Unsolved
1 Rookie
•
3 Posts
0
33
P2424HEB MST dock, second P2422H, occasionally 2nd monitor stops working
Hello,
I've got a weird issue and I'm hoping to get some ideas on how to troubleshoot it. Apologies if this has been mentioned before, searche but didn't see a reference to this particular model
Dell Latitude 7440 - Windows 11 Pro 22H2 (Build 22631.3447)
Dell P2424HEB - Firmware 0.0.37
Dell P2422H
TL;DR - the 2nd monitor, plugged into the dock of P2424HEB, will occasionally not wake up with the system. Computer doesn't recognize the 2nd monitor. The only solution is to pull power off 2nd monitor and wait 10 to 20 seconds, then plug back in.
The dell latitude is plugged into the P2424HEB via the provided USB-C cable and the P2422H is plugged into the P2424HEB via a DisplayPort cable.
The P2424HEB works as the primary monitor and the P2422H is in extended desktop as the secondary.
Issue: The 2nd monitor will stop working. It claims that the cable isn't plugged in (even though it is) and the system acts like a 2nd monitor isn't plugged in.
Conditions: this usually happens after a system is plugged into the USB-C cable and the system wakes up. It also happens after the system goes to sleep (but isn't unplugged from the dock) and then you return to the system and wake it back up. There is no rhyme or reason to the timing of the issue appearing. The only way to get the monitor back is to unplug the power from the 2nd monitor and wait a few seconds, then plug it back in. Nothing else can get that connection to return.
It's also worth noting that my system is not the only system experiencing it. I have mutliple P2424HEB/P2422H combos in my system and they all seem to be having this problem, with no obvious clause. The laptop model involved by may be different but it's always a current dell laptop
Solutions attempted: New DisplayPort cable from P2424HEB to P2422H. New power scheme settings on Windows 11. Confirm all drivers are up to date. Confirm windows is up to date. Updated firmware on P2424HEB. Confirm BIOS is at the latest.
Again, none of the above solutions fix it. I've tried digging into Event Viewer logs but can't find anything obvious.
Would love to get some feedback here on other troubleshooting steps or solutions I could try.
DELL-Chris M
Community Manager
Community Manager
•
54.2K Posts
0
April 18th, 2024 11:30
In all of your testing, is the Laptop on battery only? If yes, plug the provided AC power adapter into the Laptop and retest.
In all of your testing, is the Laptop lid closed? If not, try this.
See page 56 = Connecting the monitor for USB-C Multi-Stream Transport (MST) function in DPBS mode
jb-eff
1 Rookie
1 Rookie
•
3 Posts
0
April 18th, 2024 15:18
@DELL-Chris M thanks for the reply!
In these cases, the laptop power is being provided when we plug the USB-C cable from the 2424heb into the laptop.
Speaking for myself, my lid on my laptop is always closed before plugging it into the dock. I prefer doing that instead of plugging in the laptop, then closing the lid. Default settings for windows would cause it to go back to sleep at that point.
Thanks for the point to page 56, that might shed a little light on the situation, where the P2422H hooked into the 2424HEB may not be receiving the signal to 'wake up' after I plug the cable into the laptop. In most cases, we never turn our monitors off, they always stay in standby mode unless active. I'm going to try out the monitor settings regarding sync/power savings and report back.
DELL-Chris M
Community Manager
Community Manager
•
54.2K Posts
0
April 19th, 2024 11:12
"In all of your testing, is the Laptop on battery only? If yes, plug the provided AC power adapter into the Laptop and retest."
My point was when on battery only, the operating system will limit performance to save battery life. Which might be the cause of the issue. So remove that from the troubleshooting equation by connecting the Laptop AC power adapter to the Laptop.
jb-eff
1 Rookie
1 Rookie
•
3 Posts
0
April 23rd, 2024 17:44
Update:
1. Attempted to use some of hte internal monitor settings to see if it would fix the problem. Namely Display -> Multi-Monitor Sync (kept on) and Dell Power Button Sync set to Off. That did not work
2. reversed the settings for MM Sync to Off and DPBS to On. That also did not work
3. I plugged in the laptop to a separate power source, and the issue still happens. It took me a few days of trying each setting because it's not consistent when it does happen.
Thanks in advance for any other ideas