Lucky Miner 08 Power/Voltage Issue – Any Advice?

[liton25]

Hey everyone,

I’ve run into a puzzling situation with my Lucky Miner 08,
 and I’m hoping someone here might have some insight.

I’ve noticed that the miner is only drawing around 50W,
which is obviously too low for normal operation.

 I’ve tried a variety of original settings—like holding the reset button for 10 seconds,
 adjusting voltage and frequency channels, and even a full power cycle—but the power draw remains stuck.

Initially, the ASIC Voltage Measured in the interface was showing 0V on the right side.
 In the logs, I saw something like:

₿ (241631) power_management: 7F vout: 1.24, iout: 33.69
₿ (241631) power_management: 24 vout: 0.05, iout: -0.29
₿ (241631) power_management: 14 vout: 0.05, iout: -0.28
```
(The numbers aren’t exact, but basically `24` and `14` were both reporting around 0V.)

I opened up the machine and measured two sets of 12V rails; both read a solid 12V. I also tried reseating the heatsink. After putting everything back together, there was a brief period where things looked normal:

₿ (126451) power_management: 7F vout: 1.24, iout: 33.69
₿ (126451) power_management: 24 vout: 1.24, iout: 29.75
₿ (126451) power_management: 14 vout: 1.24, iout: 29.47

But then it switched again, and now it’s showing:

₿ (241631) power_management: 7F vout: 0.05, iout: -0.29
₿ (241631) power_management: 24 vout: 1.24, iout: 29.25
₿ (241631) power_management: 14 vout: 1.24, iout: 29.34

So in other words, `24` and `14` are back to normal, but now `7F` is reading 0V.
The interface also shows some voltage in the bottom-right corner,
so there’s at least some power going through.

Here are my main questions:
1. Could this be related to the way the heatsink is installed, or does it more likely indicate a problem with the power module/VRM?
2. It doesn’t seem to be a super rare issue. Among five to ten units, at least one has exhibited this behavior.
3. Does anyone have any recommendations or fixes I could try?

Thank you so much for taking the time to read this.
I’m relatively new to this,
 so I’m trying to give as much detail as possible.

 Any help or suggestions would be greatly appreciated!

[fromport]

₿ (241631) power_management: 7F vout: 0.05, iout: -0.29
₿ (241631) power_management: 24 vout: 1.24, iout: 29.25
₿ (241631) power_management: 14 vout: 1.24, iout: 29.34

So in other words, `24` and `14` are back to normal, but now `7F` is reading 0V.
The interface also shows some voltage in the bottom-right corner,
so there’s at least some power going through.

Is it hashing at all ?

My Lv08 with luckyminer os shows these temps.

Code:

₿ (416376) power_management: 7F vout: 1.23, iout: 31.91
₿ (416376) power_management: 24 vout: 1.24, iout: 28.06
₿ (416386) power_management: 14 vout: 1.23, iout: 26.28
₿ (416386) EMC2302: GET-Fan Speed[0] 502 = 3916 RPM, MSB 0x0F
₿ (416386) power_management: Board Temp: 48, 63
₿ (416396) power_management: TMP546_0 Temp: 63
₿ (416396) power_management: TMP546_1 Temp: 62
₿ (416406) power_management: TMP546_2 Temp: 58

And this is from the LV08 with the modified bitaxe firmware:

Code:

₿ (221401872) TPS546: TPS546_0 - Got Vin: 12.109 V
₿ (221401872) TPS546: TPS546_1 - Got Vin: 12.094 V
₿ (221401882) TPS546: TPS546_2 - Got Vin: 12.094 V
₿ (221401882) TPS546: TPS546_0 - Got Vout: 1.230 V
₿ (221401882) TPS546: TPS546_0 - Got Iout: 29.062 A
₿ (221401892) TPS546: TPS546_1 - Got Vout: 1.232 V
₿ (221401892) TPS546: TPS546_1 - Got Iout: 30.719 A
₿ (221401902) TPS546: TPS546_2 - Got Vout: 1.229 V
₿ (221401902) TPS546: TPS546_2 - Got Iout: 31.219 A
₿ (221401912) TPS546: TPS546_0 - Got Temp: 69
₿ (221401922) TPS546: TPS546_1 - Got Temp: 69
₿ (221401922) TPS546: TPS546_2 - Got Temp: 61

Can you post your temperatures please ?

Here are my main questions:
1. Could this be related to the way the heatsink is installed, or does it more likely indicate a problem with the power module/VRM?

Could be a lot of reasons.

To test you should first start by setting default values for freq: 485 Mhz
and default voltage: 1200 mV, save and restart.

Luckyminer basically copied the design of a bitaxe hex ultra and made it with 9 chips instead of 6
This is screenshot of the schematic diagrom of a the bitaxe hex ultra:
