Pi will not boot up on monitor

[psuteam]

Hi, I've been unable to use the video or still image pi as a computer. After following all instructions, the red and green lights come on but the monitor screen shows absolutely no indication of being connected to the pi. Do we need to load some graphic interface software onto our pis?
Thank you!

[Skylar MSGC]

No the image that you put on the SD card should have the nessesary hardware to start up a interface. You should be able to see a terminal like enviorment.

The red light should be solid the whole time while the green light should be flashing on and off and non-symmetric patterns. If the green light is solid, your card isn't all the way in or it is corrupted.

[Wesley]

Does the pi still boot normally and take pictures or take video?

[psuteam]

When I attempt to use the pi as a computer, the red light is solid and the green light blinks erratically just like they're suppose to. I've tried both video and still pis, 2 different monitors and 2 different HDMI cables. I can't get any response on the screen.

Both pis boot up normally. The video records just fine but I'm having some issues with the still image (most likely unrelated.)

Any further suggestions would be VERY appreciated!

[Wesley]

Can you ssh into a pi and type the command "sudo nano /boot/config.txt" and look for lines containing HDMI?

[psuteam]

This is what I got. Its all a bit vague and I'm not sure what "uncomment" means. If you could clarify what I should be looking at, that would be very helpful!

# For more options and information see
# rpf.io/configtxtreadme
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

# uncomment if hdmi display is not detected and composite is being output
#hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=1
#hdmi_mode=1

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
#hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL

[irowe]

The "#" signs in front of each line means that it is a comment, not a actual line of code. These lines are for the benefit of humans who read the code and are not run by the computer.

However, if you delete the leading pound sign, the line of code will be run by the computer. For example, in the second to last paragraph, there is a line that says "Uncomment to increase signal to HDMI". That means that if you were to delete the pound signs in front of the following two lines of code in that paragraph (not including the instructions themselves), the signal to the HDMI would be increased.

Perhaps trying that first suggestion, enabling the safe mode, might work.

[psuteam]

Thanks for explaining. I uncommented the following lines but this seems to have had no effect:

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

# uncomment if hdmi display is not detected and composite is being output
#hdmi_force_hotplug=1

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4


Any other ideas?? Thank you!

[psuteam]

I finally got it to work - I had to press a button on the monitor to select HDMI mode!

[Wesley]

To confirm, your config file now looks exactly like this? (No '#' in front)

# uncomment if you get no picture on HDMI for a default "safe" mode
hdmi_safe=1

# uncomment if hdmi display is not detected and composite is being output
hdmi_force_hotplug=1

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
config_hdmi_boost=4

[Skylar MSGC]

To be clear, there should be no reason to edit config files on the pi just to get it to work on the monitor.  This has not been disabled since that would make testing of new changes difficult and when there is no monitor hooked up to the HDMI port it won't use waste memory trying to render when there is no output.

Make sure to double check your Wiring, monitor plugs, look for any bent/missing pins on your cables.  Since most of the groups are new to the Raspberry Pis make sure to take your time in diagnosing your setup.

[Wesley]

Skylar is right. Most teams should not have a problem with displaying to the monitor as it is not disabled. Your team is experiencing a different issue. I would strongly recommend debugging after the eclipse to prevent creating a larger problem that will prevent your payloads from operating correctly.
For future reference, the most common problem I've encountered related to no output to monitors is a weak signal. Fixes for this may be as simple as checking for cable damage like Skylar mentioned and ensuring that you have a higher quality HDMI cable. If all else fails, the boost setting is one of a few settings that may help. For now, if your Pis are doing their job and you can stream from them, hold off on modifying anything on the Pis until after the eclipse. We'll still be here to help you debug after the eclipse.

[psuteam]

I posted a few days ago that I had fixed the problem by pressing a button on the monitor to switch it into HDMI mode. So no worries!! Thank you!