E223 displays only detect input signal when using a dedicated (desktop) graphics card

[Boulliebeest]

Hello everyone

I have bumped upon a strange issue, which - to me - completely defies all logic.

At our company, we have a mix of HP laptops, desktops and docking stations (elitebooks/zbooks) spanning several generations.

(except for a few leftover Surface tablets, our printers and a handful of screens, we're an All-HP-house) 

What we encountered twice already, is a strange issue occuring with E223 screens.

Both occassion happend in a similar fashion:

1.) The user's old laptop and docking station got replaced
2.) Everything works fine for a while (first occasion: >1 year, second 2 months)

3.) WIthout any clear indication of cause, the screen won't recognize the input anymore ("no signal detected", on HDMI, VGA and DP)

4.) Switching inputs --> No difference

5.) Power cycling screen, laptop, docking station (Thunderbolt dock G2, 230W with combo-cable) --> No difference

6.) Connecting the screen to the HDMI-port of the elitebook directly, or HDMI/miniDP port of Zbook (which has an Nvidia Quadro T2000 GPU) --> No difference

7.) Replacing/reseating all cables --> No difference

8.) Other/new screens --> No issue

At this stage, my best guess would be a faulty system board of the display.

However...

When you connect said "faulty" display to a desktop with a dedicated graphics card (as a test, I tried this on my personal PC's with a GTX 980 and 1080 TI), they work without any issue...
Signal is instantly detected, and picture is shown on the display.

Does anyone have an idea what might be causing this strange behaviour?

Thanks for your input!

[itsmyname]

@Boulliebeest -- 

Can you do some testing:

Result	Computer 1	Computer 2
Monitor 1	OK? No video?	OK? No video?
Monitor 2	OK? No video?	OK? No video?

where “Computer 1” is an ordinary desktop computer, directly connected to a display,

and “Computer 2” is one of your HP laptops, directly-connected to “Monitor 1”,

and “Monitor 2” is connected to a docking station that is connected to one of your HP laptops.

What results do you get?

[Boulliebeest]

@itsmyname , thank you for your feedback.

Both screens showing this behavior work fine, when connected to a desktop, on any of the inputs.

Neither of them work when connected to a laptop with/without docking station, on any of the inputs (tested on Dragonfly, EliteBook 850 G8 and latest gen Zbook Fury).

The laptop recognizes the screen (it shows up in display settings), but the screen keeps indicating 'no signal input'.  (I made sure the display was set to either duplicate or extend, and not disabled by any chance).

Using other displays on said laptops don't give any issues, they all work fine.

Extra info that might be useful:

All drivers/bios have been updated too (using HPIA), running W10 PRO 21H2, all updates installed.

[itsmyname]

@Boulliebeest -- but the screen keeps indicating 'no signal input'. 

Does your screen have multiple video-input ports (HDMI #1, HDMI #2, VGA, DVI, S-Video, coaxial, composite, or component) ?

You need to tell the screen which of those inputs is to be the "active" input, based on the connector on the video-cable that is connected to the back of the screen. Cycle through the choices -- one of them should eliminate that "no signal" message.

[Boulliebeest]

@Itsmyname actually, no, I don't need to set inputs.

The screen will automatically switch to the correct input when it receives signal.

Also, 'no signal' is shown next to all inputs in a nice overview.

HDMI: No input

VGA: No input

DP: No input

When cycling through the inputs manually (forcing the screen to go to a specific input), this doesn't solve anything.

[itsmyname]

@Boulliebeest -- The screen will automatically switch to the correct input when it receives signal.

I did not expect that. My monitor has multiple video-input connections, and it would be annoying to me if it "automatically" switched inputs.

How many video-output connectors do you have on your computer? VGA? DVI? HDMI? DisplayPort? S-Video?  Do you have more than one of each type of connectors?

What are the connectors on the video-cable between your computer and your monitor?

Have you tried using a different cable?

[Boulliebeest]

On the EliteBook we have HDMI only.

The Zbooks have 1 HDMI and 1 MiniDP.

The docking stations have 2x DP, 1x VGA.

The screens have 1x VGA , 1x HDMI, 1 x DP.

Cables tried:

VGA

HDMI

DP

MiniDP -> DP

No change when using these cables with the laptops.

Same cables at a desktop with dedicated graphics (Ports: 3x DP, 1x HDMI) -> no problem, screen works as expected.

[itsmyname]

@Boulliebeest -- so, is the following table correct, if you test each "Yes?", to change it to either "yes" or "no"

--------

Computer vs. screen	VGA	HDMI	DP
Elitebook - HDMI	X	Yes?	X
Zbook – HDMI	X	Yes?	X
Zbook – Mini-DP	X	X	Yes?
Docking station – DP	X	X	Yes?
Docking station – VGA	Yes?	X	X
Desktop – DP	X	X	Yes?
Desktop – HDMI	X	Yes?	X

???

[Boulliebeest]

Have copied your table, and marked the tests that failed to provide picture on the E223 displays in red, and the ones that worked in green.

Note that when using different displays (tested with E24 G4), all tests were succesful.

[itsmyname]

@Boulliebeest -- do you have (or can you borrow) a completely-different screen with either HDMI or DisplayPort input, to repeat those "red" tests?  Remember to tell the screen to try "listening" to each of its available video-input sources.

During each test, on each of the computers, hold-down the "Windows" key on the keyboard, and tap the "P" key, to see whether Windows detects more than one graphics-adapter.