ATI Mobility Radeon HD 5470 and two monitors - can see only one after

Not possible.

Mobile video card can only output to one external monitor. Radeon's EyeFinity would be needed for a 3 monitor setup (including the laptop's display). Eyefinity requires the use of DisplayPort. I don't know of any laptops with DisplayPort other than possibly Apple laptops. Due to that lack, I would assume there are no mobile Radeon video chips/cards that features EyeFinity.

It's not clear from your post if you're trying to just use the two external monitors, of if you're trying to use all 3 (including the laptop's display)...

Assuming you're just trying the two externals, and disabling the laptop display...
I do the same with my 1st gen i5 laptop with Intel's HD integrated video -- one monitor via VGA (1280x1024), a second via HDMI (1600x1200), and it works fine, as long as I keep the laptop monitor turned off (I just keep the laptop closed, and use a bluetooth keyboard and mouse).

I don't have any problem between re-boots -- perhaps there's an unfortunate difference between the ATI & Intel video drivers that's hosing things up for you.

thanks guys, I`d like to use the two external monitors setup only. I keep the laptop lid closed so the laptop display is shut down, except for the very short time during the startup process, when I need to open it to press the start button (Dell Inspiron doesn`t have docking station.

When I start the laptop with VGA cable manually disconnected, the HDMI monitor works well. When I start the laptop with both HDMI and VGA cables connected, only VGA monitor works, HDMI monitor is blind.

Any advise please? Could it be that the short time I open the laptop display to press the button is causing that external monitors are not working simultaneously?

Like I stated, not possible. You can only use one external monitor with your laptop.

You might want to consider going with the Matrox DualHead2Go

-Wolf sends

guys, I can confirm that it does work (both external monitors are live), but only if I follow this routine - turn laptop off, disconnect the VGA monitor cable, turn laptop on, and when the monitor connected via HDMI turns on, I plug again the VGA cable from the second monitor and voila - both monitors are up and ready nicely

but if I keep both HDMI and VGA cables connected, shut down my laptop, next time when I turn laptop on again, only one monitor (VGA connected) is working, the second (HDMI) is blind

basically I can work with both monitors if I use the process described above while allways when starting the computer, but I want to avoid it, as my laptop is hidden under my working desk, so its quite complicated always to disconnect and connect again the cables

any ideas please?

thanks very much

Sorry, to burst your bubble of knowledge there but you're completely wrong. See ASUS B Series laptops that support Eyefinity WITH DisplayPorts.

In other words, YES, you can run 3 monitors assuming you have a compatible laptop such as ASUS B Series. I'm sure there are other manufacturers that support multi-displays, you just have to find them. Good luck!

AMD Eyefinity technology is supported by graphics cards in the ATI Radeon™ HD 5400 series and higher. These cards can support up to six monitors (depending on the model), subject to the following restrictions:
• A maximum of 2 legacy monitors (VGA, DVI or HDMI) can be enabled simultaneously, provided that each monitor is connected either directly or via a “passive” DisplayPort™ adapter/dongle. “Passive” adapters/dongles will NOT support more than 2 legacy monitors.
• To enable support for more than 2 monitors, “active” DisplayPort™ adapters/dongles are required (or monitors with direct DisplayPort™ connectivity must be used).
• Approved “active” adapters have no general connectivity restrictions with AMD Eyefinity technology.