trouble with external monitor

[Reid Mumford <reid@pha.jhu.edu>]

I have a sony vaio fx210.

I'm having trouble switching to the external monitor.  When i use the
fn-f7 key, my machine hangs.

I am running a custom 2.4.20 kernel.  I tried to compile sonypi as a
module but the module does not load properly.  I'm running a 4.2.1-6
Xserver

long ago, I had an 2.2.19pre17 kernel that worked just fine with the
external monitor without having to do anything.

anyone have any ideas?

Thanks.
reid