Faulty HDMI?

5 posts
by ActionHank » Tue May 08, 2012 6:30 pm
Hey guys, i received my raspberry pi this morning, but after a couple of reboots and successful boot ups, my  monitor stopped receiving the signal from the Pi.

I've tried 3 different monitors, 2 hdmi cables, couple of chargers and even played around with the config.txt, by using hdmi boost, hdmi_drive etc. without any luck. I also tried arch thinking that the debian image might be corrupt, but still no luck :(

Is it possible that i shorted out the Pi while disconnecting the power connector? The voltage on the multimeter reads 4.95V and the OK and PWR led are on.


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by dom » Tue May 08, 2012 6:36 pm
Can you try composite output? Would be useful to know if it is booting properly.
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by ActionHank » Tue May 08, 2012 7:02 pm
I just managed to successfully connect to my Pi through SSH. That means that my Pi is working, but the HDMI is not :(
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by Steady_Bear » Tue May 08, 2012 8:28 pm
Unplugging the power shouldn't damage the chips, as that is the general power off method (I think :) ) the HDMI port should also be hotplug-able.

Once ssh'd in please could you check dmesg and /var/log/Xorg.0.log (or similar name).

Have a quick look to see if you can spot anything which looks like a complaint. Under the Xorg log it should be flagged as (EE) or (WW) so pretty obvious. Not sure how well you know Linux so type, after a fresh reboot and login:

cat /var/log/Xorg.0.log (just type the X and hit TAB key).


Given you've tried Arch I'm guessing the above may be a little patronising, but meh.

Please can you confirm if you are able to test on composite.
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by Phil Spiegel » Wed May 09, 2012 7:15 am

Steady_Bear wrote:   the HDMI port should also be hotplug-able.

Although I don't yet have my Pi, I don't believe this statement is correct !

This is (1) because the HDMI involves 2-way communication (so the monitor needs to be powered first, or have circuitry powered via the connection, to respond from), and

(2) because, if on booting it does not find the hdmi (communication), it will automatically revert to Composite - and this has no mechanism to change back until a Power-Off Reset

Moral? - always have a composite connection on hand when testing.
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