MoraPi
Posts: 19
Joined: Fri Aug 16, 2013 3:23 am

raspian won't boot

Sat Aug 24, 2013 4:10 pm

This is what can be found inside my config.txt file:

# 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
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# for more options see http://elinux.org/RPi_config.txt


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is there something missing there? is that the reason i can't seem to boot raspian after installing it, and instead all i get is a blank, unresponsive screen? Should i write somethign in or edit something out? I'm COMPLETELY new at coding, as in i don't know how to and i don't understand what it is i'm looking at in that config.txt file. Please help!

User avatar
rpdom
Posts: 14427
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: raspian won't boot

Sat Aug 24, 2013 4:17 pm

Start with the usual questions.

What does the Green ACT LED do when you power up? Flash once, stay dark, glow faintly, flash a number of times in a repeating pattern? That will tell if the Pi is booting up at all.

Assuming it is booting correctly (LED comes on for a second or so, goes out for a bit, flickers a lot for a few seconds), you probably have a video output issue and may need to change config.txt.

Troubleshooting details are at http://elinux.org/R-Pi_Troubleshooting

Probably the first thing to try, if you are using HDMI, is to remove the # from hdmi_safe=1 to boot in "works for anything HDMI" video mode. If that works, try changing some parameters as described in the troubleshooting guide until everything is right.

Please report back what happens :)

MoraPi
Posts: 19
Joined: Fri Aug 16, 2013 3:23 am

Re: raspian won't boot

Sat Aug 24, 2013 9:32 pm

rpdom wrote:Start with the usual questions.

What does the Green ACT LED do when you power up? Flash once, stay dark, glow faintly, flash a number of times in a repeating pattern? That will tell if the Pi is booting up at all.

Assuming it is booting correctly (LED comes on for a second or so, goes out for a bit, flickers a lot for a few seconds), you probably have a video output issue and may need to change config.txt.

Troubleshooting details are at http://elinux.org/R-Pi_Troubleshooting

Probably the first thing to try, if you are using HDMI, is to remove the # from hdmi_safe=1 to boot in "works for anything HDMI" video mode. If that works, try changing some parameters as described in the troubleshooting guide until everything is right.

Please report back what happens :)
based on your answer, it has to be a video output issue. for the first 30 seconds or so, the green light flickers on and off repeatedly. after that, it sometimes flickers if i press a key on the keyboard, however the tv screen remains "detecting" and doing nothing else. Sooooooooometimes it says "no signal" but then reverts to "detecting."

i'm going to try the link you provided and see what happens.

User avatar
DrPiD
Posts: 30
Joined: Wed May 16, 2012 9:44 am
Location: Leamington Spa, UK
Contact: Website

Re: raspian won't boot

Tue Aug 27, 2013 8:10 am

FYI, the problem was the HDMI Safe mode. Despite being part of the HDMI specification, it isn't supported by all devices, I've had issues with it on an LG Monitor and my Samsung TV at home.

If you experience similar issues, where the Pi looks to be booting ok but there's nothing on screen try this:

I find that adding the following to the file, you can just paste this straight into the config.txt file on your SD card.

Code: Select all

# Force the monitor to HDMI mode so that sound will be sent over HDMI cable
hdmi_drive=2
# Set monitor mode to DMT
hdmi_group=2
# Set monitor resolution to 1024x768 XGA 60Hz (HDMI_DMT_XGA_60)
hdmi_mode=16
If that doesn't work you can change the hdmi_mode=16 to another number. You can find the list of resolutions here. You want the second list where it lists them as 800 x 600 etc.
Community Manager - IndieCity

theArtist
Posts: 7
Joined: Tue Aug 27, 2013 9:02 am

Re: raspian won't boot

Tue Aug 27, 2013 9:22 am

Did you try uncommenting the first line of the *config.txt* file?

From

Code: Select all

#hdmi_safe=1
to (notice the missing # character in the line)

Code: Select all

hdmi_safe=1
Also, from your *config.txt* content, it seems you have overclocked the Rpi to 800MHz. It also "could" be a stability problem, which might be leading to blank display.
Change this line:

Code: Select all

arm_freq=800
to

Code: Select all

arm_freq=700
Reboot and see if it works.

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