Stop stealing HDMI!
June 5, 2020 8:09 AM Subscribe
I'm trying to run two monitors off my laptop, and I'm having a very specific problem.
My desired home office setup is:
- two monitors
- closed Thinkpad laptop (I want to never use the laptop screen as a monitor while at home)
- ability to detach laptop easily to be mobile (I have to go to my office 1-2x/week)
My laptop has the following ports:
- 1x HDMI
- 2x USB-A
- 1x USB-C
It was recommended that I buy this hub in order to make the two monitor setup work, so I did. I find that when I plug an HDMI cable into the port on the hub, it overrides/steals/shuts down the HDMI port on the laptop itself. I don't know how to "fix" that.
Is there a Windows setting somewhere that will allow both HDMI ports available? The laptop's running Windows 10, and I don't have admin rights to it, so I can't do any serious mucking around. I'm not averse to buying a more powerful dock if necessary, but I'd rather make this one work if possible.
My desired home office setup is:
- two monitors
- closed Thinkpad laptop (I want to never use the laptop screen as a monitor while at home)
- ability to detach laptop easily to be mobile (I have to go to my office 1-2x/week)
My laptop has the following ports:
- 1x HDMI
- 2x USB-A
- 1x USB-C
It was recommended that I buy this hub in order to make the two monitor setup work, so I did. I find that when I plug an HDMI cable into the port on the hub, it overrides/steals/shuts down the HDMI port on the laptop itself. I don't know how to "fix" that.
Is there a Windows setting somewhere that will allow both HDMI ports available? The laptop's running Windows 10, and I don't have admin rights to it, so I can't do any serious mucking around. I'm not averse to buying a more powerful dock if necessary, but I'd rather make this one work if possible.
Best answer: Once you plug into your dock and then go to the display settings do you see to displays or just a single display? I suspect you may need to install display drivers for your dock and possibly update display drivers for your onboard graphics chip set. This will be problematic without admin rights.
posted by jmsta at 8:16 AM on June 5, 2020
posted by jmsta at 8:16 AM on June 5, 2020
Response by poster: Only a single display - whichever one is plugged into the hub I bought, not the laptop itself, wins. Both monitors work fine, as I tested when I discovered the source problem; the hub is stepping on the onboard HDMI and causing only one monitor to display at a time. "Detect displays" says "cannot detect additional displays".
posted by pdb at 8:20 AM on June 5, 2020
posted by pdb at 8:20 AM on June 5, 2020
What model of Thinkpad do you have? (And what GPU, if you can find that info?)
posted by mbrubeck at 8:24 AM on June 5, 2020
posted by mbrubeck at 8:24 AM on June 5, 2020
I've found that there's a considerable difference between hubs that use the USB-C power and ones that are separately powered. So rather than using a USB powered hub for my two external monitors, I use this hub. It's a bit pricier than the one you're using, but it offers real multi-monitor output with an external power supply.
Not a direct answer, but it might end up being the solution you need in the long run.
posted by wile e at 8:37 AM on June 5, 2020 [1 favorite]
Not a direct answer, but it might end up being the solution you need in the long run.
posted by wile e at 8:37 AM on June 5, 2020 [1 favorite]
Response by poster: @mbrubeck it says it's a T490S/Intel i7, but I'm not sure whether this is an older version or just differently spec'd, because it doesn't have a second USB3 as the specs here show.
@wile e - yeah, that's the fallback plan if I can't get this to work.
posted by pdb at 8:43 AM on June 5, 2020
@wile e - yeah, that's the fallback plan if I can't get this to work.
posted by pdb at 8:43 AM on June 5, 2020
On the t480 machines we have here at the office, there are two USB-C ports, and a BIOS setting which determines which can be used independently of the HDMI port.
The specs you link to seem to list one of the USB-C ports as PD only, but a similar configuration is on the t480 model.
Perhaps look through the BIOS settings and see if there is a USB-C Front/Back setting? Or just try the other USB-C port to see if it turns off the HDMI?
All of this is complicated by USB-C being a connector, and it's the protocols and graphics card that really define what's supported.
posted by tomierna at 8:52 AM on June 5, 2020
The specs you link to seem to list one of the USB-C ports as PD only, but a similar configuration is on the t480 model.
Perhaps look through the BIOS settings and see if there is a USB-C Front/Back setting? Or just try the other USB-C port to see if it turns off the HDMI?
All of this is complicated by USB-C being a connector, and it's the protocols and graphics card that really define what's supported.
posted by tomierna at 8:52 AM on June 5, 2020
Thinkpads have a type code on the bottom, next to the serial number: four digits, dash, three letters or digits (9413-FEG as an example). With that code you can look up the exact specs.
posted by Stoneshop at 8:57 AM on June 5, 2020
posted by Stoneshop at 8:57 AM on June 5, 2020
Is the laptop screen staying active during this? It may be that your system isn't capable of driving three monitors and it's assuming that you want the on-board screen to stay available (even if you have it physically closed). There's a setting in the displays control that changes this - it doesn't require admin access.
posted by Candleman at 9:36 AM on June 5, 2020
posted by Candleman at 9:36 AM on June 5, 2020
Response by poster: after an agonizing amount of time on the phone with our help desk, updating drivers solved the problem. Thanks all!
posted by pdb at 9:55 AM on June 5, 2020 [3 favorites]
posted by pdb at 9:55 AM on June 5, 2020 [3 favorites]
Additionally, DVI has two modes: DVI-I and DVI-D. DVI-D uses the same digital signalling as HDMI so you can buy a dongle to put in the back of the monitor to accept HDMI cables.
posted by k3ninho at 1:57 AM on June 7, 2020
posted by k3ninho at 1:57 AM on June 7, 2020
This thread is closed to new comments.
posted by pdb at 8:10 AM on June 5, 2020