GRIDSEED G-BLADE Overclocking 7Mh/s, improvements and repair

[natbyte]

You can use a normal iron, for the capacitor and resistor changes, I just used a fine tipped 40 watt soldering iron, however for changing a mosfet you will need a hot air setup.

[Blisk]

I will just cut off the mosfets it is much easier and than throw it away.

[DarkKnight]

You still need to reattach them with something. You can't solder the pad underneath with a pencil, I think. I was looking at my blade today, and that damned resistor is so tiny.

The last SMD IC I tried to replace (not mining related) was a damned disaster. I ended up using a razor blade to carve the solder out between the pins because they kept bridging.

I was thinking about the power jack problem, 8 pin EPS connectors are (unoffically) rated to >300w. An extension cable would provide the connectors needed, and one would only need to cut it in half and creatively solder the pig tail to the board properly. I don't suppose it would be pretty, but GC should really have equipped the board with it in the first place. That should comfortably supply 12.5A to each blade. PCIe would also work, but should really connected observing the ATX spec (3 +12v, 5 GND), in case someone actually plugs a PCIe cable into it to power it, and that's rated to 150w. Using either would stop the melting power connectors, I suspect.

[Blisk]

It is more problem to get chips off than on.
When you solder you need a sharp point on and using magnifier, it is hard to do, but with some experiences it is not that hard.
If you never did that than it is not for you.

[styson]

Lost them while busy trying to find a short on the board, 3 Ferrites were blown and the FET is shorted !!! Waiting for replacement FET's now.

Thanks J4bberwock

anything else than the ferrites and fet blown?

it can be helpful for some other people.

As far as I can see, nothing else damaged, I did get a confirmation from gridseed that you can use 100ohm 1206 100Mhz Ferrite Bead instead of the 300ohm 1206 100Mhz bye the power plug, but they say you can't go lower than that, but I suppose if your using a good quality power supply you can just put a 0ohm resistor in the or jumper it like you guys do.

As for the FETs, I have ordered :

CSD16321Q5C (replaces IRFH5302) * Dual Cool
CSD17556Q5B (replaces IRFH5300) * Correction these are not DualCool

Which are the DualCool type, should run a lot cooler  

Sorry guys, just made a correction on the above post, the CSD17556 is not DualCool.

Got the CSD16321Q5C on 1 blade so far, much cooler, finger does not burn now when I touch it

Will Change the CSD17556Q5B's this week and then to do the resistor mod.

If I increase the resistor by say 3K, what will the heat be like on the gc3355's are heatsinks needed ?

Wish I had my cnc milling machine up an running, would have converted the whole blade to water cooling.

[Blisk]

you won't get that much more out of blade when water cooling. You will use much more electricity

[powersup]

I just wanted to say what a great job you are all doing.  I have recently received a blade and plan to volt mod.

I do have a couple of questions which i hope someone can answer.

1. Can I simply bridge across FB23,24,25,27,28, and 29 and leave the ferrite beads in place?

2. what would be the max resistor value you would recommend if I don't replace the 220uF/16V cap, but instead add a heat-sink and actively cool it.

Thanks in advance.

[styson]

After putting in the CSD16321Q5C the stock 220uf gets very hot, just a warning to others, you might want to put a 20v or 35v cap in its place.

[Blisk]

Did anyone meassure ferrites which needs to be replaced?
Have anyone data?

Impedance:?
DC Resistance Max:?
DC Current Rating:?

[styson]

Did anyone meassure ferrites which needs to be replaced?
Have anyone data?

Impedance:?
DC Resistance Max:?
DC Current Rating:?

The 1206 size Ferrites are 300 Ohm 100Mhz 3A, the 0805's are 300 Ohm 100Mhz 1.5A

You can just use 0 Ohm resistors in their place or bridge it with 2-3mm thick of solder.

I replaced mine with 120 Ohm instead of the 300 Ohm and no problems.

[DarkKnight]

It is more problem to get chips off than on.
When you solder you need a sharp point on and using magnifier, it is hard to do, but with some experiences it is not that hard.
If you never did that than it is not for you.

I've had a soldering iron in my hand since before I was of a reasonable age to be using one. That said, I grew up working on electronics long before SMD were available, let alone mainstream. Back then, when you bought a 'computer' it was more like buying an unassembled arduino kit now. You built the whole thing, soldering your components by hand, then wrote your own programs in assembly or copied it out of some magazine.

My point is, I have plenty of experience working on circuit boards, just not with SMD components. I'm quite sure it isn't beyond me. The time I was speaking about with the SMD I was working on was a decade or more ago. Back then I couldn't have purchased new solder tips, let alone a rework station even if I had known they existed. Most jobs, including this one are tremendously easier with the proper tools -- and less caffeine.

You can just use 0 Ohm resistors in their place or bridge it with 2-3mm thick of solder.

You might consider adding a ferrite core on the supply wires if you opt with using resistors on the board. Just bridging with solder could add a considerable amount of inductance, and causing EM noise problems down the road, and I believe that to be a bad idea. This may not present as a failed blade, and may instead just limit your ability to ramp up the proc frequency because of HW errors due to unstable supply.

