Keep them on. The thermal cycling from repeatedly letting them cool down and then heat up again will stress the solder joints and chip/heat sink interfaces.

AFAIK the problem is with Core - not cgminer. Core dropped support for direct mining to it long ago shortly after ASIC's hit the market and sent CPU mining the way of the dinosaurs.

Um a simple search for high leg delta turns up https://en.wikipedia.org/wiki/High-leg_delta which explains it all...

Is not a matter of preference, high-leg systems are not really used anymore as the setup was always a compromise. In the US for several decades now straight 3-phase wye is preferred but as you said that requires as step down xmfr because most miner PSU's top at 250VAC -- feeding them 277 is out of the question.

It happens from 2 things:
Too many plug/unplug cycles, even the best available pins for PCIe plugs are only rated for 25 cycles. El-Cheapo's as few as 5 cycles and whatever plating was on the pins is gone. Once the plating is damaged things go down hill very quickly. If the miner or PSU are used, who knows how many times the plugs have been cycled...

Using aluminum or too thin wire for the PCIe cables. The wire itself is part of what removes heat from the connectors. If it's only 18ga then the pins WILL become warm, the plating will begin to oxidize and eventually fail.

[2021-10-26 01:34:33.197+11] _bloks_add(): BLOCK! Status: 1-Confirm, Block: 706643//...00003e1c44976d2b Diff 72.5T Reward: 6.304597, Worker: Sei_ski, ShareEst: 61886788304974.0 61.9T 326.67% UTC:2021-10-25 14:34:33.167625+00

Happy Happy Joy Joy!
The dry spell is over!

What? Someone doing it themselves? But that's so harrrddd!  

Yes is the one that is most used. Be aware that the 3B+ will NOT work.
The OP mentioned using a RasPi 2B - have you made sure that you loaded 2B firmware?

The 277v is what you get from 480V 3-phase wye connection. Running from the center neutral point to any 1 of the phases gives 277V. In the past that connection was mainly used for lighting in factories that use 480V 3-phase to power their equipment - the balasts used for large flouresent or HPS lights has taps covering a very wide rage of voltages with 277v being one of them. Yes that is a problem for miners because as you said, most top out at 250v rating and running anything higher is a very bad idea...

As it says on the home page, registration is required for both the solo and main pool. Address only was stopped several years ago and only folks who set it up that way before the change can still use their legacy address(s).

A snippet from Kanopool Help area:

You pretty much hit the nail on the head about mining chips needing to be viewed as mixed-signal devices when designing them and doing routing. Look up posts by 2112 as he is the local Forum guru on it. He and I have had several lengthy discussions about this several years ago.

Correct that Foundries do not design chips. However, Kano is correct in saying that Foundries DO work together with their customers when new chips are being designed and even more so when the chips are a bleeding-edge node size. Fact is, Apple, Cisco, Broadcom et al paid for most if not all of the development of equipment and techniques used to produce the various nodes - not the Foundries. BUT it was Bitmain and other miner chip makers who gave the Foundries practical experience in actually producing gazillions of chips for the ever shrinking nodes. As noted many times before, mining chips are extremely simple circuits not coupled with other complex data support things, not subject to loop closure time errors, and which operate 1:1 with clock cycles. If a core or reasonable multiple cores screw up - no big thing, the chips can still be used (and the production process tested). That makes them perfect test articles. Using the actual chips that Apple, Cisco et al have are far too complex and expensive to test like that - if they have a failure odds are the much higher value chip is trash.

As an aside, As Kano said, mining chips are most like GPU's - each chip has a massive number of cores. For example, per jstefanop the chips (from BitFury) in his Apollo have ~4,000 cores in them. My guess would be 4096...

Having gone rather OT here, I now return us back to our regular scheduled programming:
Heh - sold a bit of BTC when it hit $65,550 -- considering the recent drop, ja I missed out on selling at ATH but nonetheless great timing eh?

Because cgminer is sometimes included in malware programs to mine in the background without the PC user knowing it, Norton and most AV programs erroneously tag cgminer as malware. Just tell your AV program to ignore it.

Also there is a newer version of cgminer, it was updated by Kano to run Sidehack's latest stick and improve operation of his older ones. The whole shebang for it is here.
Trimmed version dealing with using the Win binary,edit: The Zadig USB driver is here https://zadig.akeo.ie/

Not really. The basic gate structures needed for the logic are extremely simple and were set in stone ages ago. The key point for mining chips is that the signal pathways need to be laid out by hand by someone who knows WTF they are doing and NOT use any sort of autorouting which will *work* but not produce the fastest possible signaling speed. At one time Bitmain had the best person to do that but lost him several years ago...

Clunkers like the A1 done by Innosilicon for Bitmine.ch back in 2013 and Canaan's 10nm chip used in the 921/941/951 are perfect examples of how not to do it. The A1 used a lot of pre-designed standard IP blocks for both chip I/O as well as the logic cores and while Canaan has always emphasized using custom blocks tailored for speed they blew it on the signal propagation times within the chip. The end results was that the chips were slower than should have been and used a LOT more power as well.

Talk about cutting every fraction of a penny they can on production costs... That is taking it too far. The only reasoning I can see is someone decided, "if a customer wants to use the mobo plug then they have access to something like the Wikipedia on ATX and can look at the pinouts. Who needs colors  `cause they would know the colors from the same spec sheet as the pinouts!"

In that wiki, search for "color" to see what the 20-pin plug is supposed to use. I hope they did not also decide to use aluminum wiring for the flying leads... Twits.

@ altruisticminer  Faboo! Merit given for letting us know you got things worked out  

@ OS2sam, all the wires the same color? If so then the PSU does not meet the ATX standards - those mainly deal with the physical sizes, AC power connection and cooling vent locations and of course, wire colors. The PON signal wire is supposed to be green and blacks are supposed to all be returns...

Ja, however the S19's are already using 5nm chips so guess what? No newer tech on the horizon for until at least middle of 2022...

That said, I've been saying that the node-size race for mining chips is coming to an end since 7nm. The cost/rewards are just too far out of balance to go below 5nm and since TSMC changed their priorities and pricing the 5nm node is now all but shut out for mining chips.

Hmm, last real post was July 05, 2021, 08:57:40 PM and now today, a sudden flurry of posts by single-digit post count folks...
Looks like someone opened the SPAM floodgates  

Did you even try to look at other topics in this section of the Forum?
Just a few lines down from the top you will find the the existing topic with the solution to the used Innosilicon miners kerfuffle https://bitcointalk.org/index.php?topic=5355134.msg58141121#msg58141121

Most often farms use filter walls to keep out the bugs & dirt while still having enough airflow - you want to keep the air velocity through the filters (and ducting if any is used) as low as possible to reduce frictional losses so that means you need huge filter surface area. In hot areas they very often use wet-filter walls where the filters are kept wet by sprayers or drip feeds. That of course makes them act as swamp coolers and substantially lowers the air temp coming through them.

What's worse is that some folks think it's not just ok but part of their vegan mission to force their pets to be vegan...

Hate to tell ya this folks but cats, dogs, most lizards, many birds, et al are either carnivores or at best, omnivores that prefer meat but do also occasionally eat plants when needed. They simply will not get the nutrients they need from only plants and will often practically starve themselves if not fed what they are born to eat or at least something resembling it.