Here's a closeup of my Antminer.

http://imgur.com/SglhzeV

As I've understood the R66 transistor is where I should add pencil graphite (and there are 16 of these albeit with different numbers).

It has kind of two blank edges and the middle is matte dark gray. Does it matter where I apply the graphite?

What happens if I apply too much? Will only the HW error increase, or can the hardware get permanent damage?

What happens if I don't apply enough?

It should be applied when the miner is off, right? Should I do all 16 at the same time?

Is it necessary to use a voltmeter? Can the measure be made when the antminer is off? If I don't use the meter, is there another way to determine if the adequate amount of graphite has been applied?