Topic: GridSeed 5-chip USB miner voltage mod - page 60. (Read 156988 times)

Sure you can...but is more complicated...Keep it simple and easy...but effective...

Regarding Wolfe2014, I reviewed his comments and I think that in this business (especially HR) things can get fuzzy quickly. You will always achive variable results depending on many things outside the control of the mods themselvs. There is no 100% guarentee in anything these days, least of all mining...
Almost every pool even sais that their HR isn't a clear indication of performance, only submitted shares count for anything.

That said, I feel comfortable enough to have him mod 10 of my GSDs so I can compare side-by-side at my location and using my pools.
I should be able to report back in a week on the results I am seeing, both at the GSD level as well as the pool-side return.
Other than reading what he has posted, I don't have any affiliation with Wolfe2014, so I hope you will consider me as reasonably independent.
Ill run both modded and un-modded GSD's side-by-side as different workers and compare the results (shares) at the same pool.

Exactly...Right on...Thank you for the picture, buddy...!

DO NOT MAKE THIS MODIFICATION! It may burn out your fan or worse, brick your pod!

Keeping the fan running at a lower speed cools and keeps the GS5 at room temperature while overclocked/over-volted for increased hashing performance. I have 6 of them running this way off of 5V USB power and they are just fine! And ELECTRICALLY SOUND and CORRECTLY powered!

IF you absolutely must run your fan at a reduced speed/rate/cfm, use a Voltage Regulator Made To Do The Job between 12V and your fan.
There are plenty of them available on the net. An LM7806 6V regulator, with a 100nf cap connected between input and ground and output and ground, soldered together and wired according to its PDF datasheet.
Insulate as needed.

The regulator will not get hot, not hardly even warm except for the power it dissipates from dropping 12V, actually 13.8V to 14.2V DC to 6V DC.

There are also mini DC voltage regulators sold on eBay that wire in between the 12V +/- rail and the fan so you can manually adjust it's speed or automate it via temperature sensing.
You can search for it on eBay using '12v dc fan speed regulator'
They cost a few bucks.
Anyway, DO NOT make the suggested modification per this diagram in the picture!
It could ruin your fan, cause erratic operation, voltage fluctuations or worse, brick your pod!

Making any modification to your pod is strictly at your own risk and responsibility.

If you want a qualified technician to make your modifications for you, PM me and I will be happy to assist you in doing so!
 

Personal preference, is what comes to mind. Tinkering is the other thought.
Someone just had to find a different method / solution to a problem that has already been solved.
Their solution is actually 'in reality' not a solution, but another PROBLEM! And potentially hazardous to the pods health! It could blow the whole smash and brick your pod!

There is little to no additional demand being put on the USB power supply end. .078 'Milli' Amps is NOTHING!
Yes, it adds up but still, even with 10 GS5's it's only 780mA, with 20 it's 1.56A which is nothing for a USB power supply, supplying 2.5A to 5A to the USB hub etc. Being fed 5V from the rail of a PC psu is even more robust power wise.

There is no noise on the fan line that can disturb or harm the USB drive circuit and definitely ZERO noise or EMI of any kind interfering with USB data operations either.
There is enough CFM of air being pumped by the fan at 5V to keep the pod cool enough while running in Scrypt only mode.

It is common knowledge as well as recommended by and instituted by the manufacturer that every USB hub should be powered by at least a 2.5A to 5A power supply due to all the pods it's powering in the first place. There is TONS of headroom for the addition of .078mA per pod, if properly powered in the first place.
USB power is MADE to do what it is doing by supplying 5V to the fan.

One other important observation is, the connections made via the 12V rail and the voltage regulator is what's called a floating ground or feedback LOOP which is why the power fluctuates as per your voltage measurements of "6.69V...11.82V - 5.13V" ...? This variance is an indication of improper and unstable power supply from the voltage regulator and most likely being caused by other electronics pulling power from it such as the processor chips themselves! DANGEROUS! BAD IDEA! DO NOT TRY IT! It's actually causing the fan to try to close the loop in its quest to find GROUND or +
The pretty quiet little fan is now in danger of making magic black smoke and bricking your pod!
DO NOT CONNECT POWER TO THE FAN THIS WAY THROUGH THE VOLTAGE REGULATOR!
It's not actually connected to a 'real' - ground source. It's floating and that is dangerous in itself and could harm the electronics of the pod if the fan goes bad or there is a short.
It's not a valid solution electrically speaking the way it is powered on the 12V rail side using the Voltage Regulator as a floating ground connection. That is not what it's made to do.

The USB power solution IS VALID because it's made to supply power to small DC motors as well as electronic driver circuits, such as it is! The air flow supplied by the fan via 5V USB power us perfectly fine and sufficient to do what ever little bit of cooling it has to do!

Please, just leave well enough alone! Words like "if it ain't broken, don't fix it" comes FIRMLY to mind!
How confident am I of the 5V USB solution? 100%!
And if powering your pod's fan via my 5V USB power mod bricks your pod or burns out your fan, I'LL BUY IT! Just make sure you use a good power supply to feed all those pods their USB juice in the first place.
It's required with or without the fan mod anyway.
But if you brick or break it while making the mod, it's $ALL$ on you!

