You are way overclocking those boards.

Most of the 54 chip boards have a default clock speed of 575 to reach a total of ~4.8th. Even the custom 5.67th models only ran a 675 default clock. It looks like you killed one of your boards with that overclock.

Also the ASIC chips are NOT ok in your second screenshot. It should be seeing 54 and it is only seeing 48 meaning there are 2 dead clusters of chips which is why it will not hash.

Disclaimer: This is the bitcoin forum, please post in the proper section.

I dont even know of another person that bothered trying to mine on such a low end card. I would get at least a 1060 6gb if you are looking to mine at all.

Yes you can power the GPU separately from the motherboard. 2 PSUs is fine.

They are built to run 24/7. Powering them up and down is actually worse for them.

The build quality can vary depending on batches and a number of other things so there is no way to quantify this. You may have one die in a month and another runs 5 years.

The only user servicable parts are the fans, cables, and controller. (If it is under warranty do NOT do anything yourself without bitmains permission or it voids your warranty)

Board level repairs require a fair amount of experience and knowledge that is not publicly available. 99% of people will have to send them in for repairs.

S9s are known for having faulty hash boards. That is really the main issue with them. The only other issue I can think of off the top of my head is they are a bit more sensitive to heat than other comprable miners in my experience. As long as you keep ambient room temps down where they are that shouldnt be a concern.

You dont have to run their PSUs, you can always source other options as many people on this site do.

You need to post this in the appropriate sub-forum. This is for bitcoin mining only.

I can confirm the board you selected works just fine with 6. If you go with 9 you will most likely run into a bunch of problems that create more downtime and increase ROI time.

You can always cut a hole in the room and exhaust via the new hole

Of the first 50 6 card rigs I built back last September I have had 2 motherboard and 6 video cards fail. The real interesting part is these rigs all ran only passive risers yet are still chugging away just fine.

I strongly feel it is about the setup and quality of parts used, not the quantity.

Yea I forgot to mention you should really be using linux with more than 4 GPUs.

I am going to have to disagree that 6 card rigs are unstable and hard to setup. I have access to a very large number of machines running 6 cards with no issues. Just because amateurs cant figure out how to make it work does not mean it is not viable.

I will agree that once you pass 6 cards as most motherboards only have 6 physical PCI-E connectors you will have problems. Adding PCI-E splitters and things just complicates things and adds a whole new layer of issues to troubleshoot.

For example. In the past week i have tested 4 motherboards.

MSI B250 Gaming M3 - would not work with more than 3 cards without issues. Even adding a 4th created a slowdown on the other cards.

Asrock B250 Gaming K4 Fatal1ty - 45 minutes of BIOS tweaking and testing had this board working with 6x RX580s.

ASUS Prime Z270A - Less than 30 minutes of work had this board working with 6x RX580 as well as 6x 1070s using PimP, Simplemining, and EthOS.

Asus Prime Z270P -  Less than 30 minutes of work had this board working with 6x RX580 as well as 6x 1070s using PimP, Simplemining, and EthOS.

There is nothing wrong with 6 card rigs. If the rig is powering off (not windows crashing or shutting down) then you have a power supply issue. When all 6 cards are drawing power it is too much load and will trip the PSU into restarting itself. Remember that as a power supply ages its output can slowly diminish. Depending on how hard of a life that PSU has it may just be on its last legs.

Just as an FYI to you guys you can power GPUs seperately from the risers and motherboard with no issues. You dont even need to power cycle the cards when you power cycle the motherboard. I have tons of rigs running 600w ATX PSUs powering risers and the motherboard with 94% efficiency server PSUs on all the cards.

I had a bunch of asrock H97 anniversary boards that required me to use a 16x to 16x riser to activate the full length slot. Not sure if it is the same with that board but it might be worth a shot if you cant figure anything else out.

It has nothing to do with the pool. Its the S7 itself. Sometimes when you restart cgminer the boards dont come back. If you restart it again they usually do come back but running on a multi pool where you are restarting cgminer over and over exacerbates the issue.

Every time the miner restarts cgminer (aka switches pools) there is a chance a board will not restart. The simple fix is not to mine on multipools because there really isnt a way around this issue.

You would have to send it in to be repaired. There is nothing user servicable about these boards.

bitmainwarranty would be your best bet depending on where you live

S7s need to see both fans and the fans need to be in the expected RPM range based on the voltage the fan is provided with by the controller. If you replace them you need to match the fans as close as possible to the OEM versions

Funny, it shows as the 39th most profitable coin to mine for me....

you cannot mine bitcoin on anything but specialized asic hardware. PC's have not been able to mine bitcoin for years now.