[Blisk]

There was reported some troubles bridging ferrites so I think I will put more powerfull one

[racebyu]

There was reported some troubles bridging ferrites so I think I will put more powerfull one

I soldered some wire across where the old ferrites where located and no issues so far.
Just waiting for the smaller heat sink for the FET's to add before adjusting the 10 turn
50k pot up a bit. Have a thermal epoxied heat sink on the back of the board also and
added a 220uF 35vdc capacitor and raised it up off the board with its tabs for better
cooling.

What was the issue with bridging the old ferrite locations?

[gridsad]

You might consider adding a ferrite core on the supply wires if you opt with using resistors on the board. Just bridging with solder could add a considerable amount of inductance, and causing EM noise problems down the road, and I believe that to be a bad idea. This may not present as a failed blade, and may instead just limit your ability to ramp up the proc frequency because of HW errors due to unstable supply.

Not to disagree at all, though familiar with ferrite cores had not even heard of ferrite beads before modifying the 5 chip miners, but will just point out that some of the later blades did ship with 0 ohm resistors in place of the anal beads.

[Blisk]

I assume that ferrites are there because of high current and when connect it it gets a big current shock which is dumped by those ferrites, 0 ohm resistors can replace that.
But I think there are not 0 ohms but in real some 0,5 or 0,3 ohm

[BAUAR]

Hello all,

One of my gridseed blade failes.

I fitted the following a 35v 220uf capacitor, 43k ohm resistor. I put three fans on all sides. Blade very shining.
Power cables began to melt

Can anyone provide me with the schematics so i can repair it?

Thanks!

Hi,
there are no real schematics.
I'm using the 8 chip ones from gridseed github.
https://github.com/gridseed/gc3355-doc

43k resistor is only if you are crazy like me and if you are confident you can fix anything that will break or lose your money
39k is a safe one.

only one extra fan is needed to blow from one side of the powerboard.
plus dissipators under the PCB where the mosfets are, and on the mosfets, you can even add some to the inductance/coil/choke

Your cable started to melt because the wires inside are too thin.
You are asking for 150 watt / 12 amps on each PCB.
I'm using 0.75mm² wires with a screw terminal instead of the original 12v plug connector on the blade.
http://itp.nyu.edu/physcomp/uploads/screw_terminals.jpg

solder it under the PCB, not on the same side there was the 12v plug. It will be easier to screw/unscrew.
The solder point near the ferrites is the positive
The solder point nearest from the edge of the PCB is negative.

I did a detailed diagnosis of my device. All power resistors are healthy.
The chip that manages power is probably blown.
It is: UP1509P
Please tell me the site where can I buy this chip and it is guaranteed quality.

Thank you in advance.
Trifon

[Blisk]

you can find it at farnell or reichelt

[DarkKnight]

Not to disagree at all, though familiar with ferrite cores had not even heard of ferrite beads before modifying the 5 chip miners, but will just point out that some of the later blades did ship with 0 ohm resistors in place of the anal ferrite beads.

Everything is fine until it's not. The factory need only keep it working for as long as the warranty period lasts.

I assume that ferrites are there because of high current and when connect it it gets a big current shock which is dumped by those ferrites, 0 ohm resistors can replace that.
But I think there are not 0 ohms but in real some 0,5 or 0,3 ohm

That is one of their functions, yes. Switching pools, temporary disconnections, even coin switches might cause current surges. Eventually, that is going to kill some parts. With the incredibly rapid pace of profitability, I imagine these will need to be running a long time to make back their cost. That is a consideration for me, anyway.

[BAUAR]

Hello all,

One of my gridseed blade failes.

I fitted the following a 35v 220uf capacitor, 43k ohm resistor. I put three fans on all sides. Blade very shining.
Power cables began to melt

Can anyone provide me with the schematics so i can repair it?

Thanks!

Hi,
there are no real schematics.
I'm using the 8 chip ones from gridseed github.
https://github.com/gridseed/gc3355-doc

43k resistor is only if you are crazy like me and if you are confident you can fix anything that will break or lose your money
39k is a safe one.

only one extra fan is needed to blow from one side of the powerboard.
plus dissipators under the PCB where the mosfets are, and on the mosfets, you can even add some to the inductance/coil/choke

Your cable started to melt because the wires inside are too thin.
You are asking for 150 watt / 12 amps on each PCB.
I'm using 0.75mm² wires with a screw terminal instead of the original 12v plug connector on the blade.
http://itp.nyu.edu/physcomp/uploads/screw_terminals.jpg

solder it under the PCB, not on the same side there was the 12v plug. It will be easier to screw/unscrew.
The solder point near the ferrites is the positive
The solder point nearest from the edge of the PCB is negative.

I did a detailed diagnosis of my device. All power resistors are healthy.
The chip that manages power is probably blown.
It is: UP1509P
Please tell me the site where can I buy this chip and it is guaranteed quality.

Thank you in advance.
Trifon

you can find it at farnell or reichelt

He's not there this controller.
Any other ideas?
hire: http://www.oemstrade.com/search/UP1509P/

[Blisk]

Try to find replacaing chip for this one.
Here is datasheet.
http://filesave.me/file/39234/uP1509-DS-F0000-pdf.html