help on debian on Thinkpad R31

[Mao Xiaoan <xiaoanm@gmail.com>]

Hi All,

I am new to Linux. Yesterday, I installed Debian 6.0.1a on my Thinkpad
R31 (2656 J2C). It was installed successfully, but in the end when it
rebooted, the laptop monitor doesn't show anything (it is grey),
although it is still working fine if I boot it to windows. I connected
a stand-alone monitor to the laptop via VGA output, and switch to it
by Fn+F7, there is display (1280 x 1024, 75Hz). The laptop monitor
itself support display up to 1024 x 768, 60Hz.

I don't know what could be wrong, so I don't know what more
information should I provide to help identify the problem.

Can anybody help please?

Many thanks
Shaun Mao