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?
hey bohoma, I just recently had an issue with my recently purchased Avalon Miner 741 as well... my issue was the 1 power supply I was using (HP 1200w hot plug psu + breakout board) was getting a low voltage from my American 110v power outlet, so it only produced enough wattage to power my Avalon for 10min at a time before it automatically shut down.
I did figure out how to make it work with that PSU, by changing in the Avalon Advanced settings view:
Status Tab > CGMiner Configuration > Voltage Offset setting that to -2
(I don't know if this is the proper way of setting things but it seems to work well)
Now my Avalon 741 works on the 1200w psu with the 110 v outlet, although the compromise is my TH is pretty pinned at 7.2-7.4 TH/s rather than being able to get 8 TH/s like it could with a proper PSU without the voltage offset. I am doing this and waiting until I can get the 1600w Sorcerer power supply (that is specifically made for the Avalon 741 miner) when it comes available again so I get the full range of TH.
One question I have: why are you using two separate power supplies? I have also made a similar search when researching my own PSU issues, and nowhere did I find it was proper to use two separate PSUs on an Avalon 741 (I only saw posts about people using the Bitmain Antminer with two separate PSUs, one for each board/side). The problem I see is that each PSU is separately trying to adjust the output to the machine (without knowledge of the other PSU). To me that seems like you might overwork both PSUs more than they should be, IMHO.
There may be no problem doing this with Avalons, but I have not seen it documented anywhere like i have seen with the Antminer.
Anyway, my recommendation is if you can do it get only one PSU and preferably something with a higher wattage ceiling so your avalon can get the full power (like the Sorcerer 1600w that Canaan makes).