serial mode on ipaq 1940

[yourmate]

hello,

could anybody tell me how to activate serial/USB mode on iPAQ 1940?
I've tried several combinations, but neither worked.
I've found it on a 2210 easily: Contact(2)+iTask(4)+Power(5) buttons pressed and reset with the pen...

any idea?

cheers,

ym

[yourmate]

so many are watching, but none knows :(

[yourmate]

getting more & more desperate...

[yourmate]

I give it up:(