Or you could just cut the wires and put them on 5V from an PC ATX PSU right?

@ZiG

You mean something like this? :
http://i.imgur.com/t5Rp2tC.jpg?1

Speaking of Fan mod...for silent operation...:

With all my due respect to Wolfey's solution...There is another "Classic Silent fan" solution from the CPU overclocking experience...7V fan driving...between 12V and 5V power lines...

How...: Disconnect the GROUND/BLACK wire from the original position...and solder back to the 5V regulator uP1707 output...this is the small / medium size 8-pin chip to the left of the 12V PS supply connector...the easiest point to connect are to the big output SMD caps to the right of the IC...C201/C203...their pins towards the center of the board...facing the square inductor close to them...this is 5V output supply...uP1707 is rated for up to 3A...so the current load of the fan should not have any effect on the circuit...

Mine is running whisper quiet @ 6.69V...11.82V - 5.13V ...

IMHO this is better solution ...because of the higher voltage...better performance/cooling...but still silent/no noise...not creating ANY load to 5V USB supply, preventing possible issues with USB hub(s) with many Gridseeds...not having enough juice...etc...

As usual...try at your own risk...

Cheers,

ZiG  


P.S. I am assuming that everybody, interested in these mods, has already PDF schematics of the 5-chip Gridseed device from...:  https://github.com/gridseed/usb-miner/tree/master/hardware

READ!!!!!
page 5, 6, 12, 14 and so on. It's all written up and described!

Hi, Im looking for some one in Wi to perform some of these modifications. Please Pm me. sorry wolfey2014 but shipping the units to you i don't think would be cost efficient but please send me a pm if you wish to discuss.

Can someone post details/pictures of the 5v fan mod? Is there another point to solder the fan leads to? Is it dangerous in any way (dangerous in terms of load to the newly utilized power circuit)?

Here are some figures I came up with while load testing my modded pods.

49.9k mod
690mA idle
1390mA 1125MHz 19.18W + 3.90W 5V Fan = 22.94W 503KHs to 671KHs 
1410mA 1150MHz 19.32W + 3.90W 5V Fan = 23.22W
1420mA 1163MHz 19.59W + 3.90W 5V Fan = 23.49W
1460mA 1200MHz 20.14W + 3.90W 5V Fan = 24.04W
1480mA 1225MHz 20.42W + 3.90W 5V Fan = 24.32W 503KHs to 721KHs
These figures do not include power supply current suckage.

One other thing I noticed. These things won't quit sucking power after quitting the mining program. They just keep sucking the same level of current as if they were actually mining.
They have to be hard reset by re-powering the 12V rail. At least in cpuminer they have to be.
Has anyone else noticed this running cgminer or bfgminer?
I looked at all the minerd commands that are available but none of them cause a power cycle or reset.
That sucks! 

What's the new default wattage after the mod?

Ok I see, it seems actually much more easy like this, having more space between the points, more space to use the solder iron

It's the test point that is connected to the rear (not inner) most solder point of the SMD chip.
It's easier to solder it there than otherwise although I can easily do it that way too.
It's optional, if you must use the original solder points. Electrically, they are the same connection.

so you did not solder between the two connection points of the SMD that you replaced.

what's that other point you took to solder the resistor on?

is there another connection point for r52 resistor. cant solder to that point closer to outside, so, is there some other connection point for it?

Well I saw that they also did the the test on : http://cryptomining-blog.com/1839-another-new-voltmod-update-for-the-gridseed-5-chip-btcltc-asic-miners/

and they also show 20w

it aint that important. 56k at 1% gives a 560 tolerence cool 56k +- 560 ohms not bad for a price.
56k at 5% gives a 2.8k tolerance. ie 56k +- 2.8k ok not as good but it depends on how tight you want yor voltage to be, plus you can always check it before using it. then stress it A BIT and check it again see the resistance falls within your range. yes 1% is better but its not crictal. plus 5% at certain ranges are a lot easier to get hold off, price difference is nothing, they can be harder to find that all. And seriuosly you think theese things made in china was all produced using 1% resistors? you really believe that looking at the build quality? exactly.

if you can gt hold of 5% use it just bear in mind the tolerence. 56k might be pushing the limits of it that extra 2.8k could break thoose limits. just be aware of the parts your using and there limits and tolerance!!!
and lower values it obviuos less ie 10k would be +- 500 ohms!

you power usage seem to be WAY off or are we talking mulitpe grid here?

ive just tested my grid - pre mod - running at 850mhz, and it showed a draw of 0.6A.
so
Watts = V . A
         12 * 0.6
    = 7.2 Watts - pretty close to the 7w spec given by gridseed. oh that with the stock 33k ohm resistor - NOT 12.4 wat.

i really dont see increase the resistor to 56k producing a 44w draw per unit. thats a heck of a jump for a few milli volts. whats the voltage increased to 1.28? 1.3v?

So please check your calcs check your measure and report on single unit etc.
(mine was take using digital mulitmeter set in series to my grid - consume modified molex adaptor just for measuring the amps with my meter)

And anyone still using the orignal power supply that came with it BIN IT!!!!!! i came home the other day and my flat was without power fusebox tripped. turned out the gridseed power supply origanl had tripped the fuse. everything now runs off an old computer PSU.