Two scenarios. First one is during post (which is why I suspect hardware) :
Scenario 1 :
Say system is off. Monitor is off. Turn computer on. Then after that I turn monitor on. The monitor led goes on and it appears like the display will come up; however, it then goes blank a second or two later. Led goes orange (indicating no video or computer off). Then blue - but no display. If I reboot it it'll then come up.
Scenario 2 :
If I go away from computer I always turn monitor off to save power. However, if I'm gone for say 30+ minute (guessing but that's when I usually notice it), I have a very similar problem to the first one. Video comes up for <= 1 second. Then, goes off but the led is blue (indicating there should be video, only.. black screen). I move the mouse and hit keys to make sure it's not, say, a power management issue. I then turn off monitor and back on while moving mouse. Comes on for same duration (<= 1 s).. and I repeat this and eventually it comes back on and stays on - that is, until I go afk again for example.
Things I've noticed in sys log :
Dec 26 08:40:35 triangle kernel: [27530.348552] [drm rm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 189
Dec 26 08:40:35 triangle kernel: [27530.348568] [drm rm_edid_block_valid] *ERROR* Raw EDID:
another day it was similar :
Dec 22 16:02:14 triangle kernel: [55708.920331] [drm rm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 148
Dec 22 16:02:14 triangle kernel: [55708.920338] [drm rm_edid_block_valid] *ERROR* Raw EDID:
(no, I don't use windows. and yes, I have the drivers and everything set up as it should be... only started recently).
Other notes :
I've disabled power management. Same issues.
I've put video card in a different slot. Made sure cables were attached.
One thing I did not try :
a different pci-e cable (If I have a spare; it's a modular psu).
As for psu - 850w, thermaltake. Not a year old if I recall and certainly not much longer if that.
One other thought is the option to invoke video post on (s3 ? one of the sleep modes anyway) resume. Still, it happens during post of the system itself, so I don't know.
Anyone have any thoughts on which it could be ? Video card or monitor ? Something else ?
Nearly forgot. video card specs - geforce 8800 gts 640 oc edition; temp at this moment is 51C.
Montior : 22" viewsonic (think the model is in the vg line an is a bit old, older than the video card).
So basically your videocard is having difficulties identifying the capabilities of your monitor.
If you have a spare monitor that would allow you to determine if its the video card.
Yep - just looked it up (graphics/video isn't my thing). I did not think of it as far as how it would work, though, so thanks for that. For what it's worth I checked edid with a tool (command/program) and it seems fine (so the error is possibly a kernel issue though that's not really an issue during post). But :
EISA ID: VSCa21e
EDID version: 1.3
EDID extension blocks: 0
Screen size: 47.4 cm x 29.6 cm (22.00 inches, aspect ratio 16/10 = 1.60)
Max video bandwidth: 170 MHz
I have a spare (well, my server uses it) but it's unfortunately only vga, not dvi. Given the above though, I'll make sure things are ok settings wise (I'm sure the monitor has a settings panel on it too. maybe it was bumped). So I have a few more ideas to try, but then I may have to look into newer hardware.
Thanks for the suggestion - will work it out one way or another I'm sure.
And I maybe have it (so far seems better). Reset monitor back to defaults. Time will tell. Thanks for the suggestions either way - much appreciated!
Edit: I just came back from about 2 hours away after doing one other thing and it now works. Sometimes the simplest things to check can be it. Despite having recently checked the cable to video card and to monitor already, I did again and made sure it was all in tight. Also, though I don't think it's this, I changed the power cable to the monitor. Considering it would have not come back on after 2 hours of being away, I can only take a guess it's fixed.
Edit 2: Of course, that was in haste. I ended up getting another monitor and no power issues to speak of now. I've seen issues like this before (via google) but obviously while this is one of the possibilities, it's not the only as some say a new video card is needed and some claim other things worked for them. In my case, I did two things (the first just to be sure but realistically I don't think it was necessary). 1) I swapped my pci-e cable power cable in my system (modular psu). 2) attached new monitor to video card. All good after setting up monitor (resolution etc). That was Friday and no problems since. Before that, I saw various issues with the old monitor (issues in the logs and just observations) but in my case the monitor was failing. It was a 4 year old monitor and I use it a lot.