What and where

Over the past 30 years or so I have accumulated a bunch of old computers which I am breaking down and attempting to refine to recover the various metals. I know that gold, silver, amercury are a few of the metals found in components as well as tin. Now the question is where exactly are the different metals found? OK some solders contain tin. Brass=copper alloyed with zinc. So what are the plated shields found around the external conections plated with? how do I identify all the various metals. Any help with this including links would be greatly appreciated. Most particularly I would like to know how mercury is recoved and where in components to find it, as this is probably the most toxic thing found in computers. I am aware that mercury can be separated from gold using a potatoe, but that method doesnt seem appropriate for removing it from computers.
Edit: I have noticed that most of the wires in computers (insulated, conected to power supply drives etc)are plated with what looks much like solder. Be nice to know what it is.

Hazardous Substances in e-Waste | ewasteguide.info

Material Composition | ewasteguide.info

http://ewasteguide.info/node/220

mostly what you'll be wanting to keep for the precious metals are boards and chips. Motherboard, CPU, RAM, add in cards(finger cards), hard drive and DVD boards, etc. The power supplies are mostly copper wires, possibly brass connector ends(maybe tin, not really anything I bother with either way) and have some small transformers and aluminum cooling fins inside, and is up to you whether to dismantle them, or take them in whole to the scrap yard, unless you can find a local buyer at better than tin/shred price because they're hardly worth shipping, you'll have to ask them there about that. Cases are merely tin/shred, and i leave plastic on them due to no local plastic recycler

In some instances older computers are best sold on ebay, either whole or parted out, as vintage

It seems from the questions that you are asking, that you have not even begun to do any research whatsoever. I suggest the gold refing Forum for some information on what is worth refining.

There is a lot of expense in setting up to refine gold properly and you can kill yourself in the process. Might I suggest that you take a look at some of the buyers in our buyer's section. Many people who really look into refining end up doing better by selling to our reputable buyers here. I am one that originally was looking to refine and am now an escrap buyer and seller. Just my 2 cents.

Please do not cite a you tube idiot using a potato to melt gold into a button. Not happening, no way,never work!! Please for all that is sacred and holy DO NOT mention using a potato for refining or recovering anything if you go to the gold refining forum.

And I have seen it mentioned a few times for the people just getting started refining, they will lose about 50 % of the gold during the process. So why not find you a toll refiner (someone who refines on percentages) or a ewaste buyer that will pay you for all your scrap.

That didn't take long ^
All the info you need is here do some history searches. GRF is also a great source to find specific metal compositions. Good luck and most of all Be Safe.