Antminer D3 low hashrate and faulty boards

[soroosh]

Hi

This is my first question, please be patient with me.

I have two D3 ( December patch - 19.3 GH) for about 4 months, The miners was working good for about a month and I get a lot of HW errors and ASIC # lower than 60, and finally one board disappeared from status page. This story happens for 3 of boards and 2 of them only had lower than 60 ASIC chip.
I shipped 5 hash boards back to china for repair.
I have pretty stable voltage and the maximum chip temperature was below 85 degree.

What I did wrong? If there is a problem with this patch or I must run miners in a very cold temperature or something I didn't know?

Regards,
Soroosh

[Truthchanter]

I just started RMA for D3 as well for faulty boards.. maybe with the custom bios undervolt it works better?

[soroosh]

My last board was running with 350MH, default is near 500MH. Unfortunately I lost the last bloody board last week.
Underclock is not the answer, how could undervolt this boards?

[llanaio]

D3s are barely worth running. I think they're not worth returning as the shipping costs will be more than the miner will ever make. (IMO - you may see it differently, but do consider the math.) Fortunately, they only consume power relative to their hash power, so it's probably more economical to run them with fewer boards (you can just unplug the PSU connections) and consolidate into other cases as you lose more. Yes, this will void the warranty, but it's frankly worthless. Try to use it and you'll see.