Quote from: BFL-Engineer on May 19, 2012, 01:43:55 PM

It seems one of your units is throttling. There are two ways to know whats happening

1) Verify the Heatsink is firmly attached.
2) Try a lower bitstream like 800 or 768, etc. If the hash-rate increased, it means the unit was throttling.

It is odd that the unit throttles if your room temperature is 22C up to 25C and the units are not taking
exhaust air from another hot component (PC or PSU, etc). They are specifically tested for this situation
prior to shipping.

You can also verify the Silicon Paste under the heatsinks (if you have the utility to do so).

Please let us know how it goes. You can post or send PM.

Regards,
BF Labs Inc.

Room is temperature controlled and sits between 68-70F (20-22C). There is nothing exhausting hot air and the singles sit about 8 inches apart and should be well vemtilated. I have tried power supply, usb cables, host ports from working units and no change in operation.

I had a box of 3 and a box of 2, just wondering if both units I have issues with were from the box of two. At least from appearance, no damage to either packaging.

I have tried the 832 and 800 firmware, both exhibit the same behavior in cgminer (after a minute or so, stuck at 600 +- 100). I did a Light Diagnostic in easyminer at 832, Throttled 22 time before reaching 100 in about 600 seconds.

All the square heatsinks appear firmly in place as well as the small heatsink/fan on the botton, I don't want to put any pressure to them. The main heatpipe had both clips seated correctly and I can see white thermal paste along the edges of the chips. It also appears flat and not out of place. Verified the top and bottom fans are both operational. Top fan seems to be pushing the same as the other units, tested by checking deflection of a piece of paper over top vent. I tried putting a powered 80mm fan on the button pushing into the unit, still problematic.

I have the ability as well as the usual white thermal paste. But I will save removing the heat pipe, cleaning and reapplying as a last resort.

edit 1) I am now trying the 768 firmware to see what happens, figure 768 is better than 600 or below.

edit 2) 768 firmware seemed solid, could not detect any throttling, ran at 45C for 2 hours with hm/s avg 754/762. Tried the 792 firmware, ran at 127-200mh/s at 37C. Downloaded and flashed it twice to make sure the flash wasn't bad. Gave up on 792. Now trying 800 firmware. Will post results after a few hours.