Laptop connected to Projector - image pixellated?

[witch]

I have just built an old laptop up for use as a spare and all seemed well - I cross-checked it with another of the same breed and all drivers etc are present.
However, when I hook it up to a projector all images (background, school logo, icons etc) are pixellated.
If I connect it to an external monitor everything is absolutely fine.
I have tried it on two projectors with the same result.
Can anyone explain what is going on here?
It is a old HP Compaq nx 7400 running Windows XP. Resolution is 1024x768 - exactly as it is on the working machine.

[plexer]

Have you tied it on something like 800 x 600?

Ben

[witch]

Yep - still the same

[plexer]

Ok following on from that and my misspelling have you tied it to a brick and thrown it in the river

What refresh rate is it using when connected to the projector?

Also have you tied one of your others of the same breed to see if they exhibit the same issue?

Ben

[witch]

Others of the same breed are fine and I have set the refresh rate to whatever it is on the identical working machine (cant remember it now)
I'll just tie a brick round it now, but can I throw it in the sea please?

*edit: 60hz is the only option I have

[plexer]

Ok wierd and could just be a laptop that doesn't want to play nicely, any chance you can just swap it with one of the others permanantly?

Ben

[plexer]

Are you running it on mains or battery?

If mains have you tried it on battery only allthough I don't think that will have any effect in this instance.

Ben

[witch]

It was on the mains in one room I tried and on battery in the other - no change I'm afraid. I can't swap it out as I have absolutely no other laptops. I want to know what is going on with this one!

[plexer]

You said you had others of the same recipe that you'd tried can't you just swap it for one of those?

Is this with vga output only or vga + laptop panel?

Ben

[witch]

Nope - I only have one other free that is earmarked for supply. This one is for the cover supervisor/htla to use on a daily basis.

[glennda]

which have you set first?

laptop + monitor or monitor + laptop?


Try with monitor first - i've seen this on a few machines where they just can't give out enough on the second.

[witch]

Not sure if pixellation happens when just projector is chosen - I think so, will check
It is currently set to notebook and monitor - I will swap it over and have a look

[Marc-Engineer]

What make and model of projector is it and is the laptop a Dell?

Marc
Projector engineer

[plexer]

It is a old HP Compaq nx 7400 running Windows XP. Resolution is 1024x768 - exactly as it is on the working machine.

Nope it's an HP

Ben

[salbematch]

Have you tried connecting the laptop directly to the projector with a known good VGA cable? I'm assuming that there is a 'plumbed-in' VGA cable from the projector down to the IWB.
Also, have you tried cycling through the display modes with the laptop connected? i.e. ltop + monitor ==> monitor only ==> ltop only ==> back to ltop + monitor. I have seen a similar problem with some recycled HP laptops and cycling through the display modes cures it.