sansjunk
Posts: 7
Joined: Fri Dec 28, 2012 12:27 pm

Blank HDMI->DVI display

Sat Dec 29, 2012 5:42 pm

Hello!

Just got my Pi yesterday after waiting for month and since then I have been breaking my head trying to get the Pi to display on the only HDMI/DVI display I have! (its a ViewSonic VA1928wm LCD screen with VGA and DVI input). I am using an HDMI cable with a HDMI->DVI adapter at the display end.
Here is a summary of where I am:
  1. The Pi is booting fine since I can SSH into it and also tried the TV out connector which displays fine but the quality is bad. I initially had boot trouble with a slower SD card but that is sorted out now.
  2. The monitor, cable and adapter are all fine since the display works fine when connected to my desktop graphics card (HDMI out).
  3. The Pi is able to detect the HDMI monitor (saw the event using "tvservice -M" command) and monitor too is able to detect HDMI input since it goes off standby after Pi just starts up (the power/standby LED on the monitor goes off). However there is no display - the screen is blank.
  4. I tried various settings in the config.txt: deleted it, set hdmi_safe, config_hdmi_boost (to 2, 4, 7), etc but nothing helps fix the problem.
  5. I tried to manually switch on the HDMI using the various supported modes (using "tvservice -e" command) but the display is still blank.
  6. The Pi is able to successfully figure out that the correct resolution is 1440x900.
I am unable to attached files (keeps saying none of the extensions are allowed) so I have pasted the parsed edid below.

If someone can kindly help out it'd be great. I am going nuts on this and unfortunately this is the only monitor I have to use :-(

Parsed EDID information:

