Bitmain APW7 Electric Fire with Baikal BK X Units

[Cryptostevo]

A few days ago I swapped all my APW3++ PSUs for the new Bitmain APW7 PSU units on my Baikal BK Xs. After day one, I had an electric fire that melted one of the hashboards on a Baikal BK X unit. The next day two more Baikal BK X units end up with melted hashboards. All 3 damaged Baikal BK X units had APW7 PSUs, and all 3 had the far right dashboards melt. The other hashboards appear to be ok. I found 5 of the capacitors had fallen off the melted hashboards (see pics).

Anyone else having issues with either the APW7 PSUs or Baikal BK X (Giant X 10) units?

Here are some photos:
https://imgur.com/KOzZriE
https://imgur.com/8WR4u8J
https://imgur.com/cdMxMfT
https://imgur.com/Vz0WRvi
https://imgur.com/O6Z9ziy
https://imgur.com/JQgEpiX
https://imgur.com/DZVWcEy
https://imgur.com/Nl3h8Vq
https://imgur.com/fNjOOFy
https://imgur.com/nWoyA4k
https://imgur.com/KbqfjEE

[philipma1957]

Thanks for info.

I won’t say if it’s not broke dont fix it.

And I won’t say fool me once shame on you,
Fool me twice shame on me.


I will ask a few questions.

Power rating for new psu is?

Power rating for old psu is?

120 or 240 volts used?

Power draw on the baikal bx k units?

[TGJ]

Were you using PCIE splitters?

[Cryptostevo]

Thanks guys on the responses/questions!

My farm runs on 3 phase 4 wire to the PDUs at 240volt, and then the PSU plugs into the PDUs.
I checked the PDUs and they are all checking in around 230-240volts at the receptacles.

I do profit switching with the Baikal BK X, so they range in power draw from 120watts to 630watts depending on which algo they are on.
The APW3++ is setup for up to 1600watts. Specs: https://www.eyeboot.com/antminer-apw3-bitcoin-power-supply.html
The APW7 is setup for up to 1800watts. Specs: https://shop.bitmain.com/product/detail?pid=00020180621115441375Ioit8oeJ06DE
I have one PSU per each miner and no PCI splitters are used.

I upgraded as the efficiency of the apw7 was 1-2% better than the apw3++ and I was able to buy the apw7 and sell the apw3 for about the same cost.
Today I went through and removed the apw7s from the baikals and re-installed the APW3++ PSUs instead.
However, all my other machines running the APW7 have not had any issues, a mix of Innosilicon D9, A9, S11 and Bitmain S9i.

I have an electrical engineer coming on Tuesday to see if we can diagnose the issue too.

Thanks for the feedback!

[jbillk]

Biakal recommends ATX power supply. Not sure that has anything to do with it. Perhaps cleaner power from ATX.

[dagarair]

Damn man.  You probably just got a crappy PSU =(

I don't believe in coincidences

That's horrible..... 

[treanski]

would be interesting what baikal says to this issue

[Cryptostevo]

Forgot to update this. The problem was never fully figured out. After breaking down the baikals that caught fire it appeared the ones that caught fire had a lot of dust in between the capacitors on the board. Since there was no conformal coating on these boards (guess Baikal wanted to save a buck or two per board), the dust piled up and during a humid month the dust and moisture allowed for a path of conductivity. I took all my baikals apart, cleaned them and applied conformal coating. I then went back to APW3++ PSUs for the baikals. Since then, no issues. I also haven't had any other APW7 fires with any other units.

[dagarair]

honestly, i have 100's of APW3 s and have only had 1 ever die on me but an easy death not a firey one.  I have 12 APW7 and already 2 have died.  I don't like that PS at all.

[jstefanop]

Shit...looks like either bad PCIE connectors and/or low gauge wires used on the new PSU or some sort of very bad short on the PCB. Look like 3 hashboards per unit so a max of 200W per board? Two 6 Pins should handle that current fine even though its a bit on the high end, but not if they are using cheap 18-20 gauge wire.

Units look very dusty so something might have also shorted on high side which would cause that sort of burning/PCB damage.