherboard.
 

lopoetve

Fully [H]
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Oct 11, 2001
Messages
32,692
Sounds like it's trying to boot in legacy BIOS mode- it doesn't have a VGA Option ROM, so that won't work anymore. Gotta be UEFI.
 

Ej24

Gawd
Joined
Jun 11, 2016
Messages
628
Sounds like it's trying to boot in legacy BIOS mode- it doesn't have a VGA Option ROM, so that won't work anymore. Gotta be UEFI.
My system is UEFI boot. Doubled checked in windows system information.

It boots perfectly if connected via DP or via HDMI to a standard pc monitor (regardless of CSM, secure boot, whatever, doesn't matter). What sorcery is this that it shits the bed when connected via HDMI to the LG TV though? The only way to get it to successfully boot when connected to the LG TV is with CSM enabled and everything set to UEFI. Or with a DP adapter, but that's causing issues with scaling and audio.

Reading various forums some people report similar-ish issues with Asus motherboards and potential fixes include Changing PCIE x16 to gen 3. Didn't work. Also some report moving the pcie ssd to a PCH m.2 slot rather than CPU. Haven't tried that yet.

Trying to boot with pcie gen 3 (everything else in bios set to default) it didn't POST at all with hdmi connection to TV. Upon hard reset I got post error saying it is booting to BIOS in safe boot mode (AMI splash screen, not windows). But booting with gen 3 works flawlessly with DP adapter to hdmi to TV. No post error.

This all seems to revolve around the hdmi connection to the TV. Even tried daisy chaining throughthe AV receiver, same behavior. Hdmi-CEC issue maybe?
 

Ej24

Gawd
Joined
Jun 11, 2016
Messages
628
How current is the firmware on the TV?
As up to date as is available from LG.
I disabled hdmi-cec and it made no difference.

Rolled back Asus motherboard BIOS through every version. Still won't boot when connected directly via HDMI. Gets stuck on BOOT led.

Moved sn850 ssd to a chipset m.2 slot, made no difference.

This really seems like a motherboard issue seeing as it will behave just fine with CSM enabled and set to UEFI, and when it fails to boot its entirely pre-OS so it's got to be firmware on either the motherboard or GPU. And CSM is not a viable long term solution if I ever want to move to windows 11.

Going to order a different brand of z690 motherboard as a sanity check. Going with MSI z690 Edge wifi. Too bad my Asus Tuf z690 is beyond the return window. Shame because I liked the Asus bios from a UI perspective.
 
Last edited:

Digital Viper-X-

[H]F Junkie
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Dec 9, 2000
Messages
14,811
Yup tried it already. Firmware is up to date according to nvidia tool.
That is specifically related to Displayport blank screen.
This is HDMI and not just blank screen but literally not POSTing
Ahh gotcha. Then I have no idea :( GL!
 

Brackle

Old Timer
Joined
Jun 19, 2003
Messages
8,071
Might be a stupid question. Did you try a HDMI 2.1 cord? I know the TV is 2.0 only but maybe the video card likes the 2.1 cord over a 2.0 cord?

I am grasping at straws....
 

Elios

Supreme [H]ardness
Joined
Aug 12, 2004
Messages
7,284
So is using CSM a problem? Does it impact performance or anything?
you ideally want it off. booting will be faster and windows needs it off for UEFI mode and its needed for reiszeble BAR
 
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