Is there a magnetic switch in laptops that cause no screen?

[robbins_charles]

Black screen after reassembly. Is there a magnetic switch controlling monitor?

 

[Lutfij]

Black screen after reassembling your laptop can mean a lot of things. Did you try powering up the laptop without the bottom cover on(prior to installing all the screws for the panel)?

Make and model of your laptop? SKU would help two fold.