WD22TB4 Will not charge a Precision 5540

Hi there,

We have had a Precision 5540 for a while now and a few months ago we purchased the WD22TB4 docking station to run 3 monitors. The monitors are running fine, however the docking station is not charging the laptop.

Occasionally the laptop will display plugged in and charging (it won't charge, the battery will eventually die) but most times even though the docking station is plugged in the laptop will show that it is running off of battery power and will eventually die.

We have replaced the docking station within the return policy thinking we just got a bad dock, and we have had Dell come onsite to replace the laptop's system board. 

None of these have solved the issue. When speaking with Dell they assure us that the docking station is compatible and should work...