Cold start -> buggy control board?

[cmanmatt]

I'm starting to schedule my Antminers to turn off and on to take advantage of time of use power price. 

I've noticed if they are down during the day and then I start them late in the night that they come up very buggy.  Many of the hashboards won't show up, temperatures are totally wacky, bad to no hashrate on some.  Then if I restart them after a few minutes they get better and everything starts acting normal.

Have others seen this? I'm wondering if maybe condensation is getting on the control boards during the day as they cool down (it has been very rainy and humid lately).  Any other ideas?

[1715128345]

1715128345

[1715128345]

1715128345

[1715128345]

1715128345

[MinerMEDIC]

My intuition says the internal interconnects between the epoxy chip and the ASIC are to blame. These chips will warp if you breath on them wrong. Bitmain knows this that's why the controller will heat the hashboard during initial start. It will attempt this several times before giving up on the hashboard.

[OgNasty]

Starting miners cold is hard on them...  You could try starting one of them up first and letting the room heat up before starting the others.  On buggy units in the past, I've had to go as far as heating them up with a blowdryer before they would start up correctly.

[Steamtyme]

How cold are you talking?

I get that you want to take advantage of the better pricing but, could you leave 1 unit running to take advantage of it's heating capabilities. Again not sure of your space or number of miners but by leaving 1 or more on you can keep the ambient temperature in a happy range for the rest to start.

[cmanmatt]

UPDATE and more info:

So tonight, everything started up just fine after still being shut down during peak price hours.  So based on that, I'm quite sure yesterday I must have had a condensation problem causing the antminers to have misc. electrical/connection problems.  Yesterday was very different weather than today.  I'm in southern FL so it definitely isn't getting cold.  But we had tons of rain the last few days so I think when I turned the hot miners off but kept my exhaust blowers going (my setup is in the garage) it was pulling in humid air so as the miners cooled to ambient they must have gotten moisture in the control cards, etc.  Today it wasn't raining anymore so it wasn't nearly as humid.  When I turned things on everything came up perfect and started hashing away no problem.

My solution next day will be to switch off the exhaust blowers right when I shut down the miners so it will stop airflow and even keep residual heat in the machines until I turn them back on.

Just additional FYI on my setup if anyone is interested:
- Have ~40 antminers (20 L3, 7 S9, 4 A3, 10 D3)
- Have 8 220 V 30 amp circuits so I can't quite run all my machines at once so I swap them out based on profitability.
- Started at the beginning of 2017 and have built out 3 "mining boxes" in my garage which have exhaust blowers venting through 12 inch duct through the attic out to the soffits to exhaust outside.
- Just got on a time of use plan so now my offpeak price is around 7.5cents/kwh which makes things way more profitable but I don't want to run during peak hours unless a particular coin profit margin over power is high enough.
- I also have some GPU units I run in the house and play around with different coins with those (currently mining Zcash)