Laptop Power Jack Repair

I have been doing the powerjack repair on laptops for a couple of years now and usually without a hitch and now i have another. "2 boards"

I need a little help to get my head round this problem:
I have two motherboards DV4000 with the same problem.
The battery wont charge unless an external monitor is plugged in.
Both powerpacks and powerjacks are fine.
It has been reported to me that both laptops have been dropped.
other than the charging problem both machines work fine.

If anyone in the UK needs a powerjack repair or want to do it themselves
visit my website for tips. www.powerjackrepair.com