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Can't get HDMI output - SOLVED

D

Dougb256

Newbie
I have an S21 5G and I'm trying to connect it to an external monitor. I have tried a USB-C to HDMI cable with no luck on two monitors. I looked at quite a few YT videos that said to use a USB-C to HDMI adapter with an HDMI cable. Those just arrived with the same results, no signal detected. At this point it either has to be a setting on the phone, or some simple user error. I can't find any HDMI settings for the S21. I am on Android 12. Some folks say go to Settings -> Connections -> More Connections -> HDMI, but my phone does not list the HDMI option. All I see are "Nearby device scanning", "Printing", "VPN", "Private DNS" and "Network unlock".

What am I missing?
 
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ocnbrze said:
why not just use samung dex? if you have a pc, you can connect your phone to the pc and then you can pretty mirror whatever you want from your pc.
https://www.xda-developers.com/galaxy-s21-wireless-support-samsung-dex-on-pc/
https://insights.samsung.com/2022/08/12/the-beginners-guide-to-samsung-dex-11/#using-dex-wirelessly

and if you decide against dex......it might be the cables being used. is it a high quality one? or some cheap chinese one?
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My wife uses her S21 for recording her YT videos, but she has to "wing it" and hope that she's sitting in the right place when recording. I want to hook up a little monitor on a tripod for her so she can see herself and get positioned correctly. I have followed the various instructions and cannot get it to work, nor do I have HDMI options in any of my menus. I have tried numerous cables and 2 different monitors.
 
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Madd63 said:
Is it a real S21?

https://play.google.com/store/apps/details?id=com.cpuid.cpu_z


https://androidyii.com/how-to-connect-a-galaxy-s21-to-a-tv-with-an-hdmi-cable/

BTW : I didn't know you could connect a smartphone with a simple non powered adapter, unlike a Chromecast for example. I guess it's only possible on flagship level devices whose port supports this.
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The article you posted is one that I read earlier. It says this:

"If the screen does not display on the TV, go to Settings–> Connections–> More Connection Settings–> HDMI Mode."

My S21 does not have an "HDMI Mode" option. I was thinking that maybe T Mobile blocks the HDMI output, but I went to their site and they have instructions on how to do it, so it doesn't appear that they block it. I am totally stumped.
 
Dougb256 said:
Third party unit, this one from Amaz*n:
USB C to HDMI Adapter, JSAUX 4K USB Type-C to HDMI Female Adapter [Thunderbolt 3 Compatible] for Samsung Galaxy S21 S20 Ultra Note 20 10 9 8 S10 S9 S8 Plus, Dell XPS 15-Grey
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Thunderbolt ? I always thought that was an Apple thing, with Macs, iPads, and iPhones? I've actually got a Samsung Galaxy Note20 Ultra myself, and I've never seen any mention of Thunderbolt with it.

Despite the description, are we sure that Samsung devices actually support this?
 
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mikedt said:

Thunderbolt ? I always thought that was an Apple thing, with Macs, iPads, and iPhones? I've actually got a Samsung Galaxy Note20 Ultra myself, and I've never seen any mention of Thunderbolt with it.

Despite the description, are we sure that Samsung devices actually support this?
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It's just a USB-C to HDMI converter. It has a USB-C cable attached on on end and an HDMI port on the other.

I also tried a USB-C to HDMI cable, same results. There shouldn't be anything proprietary needed.
 
It has to be a USB - C port with 3.1 / 3.2 certification for video output, most lesser devices use USB C 2.0 which have 5 to 10 times slower transfer speeds than the 5 - 10 Gbps of USB C 3.1 now called 3.2.

Many flagship devices from other manufacturers still only support USB - C 2.0. (a pet hate of a reviewer I like)

The Galaxy S21 has that 3.2 certification in it's spec sheet, for a genuine model.
If you got it directly from T-Mobile then it's unlikely to be a knock - off.

*There are Phone Spec / Device info apps like CPU - Z I linked above, however I couldn't find one that lists the USB C port specs.
 
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Madd63 said:
It has to be a USB - C port with 3.1 / 3.2 certification for video output, most lesser devices use USB C 2.0 which have 5 to 10 times slower transfer speeds than the 5 - 10 Gbps of USB C 3.1 now called 3.2.

Many flagship devices from other manufacturers still only support USB - C 2.0. (a pet hate of a reviewer I like)

The Galaxy S21 has that 3.2 certification in it's spec sheet, for a genuine model.
If you got it directly from T-Mobile then it's unlikely to be a knock - off.

*There are Phone Spec / Device info apps like CPU - Z I linked above, however I couldn't find one that lists the USB C port specs.
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Just for the heck of it I ran CPU Z. It says that it's a Samsung SM-G991U, so it's no knock-off. Yes, purchased directly from T Mobile.
 
That is odd. I would try another adapter, (I haven't re - read your posts) , and then get on to Samsung or one of their stores if you have one near.

Also, if Im allowed, I would try Sammobile to see if there are similar reports.
 
Samsung Tech Support is lost too and are reaching out to get more info. It's practically impossible for them to NOT try to get me to connect wirelessly; I've told them repeatedly that it's HDMI connection only to these monitors, there is no wireless option. Apparently we don't use cables to connect things anymore.
 
The problem has been corrected! I went to the repair shop and they had it working in 5 minutes. The issue? My USB port was dirty, so it couldn't make a connection. I tried it when I got home and it works perfectly. It auto-starts DEX, so I had to go into my Notification bar and turn DEX off; then it mirrors what is on your screen. I rarely use my USB port and I charge it with one of those chargers that you lay the phone on, so I didn't know that the USB port was getting dirty.
 
Dougb256 said:
The problem has been corrected! I went to the repair shop and they had it working in 5 minutes. The issue? My USB port was dirty, so it couldn't make a connection. I tried it when I got home and it works perfectly. It auto-starts DEX, so I had to go into my Notification bar and turn DEX off; then it mirrors what is on your screen. I rarely use my USB port and I charge it with one of those chargers that you lay the phone on, so I didn't know that the USB port was getting dirty.
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glad they figured it out......such a simple solution:thumbsupdroid:
 
@Dougb256

Cool!

Thanks for letting us know.

You can buy coloured plastic plugs for usb port and headphone jacks very cheaply.

I guess many people never use the port at home or work, so that's worth remembering here.

Some ports can warp over time as well, depending on the material quality.

Definitely solved. :thinking: :)
 
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