Hi Joel coin,
thanks for elaborating on your experience. Your point about two psu's is well taken, however, this information was taken from Avalon site itself.  Check this link:

https://canaan.io/question/avalonminer-741-power-supply/

I am in Europe and using 240V input, and I always thought that offsetting the voltage by -2 will probably have a different effect compared to 110V input.

what you are saying about the two psu's could be valid, but I don't have a big psu to validate and don't want to spend more money on this miner as I am doing it in order to learn and explore new opportunities.

I will write to Avalon tech support and I hope they can confirm, otherwise they should correct their website.

thank you all for the support. After replacing the power supply it started to work in the range of 5.8THs. I used two 850W Corsair power supplies as these were available and the change was noticed immediately after. The question remains open whether I should aim for a higher figure with the Avalon 741 miner?

Europe 240V

the only way to confirm is to replace with a higher wattage psu. I found this one but i need to buy two.
http://www.corsair.com/en-us/cx-series-cx850m-850-watt-80-plus-bronze-certified-modular-atx-psu-na

do you recommend using two psu units or just buy one psu with a high wattage?

 

this is the one

https://www.bequiet.com/en/powersupply/387

what do you suggest? should both psu replaced by one psu with 1300-1500W?

there are two power supplies, each 650W.

Well, Now there seems to be a new hardware issue. After running for few hours, one side of the miner stopped working. Switching off the power supply and on again, it statrs working but few minutes later it is off again. I hope its a power supply issue. Otherwise the low mining speed could be a result of that one side being faulty. I hope i can test it tomorrow with another power supply. Also waiting for a reply from Avalon support 
 

AUC is green, and at the back of miner 4 green with one blue on the top

it stays like this for long, and the 1600+ figure remains there even if it starts mining. Now i did a total reset and waiting, still at 0 GHs.
I tried wit several pools slushpool, kano and now trying with nicehash as the primary pool.
will keep you posted

I just did a reset of CGminer to default and started the miner with -2 setting. I will send a new screenshot after few hours, but in the meantime, pls take a look at the image if you can spot any problem.
https://drive.google.com/file/d/0B9NWjdgjoBrWU3FqN3lXSTdsbUk/view

CGminer shows error code 15, which I presume is a normal one?

I recently purchased a new Avalon 741. After completing configuration and starting the first few test runs, i realized that it’s producing a very low mining speed (around 500GHs only). Whereas it is expected to produce far more speed upto 7THs and maybe higher.

I tried with multiple types of pools such as slushpool, kano and nicehash, but none of it could produce anything beyond the average speed of 500-600GHs. I don’t know if I am doing something wrong or if issing anything here, but everything seems to be normal in terms of the settings. For example, the network latency to slushpool and nicehash is around 30ms.

Did anyone faced the same issue with Avalon miners to help troubleshoot and fix this problem? maybe some settings in the CGminer software that I am not aware of?