no boot when hdmi connect

Hi,

     When not using HDMI, does it boot and you SSH or use it headless? I have had some troubles where the monitor/TV with HDMI does not recognize my Pi because of cables or HDMI standards like CEC incompatible issues.To learn more read the CEC section and try it from Raspberry Pi - Robert Eklund's homepage.

Cheers,

Clem

Hi,

When not using HDMI it starts always.

I tried an other monitor (ASUS) and it worked.

It seems that the problem only appears on my Samsung-Monitor (SynchMaster SA300) and only when it is in standby

I have no glue what may happen in standby mode to raspberry.

Best regards

Stefan

I don't have a ready solution for you, but...

The video-source can ask the monitor what resolutions it supports. It is supposed to be able to do that even when the monitor is in standby. If the Samsung shows a different behaviour if it is in standby versus when it is not, it seems that this is not working.

Now, with a "weird" HDMI monitor attached, in principle the Raspberry should still start, except maybe with a "weird" monitor configuration, maybe even "no screen" but it should at least start up and be reachable over the network. If that doesn't happen, there is also something weird going on with the 'pi.

Are you DVI or VGA?

NPUTS
VGA	Yes
DVI	Yes

Clem

PS Did I say mine is a Samsung that gives me trouble? I will need to play with. Maybe the brand and Pi don't play well.

Hi Roger,

the raspberry simply did not boot at the samsung monitor, red led is on, green led remains off.

So I guess the monitor hit the raspberry in some way.

I am going to check what signals may pass the HDMI/DIV. Maybe the I get a clue what is going on.

For me I can switch to Asus monitor but I also want to create a search machine findable way for people who do not have multiple monitors but the problem.

Best Regards

Stefan

Hi Clem,

I am using an HDMI converting to DVI-cable

(Asus: HDMI to HDMI)

Best Regards

Stefan

Stefan, as already alluded to the problem most probably lies with the implementation of CEC  failing this it's the power from the HDMI partially powering the RPI  which leaves it in an undefined state which can't be recovered from. Unfortunately that's merely acknowledging that this problem exists, if you have a VGA input on that Syncmaster you can use a HDMI-VGA adaptor to get you out of that problem. In the UK they are around £6 and worth a try.

John

back when we had a schematic of the 'pi, there was a diode to prevent the pi getting power from the HDMI-5V.

Still plenty of scope for the CEC to screw things up ... using an HDMI to VGA adaptor was just a bodge to get break the HDMI/DVI connection and just get plain video

Speaking of which. CEC is as far as I know a HDMI thingy. The CEC if even available, will be "broken" by the DVI adapter as well. I was suspecting problems with the i2c-like signals between the graphics "card" and the monitor (I forget at the moment what they are called.. [UPDATE: "EDID"]). These have existed since VGA, and as far as I know, the PI will interrogate the real monitor even when a VGA- or DVI adapter is used.