Post
Topic
Board Mining (Altcoins)
Re: GridSeed 5-chip USB miner voltage mod
by
gbyg
on 17/05/2014, 21:36:28 UTC

Some of the specs on that part look excessive.  You'll want to match the specs as closely to this as possible: https://www.dropbox.com/s/w4m5vu4k5jgopk8/qm3022m6_ubiq.pdf

It's basically a 30v N-Channel mosfet with a 7mOhm RDSon and a 76A ID@25c (Continuous current drain at 25c).  You'll want to match the gate charge as close as possible as well.

I burnt out that same mosfet (3022m) and replaced it with the following: http://www.ti.com/product/CSD17552Q5A.  I blew my mosfet when curiosity got the best of me and I tried to dual mine with the voltmod at 1100Mhz.  Moral of the story...don't do that.  Don't even think of doing it.  I replaced my mosfet with the one from TI and it's back up and running but it's a little crippled.  Chip 3 seems to generate some errors no matter what speed, but it still hashes and I still get around 439khs from that gridseed.

I use 39AMP ID@25C mosfet just because i couldn't find more then 39AMP. there is few pin exposed on the bottom of the board. which was isolated by thermal pad. when i swap the pad with grease, those exposed shorted with the ground. and my 12 volt was off. nothing blew. so i think this mosfet start draining the current before any other part(like FB23/24) damage. which making me think that its better to use lower amp? i am not expert on this, what you think?