Yeah, I managed to detect one chip on the board. FINALLY :-).

Problem seems that the chip wasn't soldered properly. For this version, I first "reballed" the chip itself with some solder paste and then soldered it on the PCB. And now, I have a communication. The chip is responding!

But somehow, the current is very low and the chip seems not really hashing.

But I'm really happy that I can now talk to the ASIC ;-). Thank you all for your help. I really appreciate it!

Thanks for reviewing my schematics.

I have now reworked a few things.
1. I supply the VDDIO_18 pin with 1.2V (using the chips power supply)
2. Checked if the crystal oscillator is still working with 1.2V and it is.
3. 0.8V supply is generated from the 1.2V. So, if the power supply is switched of, the VDDIO supply is also off.

I think from the electronic point of view, I'm probably using the chip well within its specs.

But I still don't get any response from the ASIC.

I'm open for every other clue 

Just an additional information. I bought BM1366AL chips from NBTC. Could that be a problem? Because on discord I have seen that someone else has problems with the AL variant to be detected on Bitaxe Hex.

Are there any official Infos available?

The first page contains the modules and how they are wired. It is important to note, that I'm right now testing PCBs with just the first two ASICs assembed. The level converter and the second 2 ASICs are not assembled. And VDD1 is now directly supplied with 1.2V from the power module (TPS546B24A).

https://nextcloud.emicrotec.at/index.php/s/NmR9skFPHfPaaLW

Thanks for the reply. I think 2.4V is just fine because I have 2 of them in series and each chip should get its 1.2V operating voltage. But as I said, I measured an unequal distribution of the voltage.
Regarding cooling and the heatsink, I think you are totally right. I powered up the first board because I thought the chips would just getting warm as long as I don't let them hash. But I think I was wrong with that.

I have now assembled a couple more of my boards but on none of them I can detect the ASICs. I always get the message 0 ASICs detected but expecting 4.

And because of not getting any communication with the ASICs, I decided to have a board assembled with just 2 ASICs in parallel and supply them with 1V and 1.2V. But I have still the same issue that I don't get anything back from the chip and the chain is not detected.

I'm sending some data to the ASICs with 115200 baud on the UART with 1.8V level. The BI (busy input) pin is low. The 25MHz oscillator is running.
So, I'm slowly running out of ideas what I can do to get it up and running.

Has anybody an idea what else I can test?

Thanks!

Hello.

Maybe, some of you can help me out. I designed a board with 4x BM1366 ASICs based on the Bitaxe and Bitaxe Hex.
The last couple of days, I tried to get it up and running, but I get no communication with the ASICs itself. The controller is sending data to it, but nothing is coming back.

What I observed is, that the current consumption is increasing when the chips are getting warm. And at the beginning, I had no heat sink (or a very simple one) on it. Could it be that the ASICs got damaged because of too much heat and current?
Additionally, I'm powering the 4 ASICs with 2.4V because 2 of them are in parallel an then they are in series with the other 2. So, overall core voltage need to be 2.4V. But what I see is, that the voltage is not equally distributed over the ASICs. The first 2 ASICs have 0.8V and the bottom 2 are supplied with 1.6V. May this be a sign that the ASICs are damaged?

Should the clock signal be available on the inverted CLK output pin of the ASIC? Because, I don't see anything there.

I hope someone can help me out.

Thanks,
Andreas