just like the commercial
salvages parts $1.87
internet connection $87/month
engineering review - priceless !
for most of the parts, there are printed numbers and letters
put them in google, see what comes back.
the more often you do that, the better you get at it.
the problem is using what you have.
if you want to get a lot of parts, get a circuit board from an alarm company. they toss the old stuff out.
use a hot air gun or blow torch
put a layer of aluminum foil out
and a brick
heat the board until some of the solder melts.
with the LEAD SIDE DOWN, wack the board on the brick.
the wet solder flies off onto the aluminum and the other parts fly all over the place, free of most of the solder.
WEAR EYE PROTECTION AND GLOVES !!!!!!
HOT LEAD FLYING AROUND !!!!!!!!