The problem is your way of testing:

PCB temp is up to the ambient conditions of a miner.
The original FW is running roughly 620-650MHz and the energy consumption is ever rising exponentially when rising the clock speed, also the temperatures are rising (more energy = higher temperatures).
Fan set and all other settings are up to some temp measurements while single board test and boot procedure.
Further mV settings are according experiences regarding optimum IC temps for best value of has hash rate and efficiency.

Nevertheless there is a much better FW available and a better cooling system.

Are you sure?
S9j??
I rather believe it was a T9+, but anyway, why should it break with our software? You exactly know, that changes in the shell can easily set back to default.
I testet it with several miner types: e.g. I flashed D3 firmware on my X3 and A3. Sure, did not work, but when flashed the original FW from Bitmain´s download website, the miner was like "new".

Our software is running stable on S9j

?? you checked it like that or it is your wish?

its not working on my S9

Error when flashing --- "incorrect firmware"!!

we are selling small units as well

the magic word is "liquid cooled"

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we sell that system.

1x 20" Container - 250kW rated power hosts 108 miner
1x 40" Container - 810kW rated power hosts 324 miner

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please contact me consulting@raunegger.com

Incorrect firmware!!!

with the link only Basic is to download

S9 miners March Batch and S9i miners May Batch are not accepting Basic.tar

we are running in liquid cooling system - is there an option to switch off fans?

how to get your software for testing?

maybe dolle did not find any solution - but I solved it

mail me pls @ viennacalling@me.com

no need. I am happy how it is.

thx, that is very kind, but my "system" is already deployed on some thousand S9 and S9i miners.
myself I am owning 2000 S9/S9i and 400 A3 - so no more proof and/or reference needed.

no, it is not for free and it is not "custom firmware" - so no open source. sorry

so what?
even 14TH machines are running the same firmware and the results with same freq/mV are same as well .....
ASIC chips are same make, same foundry but different quality (which is a normal matter of production process).

I testet it on a March 2018 Batch - it is a 13,5 TH S9
No, I selectet 631MHz, as I know, that this is 13,5 TH in total. Stock speed??? There is no "stock speed", there is usually "autotune" and the controller board is checking, which avarage of frequency each hashing board (chain) with the 63 ASICS is able to perform to reach maximum 13,5 TH.
If you have read the bmminer source code, you will have recognized, that the firmware is limiting the possible hashingrate with a maximum of 13,5 TH. So any increase of defined parameter which would lead to a higher hashing rate is not possible.