Projector and TV receives VGA-signal but doesn't realize it

[TBJ]

Hey

I'm having the above mentioned problem with my father’s laptop.

He's a teacher so we bought the laptop so he could show powerpoint-presentations on projector, but the laptop doesn't work with all projectors. :-(

The output is received by the external screen/projector but the projector doesn't realize that there is input. In the classroom that my father teaches this spring the projector will for like 5 or 10 seconds show the pc-screen and then turn off.

We have a Sony-TV with VGA-plug so I tried connecting the laptop to our TV (different cable and different “external screen”). When I connect the cables, the TV doesn't automatically realize that there is a computer-input. But if I force the TV to show the "VGA-channel" the computer screen is shown perfectly on the TV. I believe the problem is similar on the projector, i.e. the screenpicture is sent trough the cable, but there's no "information" that there is a picture.
To test if the computer receives information on the cable I tried the setting that the screen should only be seen on the external screen. As soon as I plug in the cable to the PC the screen goes blank, so the PC recognizes the cable.

From PB's support homepage I tried installing/reinstalling the video-driver but unfortunately it didn't help.
(VGA AMD VGA Driver (Radeon HD 6650M) 8.783.2 130.3 MB 2011/01/20)

Have any of you any idea on how to solve the problem or at least where the problem is. Is it a win7 problem, a problem with the hardware (the VGA-plug on the laptop) or is it a driver problem?
And by the way: The computer is up to date with win7 updates.

Thank you very much in advance!

Thomas

 

[Maguscreed]

Have you investigated the devices, it could be something as simple as a resolution setting.
It's possible the unit you have and the one he's using outside use different native resolutions.

 

[TBJ]

Have you investigated the devices, it could be something as simple as a resolution setting.
It's possible the unit you have and the one he's using outside use different native resolutions.

I'm not sure how it could be a resolution setting, as I can see the screen on the TV when I force the TV to the "VGA-channel", but I have tried changing the screen-setting to other resolutions without any help.

 

[Maguscreed]

Well the tv will have to be set to the proper input obviously.
I'm not aware of any that will automatically jump to their vga port when they detect a connection.

 

[TBJ]

I'm sorry, you're right.

Just to clarify what I meant with TV-thing:

According to our TV's manual:
"Auto
Displays the icon and name only when the equipment is
connected (except for AV1 or AV2 inputs).

Always Display
Always displays the icon and name regardless of whether or
not the equipment is connected."

http://pdf.crse.com/manuals/4136111141.pdf ("AV Preset")


We use the auto-setting. When there is a computer connected through VGA then the VGA-input is visible as one of the "External Inputs". This works with my own "Win7 home premium 64" laptop, with my old win vista laptop and today I found out my father's old win2k laptop works this way as well.

But the TV doesn't recognize my father's new computer. But if I change the setting to "Always Display" and go to this external input then my fathers screen shows perfect on the TV.

I'm sorry, but it's a little difficult explaining especially because English isn't my native language.

But thank you very much for your help!

 

[Maguscreed]

other than setting the tv for 'game' I can't think of anything else that may help.

 

[TBJ]

OK, thanks for your help anyway. I'll keep looking for a solution. If anyone have an idea how to solve the problem, please let me know.