Laptop is Acer TravelMate 331T.
The name of this laptop port
connectorlaptopport
Related Solutions
It's a docking connector for the HP XB4 docking station and other expansion devices.
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Found in your Service manual at this page
Wild guess, magnets in the lid tell it when it's closed.
Placing another identical machine in line above will likely trigger the sensors in the same way.
Potential fix is stack each one the other way round, 180° horizontally, or just don't stack them.
Best Answer
It is the "Easy Link" Combo Drive port.
From the service manual "The EasyLink™ Combo Drive is a two-in-one floppy/CD-ROM or floppy /DVD-ROM “combo” drive that connects externally to the computer" Picture of drive is here: Acer EasyLink Drive
Good manual here Acer Service Manual