These bad boyz have been chugging since 2023.
Software-wise, the machines are a disaster unless we pretend that the GPL doesn’t exist. The machines don’t have SSH access, but the control boards expose a UART port, and you can get root access if you have a Flipper Zero lying around. The password is root.
If anyone’s interested in seeing what’s inside the machines — I recently managed to fix yet another failure of ASIC mining hw. The Z15 machine has three hashboards, each of which has three ASICs. This is what the hashboard looks like. The hole in the PCB is due to a previous failure in the power circuitry.
The same failure happened again on the same board. This is what it looked like on the other side of the board.
And this is what it looked like under the heatsink.
I removed the SMDs related to the affected ASIC and drilled out the burned part to get rid of the s/c.
You can see that the ASIC came off as I removed its heatsink. The other day, I had to use some weird thermal epoxy glue instead of thermal paste since all the thermal pastes I found dissolved in oil.
However, the s/c wouldn’t go away, so it was time to take out my new thermal camera. I connected the board to a regulated power supply, set the voltage to 12V, and limited the current to 10A. Here’s what I got.
After more drilling, the mf still wouldn’t go away, so I took another video. Btw, drilling a PCB is no fun. I was essentially burning the material away and subsequently inhaling it instead of drilling it. It seemed to be a four-layer PCB.
After some more drilling and cleaning, the s/c disappeared. I connected some signal paths on the PCB by making some educated and some completely random guesses, and I used the thermal camera again to check that at least the last ASIC still worked. And it did!
By the way, this is how I started in 2017 as a kid. There are six water-cooled Nvidia 1080 Ti graphics cards at the bottom. They were upside down in case of a leak. The glass on the right was catching one. The GPUs were mining ZEC until ASICs took over, then ETH.
I was using distilled water, but life started forming in it quickly. I solved it by adding some windshield washer fluid I found. Nothing wanted to work initially, but in the end, the GPUs were mining until ETH switched to PoS.
Right above the GPUs was a little control room – or at least a cabinet. The two buttons on the bottom left were the UI for my family. The transparent food container beside the UI was a case for a transformer with live AC, powering the blue relays sitting on top.
The tank wrapped in a towel was an expansion tank for the cooling system. The Arduino in the middle talked to the computer and controlled a “cooling backend” via the relays.
This was the cooling backend. The insulated garden hoses from the previous photos, acting as pipes, were connected to the white boiler, which served as a heat exchanger. The heat from the GPUs was being routed to the house’s heating system.
Making the systems talk to each other was fun, as you can tell from the plumbing. I needed to teach the legacy system new tricks, and long story short, it fucking worked! The GPUs were helping with heating at all times, and they were happy when the furnace was at full blast.
Most of this is gone, though. The ASICs from the video replaced the GPUs and the furnace. All the plumbing is gone. Only the boiler and the electric heater didn’t move. Deprecation in Zcash runs deep.
What might be surprising is that the mining setup has a positive effect on CO2 emissions in this case. Unlike the furnace, the machines have essentially zero emissions. The latest proper data on energy source distribution I have is for 2023.
In that year, the ASICs consumed 32MWh. The solar system directly offset 1/3 of that and pushed three additional MWh to the grid. The graph below describes the production of the solar system for each month of that year.
The remaining 20 MWh were sourced like this. The house doesn’t use any other heating.
