Quote from: shaninium on November 01, 2017, 09:34:31 PM

Quote from: blissz on November 01, 2017, 09:27:52 PM

https://preview.ibb.co/jmOdDG/20171031_171454.jpg

The antminer D3
As an owner of the October batch of the antminer D3 I have good news. I now run my antminer D3 stable @ 15Gh/s with just 750 watts. Cool

I decided to go for a mod, because I couldn't run the fans at full speed because of the noise. Therefore I could only run 13 Mh/s @ 850 watts before the mod, which is now not very profitable. Cry

The mod:
To get there I tried to reverse engineer the power circuit of the antminer D3 mining boards. Unfortunately there is some chip which I still don't know the specs from (labeled ADP BDY+), but I found out it's controlling the PWM of the mosfets.
So I tried changing the resistors around it and found out that changing the resistor R80 controls the voltage. Woop Woop Grin

So if you want to do the mod I advice to replace R80 by a 25k ohm potentiometer. The voltage can be measured over C948

Improvement:
without the mod the total voltage supplied to the asic chips is fixed @ 8.15v on the October batch. That means 1300 watts for 19Gh/s
After the mod the voltage is fully adjustable by using the potentiometer. It also allows to increase the voltage for overclocking if you want to do so.
But overclocking is not my goal, I wanted a silent miner: Therefore I now run my boards @ 7.1v @ 430 Mhz stable. That means 750 Watts for 15Gh/s
That is 50 instead of 68 watt per Gh/s Cool

Photos
The mod is quite easy if you have some proper soldering skills, but it's tricky if you don't have the proper tools / not have a steady hand...

https://preview.ibb.co/cYmyDG/20171031_163632.jpg
upload gifs online

ps. I will make new higher res zoomed pics soon.

Other possible mods:

Fan mod: (only when undervolting)
as I don't like that noise at all I also did some fan mods. I added a voltage regulator on one of the fans to decrease the noise during startup. cgminer won't allow you to go bellow 5000rpm othwerwise the miner fails to start.
Furthermore I replaced the second fan with a 2000rpm silent fan. To make this work you have to use the yellow wire (fan rpm) from the first fan as wire for the 2nd fan. Otherwise it detects a too low fan speed on the second fan.
I can say that running both fans @ 2000 rpm is acceptable to run it in a living room now.

Power supply mod: (only when undervolting)
By default the power supply runs @ 12.2v. I used the potentiometer inside to make it run @ 12.05v. This saves a few watts of power as well. Furthermore I added a regulator on the fan, to run it at 5v as this small fans makes an annoying high frequency noise when running at full speed.

Support
I hope this information does inspire you and help you improve the efficiency on the antminer D3. I hope to improve the mod: as I want to look into a software mod to enable changing the voltage from software. This would really open up the possibilities for all the users.
To get there I still look for a copy of the November miner firmware as bitmain is not supplying this yet. If one can login using ssh and make a full copy of the all the files that would be really welcome.

Support on this mod project is more than welcome as I want to have a spare D3 for modding the software. A (damaged) donor D3 or S9 would be very welcome as well, as this baby really needs some mods too

DASH: XpppzJw4PJyTYYEJNf78Zt1DrHVAA7ogvx
BTC: 1Na1A2pBSWn6ZEw3mSG9NLpQY77brWcfue

Impressive, well done. Undervolting would void the warranty prob like with oc.

Which is the first FAN ? inlet or outlet fan. ?
What Fan model are you using that gives you 2000rpm silent fan ?
Can't it work if i replaced both fans with the silent fans ?