Bitcoin Forum

Hi

I have several damaged Boards from S7 after the warranty period.
I thought about building a tester for testing individual chips, voltage, protocol, UART, etc.
I read the documentation but not too much I learned
I measured the voltage that generates a DC-DC converter and is about 8V to the chain chips

Where to start?
It is now available schema for the board?

Bitmain has never released schematics of their miners and most likely never will.
As for data on the chips themselves, https://bitmaintech.com/files/download/BM1385_Datasheet_v2.0.pdf

About the only person who could shed any light on this for you is sidehack.

Maybe he'll show up & share some info on whether what your asking is something you could do or not  ;)

I did work up a test Compac with BM1385 but could never get it to work. The friggin' 0.4mm pitch ASICs are a bear to work with, plus that they're impossible to reliably acquire thanks to the chipside heatsinks, got the whole project scrapped in prototype.

I haven't looked over an S7 board specifically for chip stuff in a while (been focused more on power) but I believe there are test pads between chips if you can get to them around the heatsinks. You could at least verify where signals are going.

If the DC-DC is at about 8V, there's something wrong. It should start out around 9.3V and if you provide 3.3V to the 3.3V pin on the 18-pin header (or just plug the cable into a powered controller board) you should see that jump to 10.2V or so unless there's something very wrong with the PIC/DPOT parts of the power circuit. There's already a couple threads on that subject though.

I made some steps and measured the voltage on the individual chips .
https://i.imgur.com/WZjjpi9.jpg
After connecting 3.3v voltage jumped from 8.32V to 10.56V .

It comes out that three chips are connected in series, then fifteen groups are connected in parallel

That's about exactly what you should be seeing, so it means the power circuit is functional. Next thing would be to poke reset, TX, RX and clock lines at the 18-pin and see if those signals make it all the way to the last chip in the chain. This should be done while the board is powered up, of course.

I understand now that I connect the USB to UART and see what appears on the terminal ?
The control board detect the only one chip.

which chip is first and which is last in the chain?

Where'd a USB to UART enter the picture?

Signals in Antminers go uphill, so the first chip would be on the lowest-volt node and the last is at the highest. I'm not sure offhand where those are but it  shouldn't be too hard to tell.

I have a FT232 USB to uart converter and i will use to connect to the 18 pin header