XPS 15 9750, HDMI monitor goes to black

Hi after HDMI stopped working I got this

https://www.amazon.co.uk/gp/product/B08GF82TP4

Works flawlessly so far.

Daniel

I have been having the same issues. I used my Dell XPS 15  with an LG External Ultrawide Monitor (29UM58-P) at my office for over 2 years.  Never had an issue. It started flashing in and out and then went black all together sometime in mid Jan. It drove me crazy. I have tried everything. Different HDMI cables, I went through support with LG on the monitor, Brought another laptop in to show that the monitor does work as do both cables, then took my DELL XPS 15 home and it will work with the LG 4KMonitor at the house that I mostly use with my CPU. I am so frustrated. I have been through numerous tech support calls, deleted drivers, reinstalled drivers etc. Even ran the diagnostics.  No one can figure out what the problem is. I have ordered an HDMI to USB-C adapter and it will be here this week so I can give that a try. If anyone has any other hints, helps or suggestions I am wide open.  This is so frustrating and I have been giving way too much time to trying to solve it!  

Sorry to hear about your experiences. It's really a shame Dell puts users in that position.

I know this does not help, but from what I can tell, it sounds you did you investigation a little bit back-to-front. From my experience it's better to do a binary-chop approach (or divide-and-conquer) and make a decision when to stop.

For example:

Is it a monitor or a laptop? (use another monitor and/or laptop). Laptop.

Is it Windows or all OSes? (boot it with live-CD of Ubuntu etc.). All OSes (I'm guessing I did not try that).

All OSes means hw issue. If just Windows you may look at the drivers, check what has been updated etc.

Is it just HDMI or USB-C as well. Just HDMI.

Of course, it may be difficult if you don't have things at hand (extra monitor, cables etc.)

This puts you in the right place fairly quickly. Then you can contact Dell at this point without spending much time and energy. This is the only way to stay sane I think.

As I said I know it does not help but maybe it's something for the future.

As a consolation, I think you will be happier once you get your HDMI-USB-C adaptor.

Regards

Daniel

@ivenhov , If @SBELLESC 's issue is the same as mine (and the reason why I started this thread) it must have to do with the firmware. Last year I tried all that and more and reached that conclusion. About Dell, they don't care. I've tried to contact them many times by email, social media, etc. When I mention this issue, they just send me links with basic information about how to handle HDMI cables, which I find insulting. I'm not buying Dell again. It's unbelievable (and unforgivable) that they create such technical problems and don't solve them.

My current Dell XPS is only 2 years old and is very powerful, but I'll look for an alternative the next time I need to buy a laptop. It's only due to this issue. Other than that, I've loved the laptop. But I think it's very dangerous to buy products from people so careless and sloppy. I'm a neuroscientist - I was writing my PhD thesis at the time and needed two screens to work. I think I had never hated a company so much in my life before.

@SBELLESC I've used this adaptor. It worked like a charm. Let's hope Dell won't kill the USB-C function at some point: https://www.amazon.co.uk/Adapter-Thunderbolt-Compatible-MacBook-Pixelbook/dp/B07JW7GT7H/ 

I have exactly the same problem that surfaced recently, going on the theory that this is a BIOS introduced problem I have highlighted below the BIOS revisions for which this problem exists. 

Note: We are strictly discussing HDMI port (Laptop) directly connected to TV/Monitor that is having an issue. 

BIOS Release Observations

1.19.0  (May 2021)  - Problem Exists

1.181   (Jan 2021)  - Problem Exists

1.17.1 (Aug 2020)  - Not sure 

1.15.0  (Jan 2020)  - and below, No problem, everything worked perfectly

Hopefully the above can help Dell to understand pinpoint the changes in BIOS that impacted the HDMI port.  From my point of view even though a work around (using USB-C) exists its not acceptable that HDMI port is lost due to BIOS update. 

If this is not BIOS related issue, then apologies, nevertheless a solution is still needed for this problem.

 For sure it can not be that all of a sudden a number of XPS 15 9570 Laptops starting having the same problem. 

Thanks @eednig Unfortunately, the main issue here is that Dell doesn't care at all.

Exact same issue, but with a bit of extra sugar.

Current Setup:

• External monitor connected via HDMI on my 9570.
• USB-C LAN adapter connected to the USB-C/Thunderbolt port next to the HDMI port.
• Win 10 Pro 21H1
• BIOS 1.20.0
• Embedded controller 1.0.38
• Intel ME 12.0.81.1753
• Thunderbolt Controller 3 (15D9), NVM Firmware 46.00
• Thunderbolt Software 17.4.79.510
• Thunderbolt Controller Driver 17.4.79.11
• Intel Display Drivers 27.20.100.8935
• NVIDIA 471.68

All updates are installed according to "Dell Update" and Windows Update.

