u/alberto5dlg

r/SamsungSupport Query

Query Identification: 01098172

Title: Samsung Odyssey OLED G9 G95SD – Random Signal Loss, Flickering, Artifacts & Phantom HDMI/DP Detection

Description:
I am experiencing serious intermittent signal and image stability issues with my Samsung Odyssey OLED G9 G95SD. The monitor randomly loses signal, flickers, shows black screens, green/pink artifacts and corrupted image blocks. Sometimes it displays “No Signal” on boot even when the PC is running correctly.

The strangest issue is that the monitor sometimes detects HDMI1, HDMI2 and DisplayPort as connected even when NO cables are connected to the monitor at all.

About a month ago I experienced the same issue and temporarily fixed it after multiple factory resets and hard resets, leaving only my main PC connected through DisplayPort. The monitor then worked perfectly for several weeks.

However, a few days ago I connected a second computer through HDMI for work while keeping my main gaming PC connected through DisplayPort, and after about a week all the issues returned again.

Things I have tried:
- Replacing all cables (including a new VESA-certified DisplayPort 2.1 cable)
- Different GPU DP ports
- HDMI instead of DisplayPort
- Hard reset and factory reset
- Disconnecting all cables
- Using only one PC connected
- HDR ON/OFF
- G-Sync ON/OFF
- Testing at 120Hz and 240Hz
- Proper power-on sequence (monitor first, then PC)
- Leaving the monitor unplugged overnight

Device Name: Samsung Odyssey OLED G9 G95SD

Device Model Number: LS49DG954SUXEN

Hi everyone,

I’m having a very strange issue with my Samsung Odyssey OLED G9 G95SD (49” DQHD 240Hz) and I’m trying to figure out whether this is a firmware issue, DSC instability, handshake problem, or an actual hardware fault.

My setup:
- Samsung Odyssey OLED G9 G95SD
- RTX 5080
- Ryzen 9800X3D
- Brand new Cable Matters VESA-certified DisplayPort 2.1 cable (80Gbps)

IMPORTANT:
This already happened to me about a month ago. At that time, after several factory resets and hard resets, I managed to get everything working normally again by leaving only my main PC connected through DisplayPort. After that, the monitor worked perfectly for weeks without a single issue.

However, a few days ago I connected a second computer through HDMI for work purposes while keeping my main gaming PC connected through DisplayPort, and after about a week all the problems came back again.

Symptoms:
- Random signal loss
- Screen flickering / black screen that comes back
- Green and pink artifacts
- Corrupted image blocks/tiles
- Sometimes “No Signal” on boot
- The monitor occasionally detects HDMI1 / HDMI2 / DisplayPort even when NO cables are connected
- Sometimes it works perfectly for 6+ hours at 5120x1440 240Hz HDR + G-Sync
- Other times it starts flickering after 10–15 minutes even while just watching Twitch or sitting on the desktop
- Unplugging the monitor from power for a few minutes sometimes temporarily fixes it

Things I already tried:
- New certified DP 2.1 cable
- Different GPU DP ports
- HDMI instead of DisplayPort
- Hard reset / factory reset
- Disconnecting all cables
- Using only one PC
- HDR ON/OFF
- G-Sync ON/OFF
- Testing at both 120Hz and 240Hz
- Proper power-on sequence (monitor first, then PC)

Important detail:
After leaving the monitor unplugged overnight, it still sometimes detects HDMI/DP inputs even with no cables connected at all.

This makes me suspect:
- DSC instability
- Firmware corruption/bug
- Handshake issue
- Input controller/main board issue

Has anyone experienced something similar with the OLED G9/G95SD?

Especially:
- phantom input detection
- random flickering + artifacts
- “No Signal” over DisplayPort
- instability after using multiple inputs simultaneously (HDMI + DP)

I’m trying to determine whether this is:
- a known Samsung firmware issue
- a DSC/VRR/HDR limitation
- or an actual hardware problem requiring RMA/warranty replacement.

Thanks!