So if I understand correctly you have boards from 12 PC's and the rest are from monitors and or TV's.
At this point you should not be concerned about chemicals, depopulating, or hot sand baths. You need to keep collecting boards and reading here on the SMF.
Look at the buyers and sellers thread here on the SMF.
Keep watching the videos but understand their knowledge is basic and limited and sometimes dangerous and ridiculous.
If you really want to learn about
ewaste keep reading here and learn to identify the boards you have.
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