My old CRT monitor (Samsung 957DF) finally completely died yesterday so I had to replace it.
Several months ago I bought a relatively cheap TFT monitor (Acer V223HQ Bb) and while my Windows 7 installation was still fresh, I could switch between the two monitors (Samsung CRT and Acer TFT) without problems. Windows would always recognize which monitor is hooked on and display the proper picture.
But now I can't make this new Acer V22HQ monitor work with my PC. It only works in the Safe Mode and it displays the picture in BIOS and while Windows 7 is loading, but as soon as Windows 7 wants to show the Login Screen (for the administrator) the screen on this monitor goes blank and the monitor displays the message "NO SIGNAL". Since without picture I can't know what I am doing, I have to restart and go into the Safe Mode.
However, in the Safe Mode it's not possible to change the monitor driver
easily because it displays some default monitor driver ("Generic PnP Monitor - On").
At one point I thought that maybe Win 7 thinks that I still use the old CRT Syncmaster monitor and wants to use that driver with the TFT monitor, but now it doesn't seem that's likely. I tried to attach a VERY old Philips CRT monitor on this PC and Win 7 recognized it immediately and put the proper drivers
. Why can't it do the same for Acer TFT?
While I had Philips CRT attached today, there were two monitor drivers in Device Manager: "Philips CT012" (I think) and "Generic PgP Monitor". There was no trace of Syncmaster.
Now in the Safe Mode and with Acer TFT monitor attached, I can see two drivers in Device Manager (provided I click Show Hidden Devices):
Generic Non-PnP Monitor
Generic PnP Monitor
and it seems that both of them are not working (when I look at the properties it says: "Currently, this hardware device is not connected to the computer. (Code 45) To fix this problem, reconnect this hardware device to the computer.")
One more piece of info that may be important: During one session in the Safe Mode, I saw an application in the Start Menu which was named "Remove old monitor drivers" (not exactly but that was the point). It was among the big icons in the start menu, as if Windows 7 "knew" that it had to be done. I launched it, pressed OK and it said something like "Done, but several .COM files/programs may still be running for this monitor driver which may be a problem."
Again, the TFT monitor worked fine some 2 months ago, and the only thing that I know was different in Windows 7 was that at the time it had a "Generic PnP monitor" driver which was since then updated to "Synmaster" (for my previous CRT monitor). Switching between the two monitors was seemless and could be done even while both PC and monitor were turned on.
Could anyone help me with this problem? Is this really only due to a bad driver, or perhaps something needs to be fixed with hardware?
I've been trying to fix it for the entire night without success.
P.S. My graphic card is ASUS EAH5750 Series (Radeon HD 5750)