2 things to try:

• adjusting the voltage knob on the stick
• underclocking the stick

I had a 2pac that I had to underclock.  I found that it was stable for about a week with "--gekko-2pac-freq 45"  after a while that week turned into a few days, then a few hours.  I went as far down as "--gekko-2pac-freq 25" to try to reach some stability, which helped for a while, but it doesn't last long anymore, so i took it out of service.  but i got months of underclocked hashing power instead of 0 hash from that stick.

Anywho, an example of the command i used for that:


yes, the "--suggest-diff 1" is not a typo.  The pool will kick it up to a difficulty of 3 after a few minutes when running at 25.
Also, concerning "--gekko-serial "GS-10019785" ", the hyphen replaces the D of GSD.  D refers to the 2pac, C for the Compac, H for the Newpac, etc.     Wont find any sticks otherwise, from what i can tell.  Also, change the serial number to yours, of course!
but using the serial number is great, as you can run a separate cgminer instance.  Just start it first so it gets locked out of the 2nd cgminer instance.

If you really want to play around with underclocking and finding that sweet spot, check this out:


This sets our maximum frequency to 100, but starts at 25. after an hour (3600 seconds), it will jump up to the next supported frequency (its like 6.25 or  something, if i remember correctly) by rounding the 1 from "--gekko-step-freq 1" up to that minimum.  Anyways, so for hour 1, it runs at 25, then for hour 2 it runs at 31.25, hour 3 at 37.5, hour 4 at 43.75, hour 5 at 50, ..., hour 9 at 93.75, and hour 10 and beyond at 100.  play with the values as you see fit.  i recommend logging it to a file so you can see when it failed.

I need to play with the voltage settings on my bad stick, so i haven't tossed it yet - maybe my voltage is just too high and needs to come down.  I just haven't had the chance to really play with it.