Post
Topic
Board Hardware
Re: [ANN] US/North American Bitfury sales now open ***full prototype pics***
by
buzzdave
on 25/10/2013, 07:23:56 UTC
We are a couple days yet from getting our 16 chip boards with the trimmer on the board.  I have some 8 chip boards that are an experimental OC board that use the same trim pot and I want to set the stage for how this will work.

In order to use this trimmer, you *must* have a multimeter and know how to measure resistance.  If you don't know what I'm talking about, you aren't ready to try to OC your boards.

An easy place to take resistance measurements is to get ground off the M-board GND terminal (where you would connect direct 12V cables - the terminal screws).  The red probe would go on the top metal contact of the Pulse inductor, which is the large bulky component on the H-card.  Be sure not to also touch the caps that are nearby or you won't get a correct voltage.

While measuring the voltage, use your super-micro tweaker phillips screwdriver to *slowly* turn the trimmer clockwise for higher voltage or counter-clockwise for lower.  The trimmer has an effective range of about 180-degrees.  If you turn it down too far, you will see voltage begin to rise again. 

Don't make voltage changes quickly.  If you go higher than about .895v you better know what you are doing or you will kill your chips.  I don't even know what voltages people are getting away with on these boards.  Find a guide or post before you start mucking around.  Overclocking *will* reduce the reliability of the boards.