0

I get no signal after boot, yet when I hit the reset button the boot screen shows. What could be the problem?

thanks

monitor: lg flatron W2246T

ps: this is no duplicate as I get no black screen when I hit the reset button...

xrandr output

Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 4096 x 4096 VGA-0 disconnected (normal left inverted right x axis y axis) DVI-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 477mm x 268mm 1920x1080 60.0*+ 1680x1050 60.0
1280x1024 75.0 60.0
1152x864 75.0
1024x768 75.1 60.0
800x600 75.0 60.3
640x480 75.0 60.0
720x400 70.1
S-video disconnected (normal left inverted right x axis y axis)

  • 1
    Doesn't seem like a duplicate, aaaa (what a horrid name) please update your question to reflect monitor type and let us know if you can test with another monitor. – coteyr May 20 '13 at 23:19
  • hi. monitor is a lg flatron W2246T. Unfortunately its my only one with a dvi.... – aaaa May 21 '13 at 10:30
  • How are you connecting? What port is in use. Is it HDMA or DVI or VGA etc? – coteyr May 22 '13 at 12:16
  • it's connected via dvi – aaaa May 22 '13 at 13:59
  • So you have a second monitor? I have an idea but you will have to test a command via ssh or type it in via a second screen. – coteyr May 22 '13 at 14:01
0

Older video cards may fail to produce a good quality high resolution image on DVI. Most likely because of frequency instability (?). Default modeline for 1920x1080 results in a very high frequency that RAMDAC (?) on your video card fails to operate at.

You can try to reduce blanking time (RBT) and as a result lower frequency. You have to add new modelines with xranrd as described here. Instead of using cvt or gft, I suggest to use umc. The reason for this is that it can calculate modeline for lower refresh rate with --rbt, e.g. my monitor supports as low as 49.9 Hz refresh rate. cvt would insist on multiples of 60Hz.

Note on comment reply about LVDS... according to your output you should use DVI-0 when adding and setting new modelines.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.