Not possible because the power supply , front panel board, thermal sensor, and and and is not the same. The 620 has IDE optical drives and a floppy controller. The 780 has neither.
Dell's are custom and proprietary from one model to another. Even the rear motherboard I/O panel is different.
In practically every case its not possible to interchange motherboards, front panels, etc.
Dell forum member since 2002
Dell Inspiron 15 - 5577 Laptop
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