User avatar
riffraff
Posts: 307
Joined: Tue Sep 27, 2011 3:17 am
Location: Newnan, Georgia, US

No Display in HDMI mode when booting Debian

Mon Feb 04, 2013 11:38 pm

This one has left me scratching my head.

When I got my Pi and booted it the first time with Debian, I noticed there was no display. My TV (a Philips 20" - 1080p is native mode) was showing it was in HDMI2 mode, but no boot stuff.

OK, I figured the display didn't initialize, maybe the TV didn't finish POST before the Pi, so I unplugged the power at the Pi board, plugged it back in and rebooted. Display goes to 1080p just fine. It's just aggravating to plug in the Pi after everything else is powered up just to get the display to initialize.

When I set up a Puppy Linux SD, I noticed it boots perfectly into1080p without intervention. Hmmm? What's the difference? In config.txt there's a notation about using hdmi_force_hotplug=1 with the comment: i have this problem if any usb device plugged in at startup.

I put this in the Debian config, and it successfully initializes the display in 720p mode. GUI then comes up in 720p as well. A quick reboot and the display comes up in 1080p mode, GUI as well.

Get this: No changes to hdmi_group or hdmi_mode in the config will fix this with Debian. Both distro SD's have identical bootcode.bin files. This is not an "X" issue because this occurs with the text at boot. No matter what I do, the only way to get the Debian distro to come up in 1080p is to reboot it.

So... does anyone have and ideas as to what the fundamental difference is between Puppy and Debian here? Can I fix this in Debian? Or do I just have a crappy TV.

It's really not that much of an annoyance to me, but I have others in the family who aren't that savvy who'll be using this particular unit.

Angerissues
Posts: 6
Joined: Fri Feb 01, 2013 9:58 am
Location: Perth, Western Australia

Re: No Display in HDMI mode when booting Debian

Tue Feb 05, 2013 2:44 am

Maybe try upping the HDMI signal strength.

It sounds more like the TV is struggling to get a good clean signal from the Pi. May be worth a shot.

May also be that Debian is struggling to read the edid (correct term?) from the TV, I know Raspbian on my pi doesn't. example - my pc screen runs native (1080p) on the pi, yet my tv which is 720 native only runs at 480 on the pi. I am personally having trouble getting the Pi to force a resolution, it's either what it reads from the screen or VGA).

If I sound like a total retard from the above, you're probably not that far off the mark ;)

Chris.
Raspberry Pi B Rev. 2
Raspbian OS

Please be patient with me, I am only learning. If I say something stupid, it's probably because I do not understand what you are trying to tell me.

Return to “Troubleshooting”