https://www.dth.net/crypto/miners/bitaxe/hex/set_of_3_BM1366_in_voltage_domain.jpg
VDD is supplied by a dedicated VR for 3 chips.

As you can see 3 BM1366 are connected to 5 Volt for the control, but the power of the computing part of the asic is daisychained in series.
3 x 1200mV = 3.6 Volt being fed to one voltage domain.
The original HEX has 2 voltage domains  so 2 x 3 chips in series
The LV08 has 3 voltage domains : 3 x 3 chips in series.
Each voltage domain has its own VR (voltage regulator)
The 7F,24 & 14 is the address of the VR on the BUS to the ESP32 microcontroller.
This setup requires that all 3 chips in series basically use the same amount of power so that the voltages over the 3 chips are the same.

If you let the unit go "cold" so switched off for 30 minutes (ambient temperature) and you plug it in and check in the log files, does it work
Maybe you can try to capture the log file as fast as you can ? That should show in all 3 are starting up at all or not.
If the temp goes to high it will protect the hardware by setting low fre & low voltage to not let the asic burn up.

2. It doesn’t seem to be a super rare issue. Among five to ten units, at least one has exhibited this behavior.

It could be chip issue, but more likely soldering issue
Weird thing is that all 3 VR domains seem to be affected.
I would have suspected 1 or 2 but not all 3 in a random sequence.

3. Does anyone have any recommendations or fixes I could try?

Thank you so much for taking the time to read this.
I’m relatively new to this,
 so I’m trying to give as much detail as possible.

 Any help or suggestions would be greatly appreciated!

[fromport]

I had bought 2 extra LV08's that I kept running on luckyminer OS for over a week before converting them to modified bitaxeos today.
First one was down less then 40 minutes before hashing again.
The second one was a little bit different.
At some point when I was soldering I grabbed the heatsink and "something" moved a bit.
I inspected and everything seemed normal.
I flashed modified bitaxeos and it started hashing, but only at 2/3 of capacitly.
From the log files:

Code:

₿ (102996) TPS546: TPS546_2 - Got Vin: 12.109 V
₿ (103016) TPS546: TPS546_0 - Got Vout: 1.195 V
₿ (103016) TPS546: TPS546_0 - Got Iout: 26.594 A
₿ (103026) TPS546: TPS546_1 - Got Vout: 0.023 V
₿ (103026) TPS546: TPS546_1 - Got Iout: -0.292 A
₿ (103036) TPS546: TPS546_2 - Got Vout: 1.195 V
₿ (103036) TPS546: TPS546_2 - Got Iout: 21.562 A
₿ (103046) TPS546: TPS546_0 - Got Temp: 53
₿ (103046) TPS546: TPS546_1 - Got Temp: 41
₿ (103056) TPS546: TPS546_2 - Got Temp: 52

Oops, no I had the same as person above.
I took the unit apart again an concentrated on the part that had moved
It turns out there are 2 heatsinks on the LV08:
A large one for the 9 asics and a smaller one for the 3 VRs (voltage regulators)
https://www.dth.net/pmt/luckyminer/img/VR1.jpg
https://www.dth.net/pmt/luckyminer/img/VR2.jpg
The only thing I did was push some of the pink heatsink stuffback to the area where it touched the VR (all 3 spots)
Screwed the heatsink back on the PCB and reassembled the unit.

Firing on all cylinders (I should say VR's) again:

Code:

₿ (4553526) TPS546: TPS546_0 - Got Vin: 12.094 V
₿ (4553526) TPS546: TPS546_1 - Got Vin: 12.062 V
₿ (4553536) TPS546: TPS546_2 - Got Vin: 12.062 V
₿ (4553536) TPS546: TPS546_0 - Got Vout: 1.230 V
₿ (4553536) TPS546: TPS546_0 - Got Iout: 34.688 A
₿ (4553546) TPS546: TPS546_1 - Got Vout: 1.229 V
₿ (4553546) TPS546: TPS546_1 - Got Iout: 38.250 A
₿ (4553556) TPS546: TPS546_2 - Got Vout: 1.229 V
₿ (4553556) TPS546: TPS546_2 - Got Iout: 27.531 A
₿ (4553566) TPS546: TPS546_0 - Got Temp: 70
₿ (4553566) TPS546: TPS546_1 - Got Temp: 75
₿ (4553576) TPS546: TPS546_2 - Got Temp: 63

Average: 5.25 TH/s
Expected: 4.95 TH/s

[liton25]

After multiple discussions and tests with the manufacturer,

if anyone else encounters the same problem I did—where the initial power (hash rate) is insufficient and can’t reach 110W

—try removing the heatsink.
If possible,
when reinstalling the six screws,
avoid over-tightening; 0.35N·m is the maximum

(based on my own testing, a light torque is enough).

For the other two separate screws, don’t exceed 0.25N·m.

Both over-tightening and under-tightening can cause insufficient wattage.