Diagnosing a MacBook that decided to stop powering. (A1342)
The symptoms are not good. The first thing to check on MagSafe issues is to replace that sub assembly since it’s cheap and easy. If you are not able to source that part, you could disconnect the battery and the display to see if you can get the mac to boot as a minimal system (or at least the MagSafe light to work).

Hopefully you don’t need a new logic board, but by disconnecting things that aren’t critical, you should be able to build up a working system assuming each part works.


https://support.apple.com/en-us/HT201624


For any Mac that’s not vintage, Consider a flat rate repair at Apple for situations like this. Assuming the internals aren’t mangled badly, they can and will test each part and repair all (including reasonable number of missing screws) for the paid flat rate cost.

Since this is vintage, your best bet is sourcing some cheap donor machines in hopes of getting enough spare parts to validate which item has failed here.