I have Toshiba Satellite A300 and external monitor doesn't work. When I connect external monitor computer recognise it, but no picture on it. Try all solutions about setup (in BIOS and with Display setup...).
I suspect on VGA driver or some kind passive protection components etc. varistors (it used with projector for presentations).

I have no any kind of schematics of that output VGA port.

Have you any idea?

Best regards, and sorry for my english (you can wrote me in russian, I am learning it on your forum .

А как реагирует функциональную кнопку переключения внешний-встроенный при подключенном внешнем мониторе ?

Есть какая-нибудь реакци на нажатие Fn+F5?

Thank's for fast reply,

yes that Fn+F5 not so perfect ("flickering"), but work's. With Ctrl+Alt+F12 I have done various setup but still the same, no picture on external monitor. I have done more test's, etc. on boot sequence nothing on ex.screen, also try with live Ubuntu, and some others bootable software and still nothing change.

I have uninstalled and deleted graphics driver, and installed new...
Didn't try to update bios because I think that is hardware problem.Not so shure???

But, right now I saw something new: in devices manger/display adapters/ second/ (on VGA output-port is external monitor connected) - I have "warning" that "this device is not working properly".
The problem code is 31, and more details is:
Error: Pnp problem code 0000001F.

And I have forgotten to say that in that notebook is Vista32, and graphics is Mobile Intel(R) 4 Series Express Chipset Family.

It is wide range problem "31" :"The device is not working properly because Windows cannot load the drivers required for this device".

I think there is comunnication hardware problem, or graphics adapter memory problem.

what's videochip in this laptop? tell exact part number and config of your unit(expecially, it is interesting, if this laptop has nvidia videochip).

Do you try to connect your laptop with normal monitor or LCD TV?

It has Intel AC82GL40/SLB95 (graphic/north bridge).

I try with external some CRT's monitors (2 different type), and with some LCD display connected to VGA port, but no picture on any of them.

I saw that it has problems when installing properthy graphics driver, sometimes "warnings", sometimes no errors after installation.

I think that there is problem bad soldering bumps on 82GL40.
I would be happy if I'm wrong.

And as usuall, in this job always problems with marking code on specific devices... Driver/buffer for this VGA output port is 8 pin. IC (U604 on this Toshiba A 300 m.board) marked as "C26".
It is 74AHCT2G126DP, datsheet is here http://www.nxp.com/acrobat_download/datasheets/74AHC_AHCT2G126_4.pdf

did you try to connect come other monitor? and the last one try: disconnect LCD-module from motherboard, and turn on the laptop. if you see the picture on external monitor - the problem is in drivers or some other software issues. and if you don't - this is hardware problem. and yes, this model(sat a300) has this problem(dying of northbridge).

This is few years old topic, but I see that I forgot to say that I have solved this problem with that buffer "C26" (U604), or 74AHCT2G126DP.
I have found it on some old Nokia mobile phone like 6150 etc...
Sorry for the late response.