The setup was working like this since November 2018.

New problem:

Since roughly a week, the ext monitor sometimes turns black and back on, randomly. Sometimes quickly repeatedly in a row, sometimes not for hours.

If I disconnect the LAN adapter from the USB-C port, the external monitor turns black immediately, if I plug it back in, the monitor returns instantly. (The monitor is not really disconnected fully, as Windows keeps the monitor setup, where the external one is the main desktop. It just turns black.)

The fun part: It does not matter what I plug into the USB-C port. It is even sufficient to attach a "dumb" USB-C/USB-A adapter and the monitor is back on.

Effectively, I currently need something connected on the USB-C port in order to be able to use the HDMI port, even though it flickers sometimes.

Analysis:

Regarding the timeline, I suppose this must be related to updates released end of July/start of August:

• Thunderbolt: https://www.dell.com/support/home/de-at/drivers/driversdetails?driverid=d86t2&oscode=wt64a&productcode=xps-15-9570-laptop
• BIOS: https://www.dell.com/support/home/de-at/drivers/driversdetails?driverid=0y84m&oscode=wt64a&productcode=xps-15-9570-laptop
• Intel Display Driver
• NVIDIA

Does anyone have an idea what the heck is going on all of a sudden?
Are the GPU drivers related at all or can they be ruled out in this case?

Thanks for any idea on how to proceed here. (warranty is obviously over, hence no support from Dell)

A few things I tried additionally:

• Downgrading the Intel driver to v27.x
• Resetting all monitor configuration within Windows via Registry
• Exchanging the HDMI cable

The monitor (an LG 24MB56) works flawlessly on another laptop.

Even stranger: Another monitor (LG 34UM88) works flawlessly on the XPS via HDMI! (no need to connect anything to USB-C)

A few things I tried additionally:

• Downgrading the Intel driver to v27.x
• Resetting all monitor configuration within Windows via Registry
• Exchanging the HDMI cable

The main monitor (an LG 24MB56) works flawlessly on another laptop.

Even stranger: Another monitor (LG 34UM88) works flawlessly on the XPS via HDMI! (no need to connect anything to USB-C)

Funky stuff: XPS with LG 24MB56 via HDMI, without USB-C device connected, works flawlessly using a live Linux (e.g. gparted)

My conclusion therefore: It must be some combination of a driver and this specific monitor that drives the mess. I strongly suspect the Thunderbolt driver now.

This problems Usually are caused by power. specially if you have been having it connected to charger constantly.

It can be the the charger, Power, or city's power grid.

In my trips to countries with higher voltages, I experienced much less problems.

There are 2 things that might help:

1- Try to slowly moving yor HDMI cable port that is connected to your laptop (very slow and not much at all). if your screen goes black, it can indicate that the HDMI portal is lose. this can cause the connection to be reset with natural vibrations around you.

Usually in hardware related problems, like lose ports, when monitor comes back, it shows connection details. as if you just connected the monitor again. this can also happen if system has power management or other hardware problem that cause the HDMI to get disabled completely.

2- Unfotunately, BIOS problems and Dell have a long history.

A solution that works for me, is turning the system up with HDMI and CHARGER disconnected. after system comes up and initial high power consuming processes are done, I connect HDMI and then the charger.

Make sure performance setting to be automatically set on "balanced" or lower when charger is not connected.

This helps because system manages power differently on different performance settings. when you are on "Best Performance" and have charger connected and turn the system on, initial processes are allowed to consume as much power as they want. I believe the low voltage, and the excuse of chargers that dell makes, cannot handle this properly, and in lack of proper Bios, this happens.

Usually when I do this I don't experience problems even after I connect the charger.

In general you wanna save on power.

I have exactly the same problem.

Run all the tests (changing the cable, check all the drivers, run diagnostic, etc), and nothing!

This is the most expensive laptop that I've ever had and is the less reliable.

Same issue here.  Happened after upgrading to BIOS v1.18.0.

I have got round the issue by connecting a USB-C docking station and connecting the HDMI cable to that.

I started having this problem after I updated BIOS to the latest version 1.27.0, now I am using the USB C thunderbolt port instead of HDMI but I would prefer DELL to address this firmware issue.

I have reverted my bios to the older version 1.26.0 and after that, the problem was solved. so it confirmed that the problem is with the latest bios version 1.27.0.

I have found that if you select an interlaced refresh rate it fixes the issue of the screen turning on and off intermittently. However it is not a perfect solution as my screen can only do interlaced at a low refresh rate.

I am running two dell monitors with my XPS 15 9750  one on the dedicated hdmi port and one on a usbc -> hdmi converter. only the one on the dedicated port has been giving issues as of late.