Wandboard Quad black screen

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Wandboard Quad black screen

Postby rhcp » Thu Sep 11, 2014 8:17 pm

Dear Wandboard users,

I have a Quad board where I like to boot a prebuild linux image. But when I power on the board with the image sd card the screen (HDMI port) remains black. I did the following steps:

I have
1.) Downloaded Yocto Qt5 image from Wandboard.org/downloads to my Windows machine
2.) Unziped the image
3.) Started Win32DiskImager and wrote successfully the image to my 4GB ScanDisk micro SD card
4.) Connected my screen over Hdmi with the board
5.) Placed SD card in the board slot and powered the board with the delivered 5 V power adapter

The screen stays black. I have repeated the steps with the Ubuntu and Yocto without Qt and without success. The two green Led's are on.

How can I get booted a prebuild linux image on the Quad board?

Best regards,
rhcp
rhcp
 
Posts: 2
Joined: Thu Sep 11, 2014 7:59 pm

Re: Wandboard Quad black screen

Postby rug » Sun Sep 14, 2014 12:15 am

Hi rhcp,
I am having the exact same problem with my quad wandboard, only I'm using Android.
However, I was able to confirm that my system is booting. Input and output are by default routed to the serial port (115.2 kbaud, 8 bits, 1 stop bit, no parity).
If yocto is configured the same way, all you need is a null modem cable.

I probed the signal pins on the HDMI connector with a scope and I found that both clock and data are there. I am measuring a clock frequency of about 76 MHz with a 0.5 V swing (single ended), which seems about right.
Still, my screen stays dark. My monitor is an older DELL with a DVI port. I have tried another monitor with the same result, so it seems that it's probably not the monitor. It could be the cable (a really cheap one), but I don't have a good way to test it.
Have you made any progress meanwhile?
Thanks,
rug
rug
 
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Re: Wandboard Quad black screen

Postby rhcp » Sun Sep 14, 2014 7:57 pm

Hi rug,

thank you very much for your response. Currently I hadn't had the time to return to my board. But my next step will be to build a bootable SD card with the ArchLinux as it is described here:
http://archlinuxarm.org/platforms/armv7 ... s-ui-tabs2
I'm not a hardware professional I'm much more interested in programming. Hopefully I can get the board up and running... .

I'll be back when I have some news.
Best regards,
rhcp
rhcp
 
Posts: 2
Joined: Thu Sep 11, 2014 7:59 pm

Re: Wandboard Quad black screen

Postby Tapani » Mon Sep 15, 2014 4:32 am

rug,

DVI will likely not work. The Freescale HDMI driver expects to read an EDID with mode information -- which requires real HDMI.


rhcp,

can you check with a serial cable ("debug console") if your board is in fact booting, and you are having some display issue?
Tapani
Site Admin
 
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Re: Wandboard Quad black screen

Postby Johnm » Thu Jun 04, 2015 5:33 pm

I have the same issue. Just received Wandboard and want to test it out. I use Android KK img and wrote to sdcard. I use HDMI cable with 5V DC but nothing show up on screen.
Johnm
 
Posts: 1
Joined: Thu Jun 04, 2015 5:32 pm

Re: Wandboard Quad black screen

Postby arj2000 » Sun Nov 22, 2015 7:51 pm

Tapani wrote:DVI will likely not work. The Freescale HDMI driver expects to read an EDID with mode information -- which requires real HDMI.

You're right.

I tested (several times) my Quad with my HDMI&DVI screen and this are my results:

  • HDMI (WB) to HDMI (Screen) works flawless
  • HDMI (WB) + DVI Adapter to DVI (Screen) only shows logo, and then black screen until power down.
arj2000
 
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Joined: Wed Jul 09, 2014 4:48 pm

Re: Wandboard Quad black screen

Postby Physikus » Tue May 10, 2016 11:36 am

Hallo!
Can these missing Information be put into a Config file which is read by the Kernel /by the X Window System? :?:
Tapani wrote:rug,

DVI will likely not work. The Freescale HDMI driver expects to read an EDID with mode information -- which requires real HDMI............
Physikus
 
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