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

[Sir William]

This is a scrypt miner, not an sha256 miner.  It will mine Litecoin and variants, not Bitcoin.

[manotroll]

This is a scrypt miner, not an sha256 miner.  It will mine Litecoin and variants, not Bitcoin.

ok
That 7mh / s per plate?

[Sir William]

No, 3.5 per plate, 7.0 total.  Put another way, about 40% above stock.

[manotroll]

No, 3.5 per plate, 7.0 total.  Put another way, about 40% above stock.

ok

[Shermand100]

Hi all, I know this is really a bit of a dead topic but this may be useful for hobbyists still?

So I got one of these units as I got interested in the crypto scene about a year ago with a couple of antminer s3 on the cheep. All was well for about a year until one of the blades started getting too hot, it smelt hot, like a burning. Anyway of all the components the choke seemed the hottest and had dulled in colour along with an area of the pcb around it. Thanks to this thread I've got it going again. It however took quite a few hours of trawling to get all the info I needed. A bulk of the info was on page 21 and 22 of this thread and couldn't have done it without that. So thanks to @J4bberwock for the fault diagnosing voltages and the components lists.

So I've used those and a new choke, I'll list them below along with the store I bought them from, as again, it took a while of trawling to find a store that had all the bits to only pay delivery once. As these are old I assume repair could be on a few peoples minds, hope this helps someone.

I'm in the UK so all in £

Upper gate http://uk.farnell.com/texas-instruments/csd16321q5c/mosfet-n-ch-25v-31a-8son/dp/1791476 £1.42

Lower gate http://uk.farnell.com/texas-instruments/csd17556q5b/mosfet-n-ch-30v-100a-vson-8/dp/2501093 £1.89

Choke http://uk.farnell.com/coiltronics/dr127-1r0-r/inductor-smd-1uh-15-5a/dp/2075607 £1.84

Capacitor http://uk.farnell.com/kemet/a767mu227m1vlae028/cap-alu-polymer-220uf-35v-rad/dp/2614188 £1.63

So with the 2x upper and 2x lower, choke and capacitor replaced, all in £10.03 for parts. I went for the repair to teach myself smd soldering and to get a bit more knowledge on these low voltage and high current circuits which seem to be used in all miners.

And the final assembly...quite pleased with myself...

[Mister_Fix]

One of my blades started spitting out thousands of hardware errors per second at the stock 600 MHz clock so i did the usual test points to see if there was a fault on the board (https://bitcointalk.org/index.php?topic=576784.msg7330855#msg7330855) and there was not fault, everything was fine, i don't get it, why did the board suddenly start having so many hardware errors, does anyone have an idea of what's going on?

[Fenboy]

Hi, recently setup my G Blade again as I had the opportunity of free electric.

Was running fine for a week and then stopped accepting work (still showing hashrate though). When I checked on the unit, the power brick had failed on the board powering the fan, so boards probably overheated.

Is anyone able to check and repair my boards? I'm in the UK.

Thanks

[Shermand100]

Hi, recently setup my G Blade again as I had the opportunity of free electric.

Was running fine for a week and then stopped accepting work (still showing hashrate though). When I checked on the unit, the power brick had failed on the board powering the fan, so boards probably overheated.

Is anyone able to check and repair my boards? I'm in the UK.

Thanks

On page 22 of this thread there is a great couple of pics of fault diagnosis by j4bberwock. If you've read a bit of this thread you'll get that the most common failure of these boards is the mosfets in the top right of those pics I mentioned overheating.

If you can prod about with a multimeter yourself and establish for sure if it is the mosfets then you can source the parts in my post (2 up) and either fix it yourself or take it to a proper electronics repair guy and they should have it done in few minutes. There's a chance it may not be the mosfets though and it still won't work.

I did mine myself and took that chance.

When I repaired mine, I also bought from china a new hashing board in case I wasn't able to repair my first. I managed to get it for £15 with free shipping to UK. My parts for repair came to just over £10. So I'm not sure if it was really worth it apart from the experience.

For some reason, checking again the price of the boards has jumped again to about £35, not sure why. Perhaps it'll fall again, I don't imagine they get many customers at that price.
https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20170904022341&SearchText=gridseed+blade.

So a couple of options there. But either way I would take a look at the fault finding to help weigh up your options.

[Nick4994]

Hi - I've managed to destroy one of my g-blades in a manner that I can't easily repair.
I had them on a raspberry pi all powered by a battery / solar set up.
It looks like the power jack on one failed, opening the negative, causing the return current to flow through the RFI bead to the STM32f103 ARM controller ground, down the USB cables to the pi, through the pi ground and back to the solar controller ground.
The pi survived.
Along the way the ARM and 3.3V regulator were destroyed - as in escape of magic smoke and 3.3V shorted to ground.
There must have been over 5 V of drop on the ground there to reverse the polarity on the ARM and regulator to destroy them...
When I power up on 12V, I still have the 1.2 V rail, the 5V rail derived from the 12 V rail, and the 5x 3.3 v rails.
Fingers crossed the GC3355's are all ok. 
I've done some probing tracing of the board to understand how the GC3355's are connected to the ARM.  Looks like the only connects are to the ARM's 5 UARTs and some signals to the uP1509 that genrates the 1.2V

I think I'll replace all the 0 ohm links between the GC3355's and the ARM's UART ports with ~100 ohm resistors to limit the current that can flow into the inputs under fault conditions and put a schottky diode reverse biased  across the 3.3V rail so the power rails across the ARM can't become reversed.

I have a tech background and am able to replace the STM32f103RCT6 ARM controller, but I don't have any firmware for it.   
Back on page 29, I see there was a firmware image from" J4bberwock" but this is now a dead link.
Does any one have a copy of the g-blade firmware any more?
I am familiar with Atmel AVR / Arduino and PIC but have no prior ARM experience.
I'm assuming Gridseed shipped these with flash read protection active?
Surely its not as easy as reading out the flash from the good ARM on the other side of the brick into the programing software and writing it out again to the new blank controller?

Regards,
Nick.

 

[Nick4994]

Nope - write protected, first thing the programming software asks to do is unlock the flash and erase the chip...