See Ohm's law https://en.m.wikipedia.org/wiki/Ohm%27s_law
...plus other electrical engineering theory.

I can't make you understand electrical engineering with few forum replies.

It looks like there might be something wrong with the hash board connected in chain 1 (usually data cable port J1).

Look at the Zeusbtc website, there is a Canadian repair center location.
https://www.zeusbtc.com/RepairCenter.asp

The math does not work like that.
The current does not stay the same, as you presume in your calculation.

The input current they list is the max. input current for lowest allowed input voltage, so for 100V.
So the nominal power from the wall is about 20W.

In 230V systems the current is lower, close to about 0.1A.

Based on all the value readings, and ECHU, your third hash board is broken indeed.

ECHU (error code hashing unit) for it is 131073.

To figure out the ECHU sum meaning,
we need to do "reverse sum math".
131073 = 1 + 130172
, in which:
1 = CODE_IDLE
130172 = CODE_HUFAILED

See more here, in Table 4. -> https://bitcointalk.org/index.php?topic=3224256

First things first, can you post your log?
Please use the "code" function ( # ), while you post it.

It seems to be hard to find 277V input psus.

Two pcs. of these (one for left side PMU board and one for right side PMU board) will work.

• HP 1200W Common Slot 277VAC Hot Plug Power Supply Kit (717359-B21)
• A breakout board with 6-pin PCIE power cables.

I found an old thread about the subject,
I take no responsibility about the suggested psu models: https://bitcointalk.org/index.php?topic=1206101.0

You can also find some in eBay.com with search "277 psu".
Again, I take no responsibility about the products that come up with these search words.

Thanks! I like the hardware p**n, especially the rare ones!

Ok, that sounds good and reasonable.

If possible, use some protection (escrow, Paypal) or something with that seller.

You are asking us, how much you can ripoff us here at the forum by reselling some units you found?

That's got a bad taste in my mouth.

Mind sharing photos? It's been a long time since we have seen an even number S model design. I'm curious what a S20 engineering sample looks like.

I would go cleaning with canned pressurised air and isopropyl alcohol.

I'm lotto mining at solo.ckpool with AvalonMiner 841 ( low power firmware, 8 Th/s hash rate).

It has been warming my summer cottage in the winter time.
So the actual cost for mining has been little less, because I have benefitted from the heat.

Now that it is starting to be summer, I think I will shut it down for summer.

@fccs
Philipma1957 has said positive feedback about HMTech.
https://www.hmtech.co/services/

Have you asked them for the M20 psu repair or psu replace?

There might be some differences between the models.

Zeusbtc has a psu model correspondence table here:
https://www.zeusbtc.com/RepairDetails.asp?ID=277

I don't do escrow, try asking philipma1957

@NFW
I agree with you.

For mods, I don't know why you deleted my post.
I think if someone refers to my name and opinion,
I have the right to agree with/without additional comments, or disagree.

I've used Myrig for few Ant R4 repairs without issues.

But you can find a service in Europe via www.zeusbtc.com

See the end part in your log sample..
Some chip is running over max. temp at 101C (max. level is 98C).

Is there some damage is heat sinks or a bad contact between heat sink and chip?

Is your ambient temperature too warm?

Are the fans running ok?

Maybe use Myrig or Zeusbtc for the one hash board repair?
It's crazy but I guess that a paid repair for one hash board can be cheaper than sending the whole miner for Bitmain's own warranty repair, because of the down time.