HDMI failure - is it hardware?

[davidmam]

I have two Pi, one is a ref 1 and the other a rev 2. The rev 2 has stopped working on HDMI. I can swap all the parts (card, psu, HDMI from the rev 1 (where it works) to the rev 2 and nothing - no output whatsoever. It has worked, but then just stopped.

How can I test if it is the HDMI port? I can boot an image and SSH in via wireless (or with a bit more effort, attach a serial console)

[BruceP]

The HDMI will not have an output until the boot code is loaded.

If you have the Hynix chip, it may not work with older boot code meant only for the broadcom chipset.

I ran into this issue when a web link directed me to a 2012-02-xx version instead of a 2013-02-xx version. Using the 2013 image allowed me to run with the Hynix chip. I assume that the broadcom chip will work as well.

[rpdom]

If you have the Hynix chip, it may not work with older boot code meant only for the broadcom chipset.

I ran into this issue when a web link directed me to a 2012-02-xx version instead of a 2013-02-xx version. Using the 2013 image allowed me to run with the Hynix chip. I assume that the broadcom chip will work as well.

Just a minor point here (well, not that minor ). All RPi boards use a Broadcom chip. That is the ARM CPU and the GPU - the "heart" of the system. The chip you are referring to is the RAM memory chip which is stuck on top of the Broadcom chip (so you can't see the broadcom chip unless you look very carefully at the jon between the two). The memory chips can be made by Hynix - which, as you correctly state, needs the latest firmware files - or by Samsung which work fine with slightly older firmware.

[davidmam]

I know the board was working with an older distro - it appears to have stopped doing so. I downloaded a new raspbian image and still no joy. Tried the hdmi_safe=1 and still nothing.

[RaTTuS]

http://elinux.org/R-Pi_Troubleshooting# ... put_at_all
try
hdmi_force_hotplug=1
it may be that the RPi / HDMI is just right on the edge of being fine....

[pjc123]

http://elinux.org/R-Pi_Troubleshooting# ... put_at_all
try
hdmi_force_hotplug=1
it may be that the RPi / HDMI is just right on the edge of being fine....

The OP used the hdmi_safe=1 parameter, which actually sets hdmi_force_hotplug=1, so that did not work. The only reason I know this is that yesterday I came across the exact same problem you mentioned with the "edge of being fine" problem.

On my original pi, Model B Rev 1 running an old version of Soft Float Wheezy, when I started it up sometimes I would not get a HDMI display, but a quick reboot before anything important loaded, and the screen would usually come up fine. I just lived with it.

So I received my Model B Rev2 board yesterday and figured all I had to do would be to image the card with the newer Raspbian and just hook up all my previously running hardware and it would be a quick good to go. Wrong ! ; and rebooting was not helping. So I am thinking, here we go, is it the newer operating system or the updated pi hardware. So, I discovered that after putting it into safe mode the display magically appeared (hdmi_safe=1).

Now safe mode sets a pretty much useless resolution which I fixed, but I had a feeling that there was something else going on. So, the hdmi_safe=1 command sets a specific set of parameters, so I set each command one at a time until I found which single command fixed the problem.

These are the parameters that hdmi_safe=1 sets:

hdmi_force_hotplug=1
config_hdmi_boost=4
hdmi_group=2
hdmi_mode=4
disable_overscan=0

It turns out that hdmi_force_hotplug=1 fixed the problem, and I did not have to mess with any of the other commands above, including hdmi_safe=1. Apparently HDMI on my monitor was on the hairy edge of working with the Rev 1 board, but would not work at all with the Rev 2 board. Assuming that it is a monitor related issue and not a pi related issue, I am including the model of my monitor in the event that others come across the same problem.

Monitor: Samsung T220HD

[davidmam]

I tried multiple monitors. It was working until I tried the Plan9 distro (which may have no bearing at all on the situation).

..d