Code: Select all

Enabling fuzzy format match...
Parsing edid.dat...
HDMI:EDID version 1.3, 0 extensions, screen size 41x26 cm
HDMI:EDID features - videodef 0x80 !standby !suspend active off; colour encoding:RGB444|YCbCr444|YCbCr422; sRGB is default colourspace; preferred format is native; does not support GTF
HDMI:EDID found monitor S/N descriptor tag 0xff
HDMI:EDID found monitor range descriptor tag 0xfd
HDMI:EDID monitor range offsets: V min=0, V max=0, H min=0, H max=0
HDMI:EDID monitor range: vertical is 50-75 Hz, horizontal is 24-82 kHz, max pixel clock is 140 MHz
HDMI:EDID monitor range does not support GTF
HDMI:EDID found monitor name descriptor tag 0xfc
HDMI:EDID monitor name is VA1928wm
HDMI:EDID found preferred DMT detail timing format: 1440x900p @ 60 Hz (47)
HDMI:EDID established timing I/II bytes are BF EF 80
HDMI:EDID found DMT format: code 4, 640x480p @ 60 Hz in established timing I/II
HDMI:EDID found DMT format: code 5, 640x480p @ 72 Hz in established timing I/II
HDMI:EDID found DMT format: code 6, 640x480p @ 75 Hz in established timing I/II
HDMI:EDID found DMT format: code 8, 800x600p @ 56 Hz in established timing I/II
HDMI:EDID found DMT format: code 9, 800x600p @ 60 Hz in established timing I/II
HDMI:EDID found DMT format: code 10, 800x600p @ 72 Hz in established timing I/II
HDMI:EDID found DMT format: code 11, 800x600p @ 75 Hz in established timing I/II
HDMI:EDID found DMT format: code 16, 1024x768p @ 60 Hz in established timing I/II
HDMI:EDID found DMT format: code 17, 1024x768p @ 70 Hz in established timing I/II
HDMI:EDID found DMT format: code 18, 1024x768p @ 75 Hz in established timing I/II
HDMI:EDID found DMT format: code 36, 1280x1024p @ 75 Hz in established timing I/II
HDMI:EDID standard timings block x 8: 0x9500 950F 8180 8140 714F 0101 0101 0101 
HDMI:EDID found DMT format: code 47, 1440x900p @ 60 Hz (16:10) in standard timing 0
HDMI:EDID found DMT format: code 48, 1440x900p @ 75 Hz (16:10) in standard timing 1
HDMI:EDID found DMT format: code 35, 1280x1024p @ 60 Hz (5:4) in standard timing 2
HDMI:EDID found DMT format: code 32, 1280x960p @ 60 Hz (4:3) in standard timing 3
HDMI:EDID found DMT format: code 21, 1152x864p @ 75 Hz (4:3) in standard timing 4
HDMI:EDID filtering formats with pixel clock > 162 MHz or h. blanking > 1023
HDMI:EDID best score mode initialised to DMT (4) 640x480p @ 60 Hz with pixel clock 25 MHz (score 0)
HDMI:EDID best score mode is now DMT (4) 640x480p @ 60 Hz with pixel clock 25 MHz (score 36864)
HDMI:EDID best score mode is now DMT (5) 640x480p @ 72 Hz with pixel clock 31 MHz (score 44236)
HDMI:EDID best score mode is now DMT (6) 640x480p @ 75 Hz with pixel clock 31 MHz (score 46080)
HDMI:EDID best score mode is now DMT (8) 800x600p @ 56 Hz with pixel clock 36 MHz (score 53760)
HDMI:EDID best score mode is now DMT (9) 800x600p @ 60 Hz with pixel clock 40 MHz (score 57600)
HDMI:EDID best score mode is now DMT (10) 800x600p @ 72 Hz with pixel clock 50 MHz (score 69120)
HDMI:EDID best score mode is now DMT (11) 800x600p @ 75 Hz with pixel clock 49 MHz (score 72000)
HDMI:EDID best score mode is now DMT (16) 1024x768p @ 60 Hz with pixel clock 65 MHz (score 94370)
HDMI:EDID best score mode is now DMT (17) 1024x768p @ 70 Hz with pixel clock 75 MHz (score 110100)
HDMI:EDID best score mode is now DMT (18) 1024x768p @ 75 Hz with pixel clock 78 MHz (score 117964)
HDMI:EDID best score mode is now DMT (21) 1152x864p @ 75 Hz with pixel clock 108 MHz (score 174298)
HDMI:EDID DMT mode (32) 1280x960p @ 60 Hz with pixel clock 108 MHz has a score of 172456
HDMI:EDID best score mode is now DMT (35) 1280x1024p @ 60 Hz with pixel clock 108 MHz (score 182286)
HDMI:EDID best score mode is now DMT (36) 1280x1024p @ 75 Hz with pixel clock 135 MHz (score 196608)
HDMI:EDID best score mode is now DMT (47) 1440x900p @ 60 Hz with pixel clock 106 MHz (score 5258280)
HDMI:EDID DMT mode (48) 1440x900p @ 75 Hz with pixel clock 136 MHz has a score of 219400
HDMI:EDID preferred mode remained as DMT (47) 1440x900p @ 60 Hz with pixel clock 106 MHz
HDMI:EDID has only DVI support and no audio support
edid_parser exited with code 0

sansjunk
Posts: 7
Joined: Fri Dec 28, 2012 12:27 pm

Re: Blank HDMI->DVI display

Sat Dec 29, 2012 5:50 pm

Sorry I forgot to mention few more points:
  1. I read in the troubleshooting sticky that a low voltage can cause HDMI to fail to display. This isn't the situation in my case since I am using a good quality PS with a USB powered hub to power the Pi. The voltage between TP1 and TP2 is 4.93 volts.
  2. When the Pi supplies HDMI signal to the monitor, the monitor front buttons become unresponsive along with the power LED of the monitor turning off. If I disconnect the HDMI cable then the front buttons start working again!

sansjunk
Posts: 7
Joined: Fri Dec 28, 2012 12:27 pm

Re: Blank HDMI->DVI display

Sat Dec 29, 2012 5:59 pm

Sorry, few more things! I have tried so many things to get the HDMI working and having difficultly recollecting them all at once!

