Topic: GridSeed 5-chip USB miner voltage mod - page 15. (Read 157001 times)

gbyg - When I check the .brd file in Allegro Viewer it looks like the two near E04M-330-16v are the same:

Reference Designator: C9
Package Symbol:       C1206
Component Class:      IC
Device Type:          C0805_C1206_10UF/16V
Value:              10uF/16v
Designator: F333

Reference Designator: C10
Package Symbol:       C1206
Component Class:      IC
Device Type:          C0805_C1206_10UF/16V
Value:              10uF/16v
Designator: F334

and the one over by K3-OCV-1500-2.5v is:

Reference Designator: C205
Package Symbol:       C1206
Component Class:      DISCRETE
Device Type:          CAP NP_C1206_DISCRETE_22UF
Value:              22uF
Designator: F206

C12 is that large capacitor labeled E04M-330-16v on the .brd file that you can download from Github.


If you haven't already, make sure to inspect around all the pins the Gridseed GC3355 chips.  The solder under the center one on mine oozed out when I messed up one pod testing it after a volt mod.
    

I am trying to identify the shorts in the pcb board , so far I found 3 capacitor might be short or faulty which is in yellow marked. i believe they are C9, C12 and C205. can somebody double check the value and the label for me please.

C9=10uf/16v
C12=220uf/25v
C205=22uF

3 of this capa looks same size, are they C1206 footprint?

if it's the one on the left of R52 (R139), you shouldn't need it, it's only used when switching the pod to different modes by software.
Just try the pod without it.
BTW, it should be R63, so 30k. you can replace it with your old R52(R139) that is 33k. The pod should work a little faster than 350Kh/s if you switch to this predefined mode.
the real R43 isn't connected anyway.

picture would have been better, but after checking the actual PCB, you are looking for R63, so 30K, or your old 33K or you can even leave it without the resistor, it should work

Does anyone know the Resistor value of the R43 resistor? Its two spots below R52...

I accidentally took it off of one of my gridseeds when removing R52. Its kind of burnt and probably not working so I will order another to replace it.

You're off....

technoese

your reply didn't sound like you knew this before.


edit :

just noticed that you have bold influenced by temperature
so you think that the given tolerance value will save the resistor from heart drift ?
nope tolerance means precision of the resistor value in production process. Variation of resistance with temperature is independent from tolerance.

Although a bit more expensive power bill wise, GPU's would be perfect for your 'space heating' needs
And they are becoming cheaper and cheaper now too, I believe.

if its hashing away and using 20w itll be producing 20w heat. hashing produces heat it doesnt turn it into another form of energy. ok there a small loss in the fan and the leds. but its all gone out as heat if not from the gridseed chips themselves then the voltage reg crystals and other pieces.

You could measure it putting it in a metre by metre box giving a 1m cubed volume area, of airt at room temp make sure only the grids are inside disconnect the fan and power it up and time how long its takes to rise the temperature in the box by 1 degree. take an ampage reading of just the grid seed, not the power convertor or from the wall or psu but at the grid. find the energy co efficient of air compare contrast and youll find your answer.
something like that anyway

You answered your own question....

How electrically efficient are these gridseed pods when used as a space heater?
I know they are not an "efficient" heater so I am not arguing for that use.  Please assume for this question that all other heat in the house is electric and that heat is required for 9 months of the year.  Also, please ignore purchase cost of the pods versus buying an actual heater.  This info could influence miners who live in cold climates when considering a voltage mod.

My guess is that 75% of the electricity used ends up as heat.  Do you think my guess is high or low or about right?  Probable less waste heat ratio at low wattage (stock LTC) compared to high wattage (dual mode).

well you have to measure and get the value you want from a pack of low precision resistors.
what you mean 5% drift?
each 47k 5% resistors will range between 45.x and 51.x when producing them, but its value is not going to be a variable value after that. each resistor will have a fixed value between 45.x and 50.x
A 48kohms 5% resistor measured by a DVM will remain 48k ohms unless influenced by temperature or other reasons. It should not be mistaken that the value varies randomly from 45k to 51k (5% difference)

Thanks sandor
Do you think it's possible to add an option to cpuminer to detect automatically the gridseed devices? Of course you will not be able to set per device freq with this option on but it would be useful to start the command in autotune without writing every single dev in the launcher string. I think looking at the dev ID do the job, Gridseed has always 0483:5740 as ID.

Use a fine tip...or better yet...a hot-air system is your best friend.

When I was modding my gridseeds, I accidentally removed one of the wrong ultra small resistors... I had to resolder it back in place, and it was absolutely ridiculous... I can't even believe I got it back on. An ant literally walked across my table at the same time as I was working on it, and the ant looked enourmous. the resistor was about the size of an ant's leg. I kept losing it over and over again from touching it and it would stick on my finger, or the tweezers, etc...
It is especially impressive I got it back on since usually when I take them off, it gets sucked inside of the ball of solder on the tip of my soldering iron... those resistors are way to small to make dumb mistakes guys I think I need a new soldering iron tip before I do any more.

Right. 30+W sounds ridiculous if not suspicious....
Yah, 48k 5% tol is close enough I recon as long as that 5% drift doesn't go the wrong way i.e. down below 45.6k which is useless for overclocking above 950 or 50.4k which is a tad too high but not harmful to other than power consumption hence profit.
I might get lazy on this batch and do the same thing though. It's mine (punn) anyway

i have used 48k resistors (measured and selected from a pack of 5% 47k 1/8W resistors) to mod my pods and they are running at 1200MH/s with almost zero hardware errors with a power consumption of 25w~ per each measured with a kilowatt meter. power supply is a 850 silver.
i don't know who got this readings but its not consuming 30+ watts.

Right, but keep in mind:
not all miners are the same hence your comparisons do not apply in general to all.
And, the watt/heat is not excessive w/49.9k. At least not with my pods.
I wonder what Gridseed has changed since the first mods were done on these things?
We know their quality control leaves quite a bit to be desired.
I'll be glad when I don't have to do diddly with my miners anymore. Just buy them, mine them, make them pay off ROI and profit from then on! BIG TIME! 

46.2K draw 1.43A  17.16W /MHZ 1160 /hash rate 490
 5W extra for 11k with the 47K!
watt is effectored by the resistor AND MHZ, so it good to put lower resistor and higher hash rate, as opposed to higher reisitor and lower hash rate.

Hey everyone, Just wanted to report back on my 10 miners from gaw,
2/10 did not work out of the box,

1 had clamped the fan wires and shorted everything out when I plugged it in. - Fixed this by repairing the fan wires
1 hashed, but nothing got accepted - fixed this by reflowing the solder with a heat gun... hashing like a champ now.

I modded 4 with the 49.9K resistor, and was running them averaged 1225mhz stable / average 507 khash and found the heat and power consumption excessive - 29ish watts when pods were hot.
I now have modded all to with a 47K resistor and total mhz average after tuning is 1190mhz / 501

47K vs 49.9K Comparison:

                       Hashrate Ave.        Watts            MHz (ave after chip tuning)        hash /Watt
47K                     501.65                20-22          1190                                              22.8
49.9K                   507.6                 28-29          1225                                              17.5


My definitive Thoughts
-Use a 47K resistor - the extra heat / power management is not worth the minimal hashrate increase.
-use sandor111's cpuminer
-No HW errors does not mean your miner is running optimally, some gridseeds will run slowly at clocks that are unstable, but not throw HW errors.
-use autotune for debugging and testing max frequencies of chips, but lock them in manually in your config script.