Raspberry Pi 4 turn on/off HDMI Ports

[mohyddin]

I am running Buster on RPI 4 connected to a 7" LCD screen and a projector, but I haven't succeeded yet in figuring out how to turn off a specific HDMI port and not both. I tried

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tvservice -o -v 7

and it worked but when I tried

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tvservice -p -v 7

I only got a blank screen.

On the other hand,

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vcgencmd display_power 0

worked but it turned both ports off at the same time.

does anyone know what I could do to get this working and whether it is possible to do so or not on the pi 4?

Ta

[trejan]

On the other hand,

Code: Select all

vcgencmd display_power 0

worked but it turned both ports off at the same time.

does anyone know what I could do to get this working and whether it is possible to do so or not on the pi 4?

They added support for individually turning on/off the HDMI PHYs in the development firmware on 1st November.

"vcgencmd display_power 0/1 display_id" where display_id is 2 for HDMI 0 and 7 for HDMI 1.

You need to wait for a new stable firmware release with those changes or use rpi-update to get the development firmware. The usual warnings about how it is development firmware etc...

[mohyddin]

Thanks a lot, this sounds great, I think I'll wait for a stable release. Btw, do you know what should I look for to solve the blank screen I'm getting when using tvservice -p -v 7?

[6by9]

tvservice -o will remove all display elements from the output, and that includes the framebuffer.
Use something like "fbset -depth 16 && fbset -depth 32" to change the framebuffer properties and reinstate it on the display.

[mohyddin]

I have tried to run "fbset -depth 8 && fbset -depth 16" then xrefresh before, but I was getting an error that no set modes for that resoultion in fb.mode I have only configure my screen in config.txt according to the screen manifacturer. what should I add to fb.mode to get fbset command to work?
Also, should I use depth values 16 and 24 instead?

Ta

[Tom Austin]

I have a fresh new Pi 4 from CanaKit. HDMI 0 is physically damaged, but I need only one HDMI monitor if I can use HDMI 1. I'm considering not returning the PI if I can get HDMI 1 to work. So far I can't get HDMI 1 to work, so I enabled composite out, and that works fine, but of course not with a proper monitor. It proves it boots fine.

1. With normal boot, should HDMI 1 be working regardless of whether HDMI 0 is connected?

2. Does HDMI safe mode turn on both HDMI ports so you can boot with either one?

3. If HDMI 0 is turned off, does that force HDMI 1 to work?

4. Is this PI new enough to such that the firmware will support turning off the broken HDMI 0?

5. I don't know if the PI was defective or if the cable was, but the fit was not proper. Every cable I use wiggles and doesn't snap in. Is this normal for micro HDMI? Was it me that damaged the ports by pushing enough for it to snap in? I didn't push that hard. I just want to know what to expect.

Thanks for your help.

[aBUGSworstnightmare]

...
5. I don't know if the PI was defective or if the cable was, but the fit was not proper. Every cable I use wiggles and doesn't snap in. Is this normal for micro HDMI? Was it me that damaged the ports by pushing enough for it to snap in? I didn't push that hard. I just want to know what to expect.

what about letting us know which cable you're using (is it the official one) and how it looks like when plugged in to HDMI0 and HDMI1 (pictures please)?

Why do you want to keep it if it arrived damaged? Have it returned under warranty (o.k. Not possible in case you did the damage).

[Tom Austin]

...
5. I don't know if the PI was defective or if the cable was, but the fit was not proper. Every cable I use wiggles and doesn't snap in. Is this normal for micro HDMI? Was it me that damaged the ports by pushing enough for it to snap in? I didn't push that hard. I just want to know what to expect.

what about letting us know which cable you're using (is it the official one) and how it looks like when plugged in to HDMI0 and HDMI1 (pictures please)?

Why do you want to keep it if it arrived damaged? Have it returned under warranty (o.k. Not possible in case you did the damage).

I'm using the micro HDMI cable supplied by CanaKit. They graciously sent me another cable, since I couldn't tell whether the PI damaged the cable or vice versa. It doesn't fit HDMI 1 any better than the first one did, which is now damaged.

I don't know if the PI arrived damaged or whether I somehow damaged it. I can see a bent pin in HDMI 0, which I"m guessing happened when I plugged in the cable.

This is my fifth PI and I know how to use them, yet this is my first experience with micro HDMI. It wiggled and was not plugged in the slot all the way, leaving a gap about the width of a credit card. This is why I'm asking those with experience to describe how micro HDMI feels and acts when it gets plugged in. Should it be a clean fit, or should I expect it to stick out some and wiggle?

[jamesh]

...
5. I don't know if the PI was defective or if the cable was, but the fit was not proper. Every cable I use wiggles and doesn't snap in. Is this normal for micro HDMI? Was it me that damaged the ports by pushing enough for it to snap in? I didn't push that hard. I just want to know what to expect.

what about letting us know which cable you're using (is it the official one) and how it looks like when plugged in to HDMI0 and HDMI1 (pictures please)?

Why do you want to keep it if it arrived damaged? Have it returned under warranty (o.k. Not possible in case you did the damage).

I'm using the micro HDMI cable supplied by CanaKit. They graciously sent me another cable, since I couldn't tell whether the PI damaged the cable or vice versa. It doesn't fit HDMI 1 any better than the first one did, which is now damaged.

I don't know if the PI arrived damaged or whether I somehow damaged it. I can see a bent pin in HDMI 0, which I"m guessing happened when I plugged in the cable.

This is my fifth PI and I know how to use them, yet this is my first experience with micro HDMI. It wiggled and was not plugged in the slot all the way, leaving a gap about the width of a credit card. This is why I'm asking those with experience to describe how micro HDMI feels and acts when it gets plugged in. Should it be a clean fit, or should I expect it to stick out some and wiggle?

Should be firm, with a click click as it goes in. If its wiggling it's broken.

[Tom Austin]

Ok, then I'm returning it. I'm sure I didn't break both ports and both wiggle.

Meanwhile:


1. With normal boot, should HDMI 1 be working regardless of whether HDMI 0 is connected?

2. Does HDMI safe mode turn on both HDMI ports so you can boot with either one?

3. If HDMI 0 is turned off, does that force HDMI 1 to work?

4. Is this PI new enough to such that the firmware will support turning off the broken HDMI 0?

[ghochenauer]

I have the same problem. Both HDMI micro ports seem to have some extra metal pin on the upper left, causing damage to the cable when inserting it.

[jamesh]

I have the same problem. Both HDMI micro ports seem to have some extra metal pin on the upper left, causing damage to the cable when inserting it.

Have you got a picture of the problem? That would be useful.

EDIT: Actually, a picture has been requested by our HW guys, so VERY useful! See if you can get enough detail so we can see inside the plug.