Thinking I may have an older GPU firmware I updated everything using "rpi-update" tool and that didn't help either. Here is output of some commands:

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$ vcgencmd version
Dec 28 2012 11:22:54
Copyright (c) 2012 Broadcom
version 359904 (release)

Code: Select all

$ uname -a
Linux raspberrypi 3.6.11+ #346 PREEMPT Fri Dec 28 00:50:33 GMT 2012 armv6l GNU/Linux

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$ cat /proc/cpuinfo
Processor       : ARMv6-compatible processor rev 7 (v6l)
BogoMIPS        : 697.95
Features        : swp half thumb fastmult vfp edsp java tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xb76
CPU revision    : 7

Hardware        : BCM2708
Revision        : 000f
Serial          : 000000004e540443
[email protected] ~ $

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5398
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: Blank HDMI->DVI display

Sat Dec 29, 2012 8:10 pm

If hdmi_safe=1 doesn't give a picture, then I don't think you'll get one with any settings.

You really need a "swap" test to identify the problem. Do you know someone with a working Pi?

Either the Pi, the monitor or the cable is problematic, and you need to swap each out to identify the problem.

sansjunk
Posts: 7
Joined: Fri Dec 28, 2012 12:27 pm

Re: Blank HDMI->DVI display

Mon Dec 31, 2012 3:56 am

dom wrote:If hdmi_safe=1 doesn't give a picture, then I don't think you'll get one with any settings.

You really need a "swap" test to identify the problem. Do you know someone with a working Pi?

Either the Pi, the monitor or the cable is problematic, and you need to swap each out to identify the problem.
Hi dom,

Thanks for the reply. I was hoping you would catch this thread since your help seems to have fixed many issues related to HDMI (yes, I read through quite a bit before posting my issue!).

I don't know of anyone else with a Pi though I am trying to convince a few of my friends to get one ;)

The monitor, cable and the HDMI->DVI adapter all work fine when I connect the monitor to my desktop PC (it has a graphics card with HDMI out). So as the next step I was planning to boot my desktop into Linux and see what settings the graphics card is using to light up the display - using "tvservice").

Another test I can do is to try my Pi at a friend's place who has a LCD TV with HDMI input.

Anything else I can do to diagnose the problem?

Regards,
Santosh

Geniearse
Posts: 1
Joined: Wed Jan 02, 2013 8:36 pm

Re: Blank HDMI->DVI display

Wed Jan 02, 2013 8:44 pm

I bought a Raspberry kit off EBAY and everything worked fine on a TV with HDMI, but trying it on a HP1940 monitor with HDMI DVI convert using the same cable gave a blank screen.
I bought the cheapest HDMI cable off EBAY and found it to work without problem.
It would appear not all cables are the same!

sansjunk
Posts: 7
Joined: Fri Dec 28, 2012 12:27 pm

Re: Blank HDMI->DVI display

Thu Jan 03, 2013 3:59 am

Geniearse wrote:I bought a Raspberry kit off EBAY and everything worked fine on a TV with HDMI, but trying it on a HP1940 monitor with HDMI DVI convert using the same cable gave a blank screen.
I bought the cheapest HDMI cable off EBAY and found it to work without problem.
It would appear not all cables are the same!
So you're saying replacing the HDMI cable with a cheaper one from ebay worked for the DVI display? Is that a HDMI-DVI cable or are you using a HDMI cable with a HDMI->DVI adapter?

Today I tried my Pi on a friend's HDMI TV (Samsung) and it worked flawlessly. Same Pi, same cable! I just don't get why its so finicky :(

So based on what I have tried so far everything works fine in some combination but not how I want it!

Pi, its HDMI out and HDMI cable ==> Works, checked out on friend's HDMI TV
DVI monitor, HDMI->DVI adapter ==> Works, checked out with my desktop PC

Pi + HDMI cable + HDMI->DVI adapter + DVI monitor ==> DOES NOT WORK! WHY???

This is driving me nuts!

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