Input Signal Out of Range - Blank Screen

**Freehold Fred** · 11-15-2006, 01:06 PM

OS XP PRO

'Puter works fine in other locations, does not work at this one location.

Cornea CT1501 LCD Monitor displays error Input Signal Out of Range and goes blank.

Can't find online manual for monitor.

Booted into Safe Mode: Unable to change any settings

Did System Restore; seems to work now but will have to restore QuickBooks. Data okay.

What happened? What does Input Signal Out of Range Mean re: monitor? I thought that it might refer to wireless adapter and this 'puter does have a wireless adapter. We checked video settings and refresh rate is 75Hz, which is optimal for this monitor. Rez is 800x600, which is not optimal.

Monitor has Menu button. Looking for autodetect settings.

Any clues as to what is going on?

**dbarrow** · 11-15-2006, 01:23 PM

Out of range is usually a refresh rate that is not supported for the chosen resolution.
Hard to see without a monitor!

You should be able to change the vid settings in safe mode as safe will not load the vid driver.
I remember going through this before!

**kelly** · 11-16-2006, 09:47 AM

I think Doug is correct. I've seen this on a couple of newer machines using older monitors that can't handle the video setting. One time it was kids who brought up Display Properties, Settings and set it to max resolution. However, the monitor was unable to handle the resolution.

I don't know that you can reset it using Safe Mode. What I did (in both cases) was to put a newer monitor (that could handle the higher the high resolution) on the computer and reset to lower resolution.

- tony

**Freehold Fred** · 11-22-2006, 12:38 AM

Yes, that is what i believe is the problem --- refresh rate. Unable to change refresh rate in Safe mode. System Restore saved the day on this one!

Originally Posted by dbarrow

Out of range is usually a refresh rate that is not supported for the chosen resolution.
Hard to see without a monitor!

You should be able to change the vid settings in safe mode as safe will not load the vid driver.
I remember going through this before!

**Rich-M** · 11-22-2006, 01:21 PM

Strange if that is an LCD they normally work at refresh rate of 60....

**dbarrow** · 11-22-2006, 02:08 PM

Ah! but... refresh rate ranges for particular resolutions are set as reg keys.
Therefore, if you had somehow set (or XP decided on its' own to set from a generic pnp) a range that was off for the default resolution, then it would be out of range.

Plug and Play can be a PITA in many cases!
Whenever I update the new monthly ATI CAT driver, Windows (in its' infinite wisdom) decides to change the monitor to default plug and play in Device Manager.
I use 1280x1024 for my desktop and this will reset the refresh rate to 100. While that is still in range for this monitor, the correct setting is 85.
In order to correct this, I have to (following the reboot) go into Device Manager/Monitor and Update Driver, choosing the mnfr specific .inf file for the monitor. While the pnp settings will work, the specific .inf for this monitor yields considerably better performance and correct ranges for all but one resolution.
This seems to be a defect in the generic pnp settings in XP that was later corrected by the mnfr with a specific monitor .inf. that is still unsigned.

A handy utility I always use is ReForce.
While you can define the refresh rates at particular resolutions through CAT control panel and ATI Tray Tools,
ReForce is a handy utility that scans the monitor (.inf) and lists all resolutions and refresh rates in a table where you can easily set each one.
This changes the associated reg keys and any further resolution changes will bring up the correct refresh rate.
ie: I run my games at 1600x1200 and if I don't do this, it likes to load 3d apps at 100 instead of 85 which distorts the screen.

If I recall correctly, I used this to fix an out of range problem once before when a driver update farkled the ranges. I believe ReForce runs in Safe Mode.
Safe Mode loads generic VGA video in 800x600 and does not load the more specific reg keys you have set in XP normal mode and advanced video settings.

It is always advisable to go to the mnfr web site and look up your monitor. See if there is a specific monitor .inf for it and download it. A specific .inf may contain info that was not included in the generic pnp of XP and may have since been updated. It may not be WHQL signed.
Always use the mnfr specific .inf when available.
While you are there, look up the refresh rate table for the particular model and print it. Store for future reference.
Whenever you change vid drivers, you may have to go through this manual process of updating to the correct .inf and running ReForce to set the correct refresh rates for each resolution.

**Freehold Fred** · 11-23-2006, 12:39 AM

The problem is that the computer was taken off-site for repair w/o the monitor. Then when it returned to the original monitor, it did not work. Apparently, the tech must have had a completely different monitor that got settings locked in, because it worked off-site, not on-site with the original monitor.

Originally Posted by mylanta

Strange if that is an LCD they normally work at refresh rate of 60....

**dbarrow** · 11-23-2006, 11:24 AM

Well, that would certainly do it!
When he booted it up with a different monitor, the faithful hardware wizard kicked in detecting the PnP settings and adjusted XP to the new monitor settings.
When returned to the original, they were out of range and XP failed to detect that monitor and adjust back to the correct settings. The original monitor may not have been PnP.