Weird graphics? problem

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Jeffers
Active UBT Contributor 15+ yrs
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Joined: Mon Jul 24, 2006 1:00 am
Location: Halifax, West Yorks.

Weird graphics? problem

Post by Jeffers »

My PC runs 24/7 (of course, for crunching!) but I generally turn the monitor off to save a bit of electricity.
Recently something strange has been happening...
When I turn the monitor back on one of two things happens.
1) I get a display but the resolution has changed downwards, and I have to set it back to normal.
Or 2) I get no display, just a blank screen.
For a while in situation 2 I was doing a reset of the PC but I found that if I logged off ( I worked out what the keystrokes would be so I could do it blind) then I got back to the logon screen and got back in.
Even stranger, after a bit of experimenting I have found that this doesn't occur if I leave the monitor on (it's on display port).
I first thought that it might be a BOINC project causing it as I added some new ones for Sprints. But I'm now back to just Collatz and it's still happening. It's more of an annoyance than anything else, I just leave the monitor on and all is OK but I'd like to know if anyone can offer an explanation.
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Woodles
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Location: Cambridgeshire

Re: Weird graphics? problem

Post by Woodles »

Hi Jeff,

Nothing to do with Boinc, it's a 'feature' of Windows.

Display port (like HDMI) is a plug-and-play interface. When turned off, Windows treats the monitor as being removed, disconnects the desktop and disables the output. It also sets the desktop to the default 800 x 600 resolution. On power on of the monitor, Windows needs to rediscover the hardware, interrogate it to find it's capabilities and change the resolutions as required. Windows also checks at log on as different users could have different desktop settings. Leaving the monitor on (but blanked) skips this process.

Sounds like the last setup isn't being detected from the monitor. Has the cable come loose at either end? Is the resolution you're using not one of the standard ones for the monitor? Is the monitor one you've had for a long time and maybe losing it's capability of storing the last set up? (CMOS battery died, EEPROM cycles exhausted?)

Alternatively, this post (https://sites.google.com/site/ebobster/ ... rtblanking) explains how to turn off the Windows hardware autodetect and use a file to store the required resolution for the monitor. Only works for NVidia though.

Condition 2 may need additional monitor power cycles if Windows isn't detecting the monitor at all.

Mark
chriscambridge
Active UBT Contributor 1+ yr
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Location: UK

Re: Weird graphics? problem

Post by chriscambridge »

Not sure if this would help, but I use HDMI dummy plugs so I can run at full resolution using VNC (remote access). Then if I need to display locally (to access the BIOS or whatever) I then just swap the dummy plug for the monitor HDMI cable.

You can pick these up for about £1 each on Ebay UK.

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Jeffers
Active UBT Contributor 15+ yrs
Posts: 1627
Joined: Mon Jul 24, 2006 1:00 am
Location: Halifax, West Yorks.

Re: Weird graphics? problem

Post by Jeffers »

Thanks for that guys.
Regarding the monitor, it is one I inherited from my son. He's quite the geek, gets the latest of most gadgets and passes on the "old" stuff to the family. This is why my daughter has the next to latest I-phone and all the grand-kids have I-pads of various flavours.
I'm not interested in Apple stuff but when he offered me the monitor it was a "yes please". I think he'd had it sat around for a while so the scenario of it not holding settings is plausible. It is also running at its recommended resolution. I'll reseat cables and stuff but the setup I've got hasn't changed in a while and doesn't get disturbed (if you discount the occasional exploration by one of the cats). As I said, it's more of an irritation than anything else, I'm happy to just leave everything on 24/7. I'll see if I can find a quick way of turning off the display when not in use. Windows just seems to ignore any of the power saving settings for turning off the display and turning the brightness down involves a trip through the monitor's menu, which is a bit clunky....
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Woodles
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Joined: Thu Dec 20, 2007 12:00 am
Location: Cambridgeshire

Re: Weird graphics? problem

Post by Woodles »

Hi Jeff,

If you just want to blank the screen, create a batch file with the following:

Code: Select all

start /min /wait C:\Windows\System32\scrnsave.scr -s
This fires up the screen saver with a blank output. Resume by pressing any key.
Also assumes your windows installation is in "C:\Windows", change as necessary.

If you want the monitor to switch off as well:

Code: Select all

C:\Windows\System32\powercfg.exe -Change -monitor-timeout-ac 1
C:\Windows\System32\powercfg.exe -Change -monitor-timeout-dc 1
start /min /wait C:\Windows\System32\scrnsave.scr -s
C:\Windows\System32\powercfg.exe -Change -monitor-timeout-ac my1
C:\Windows\System32\powercfg.exe -Change -monitor-timeout-dc my2
Sets the display timeout to be one minute, blanks the screen, monitor turns off after a minute.
Waits for a keypress, sets the display timeout back to what you prefer ("my1" and "my2")
The "-ac" settings are for when the computer is on the mains, the "-dc" settings are for battery (probably not needed)

Only thing to be careful of is that it's waiting for a keypress or mouse movement to wake up, keep them cats away! :lol:

Mark
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