Quote from: helipotte on October 15, 2014, 10:03:48 PM

Check your cooling and power. These tubes are VERY sensitive to this. in my opinion one fan is insufficient. Also try 260Mhz. Can actually be faster that 270 if you have iffy

chips.

These tubes need a solid 225-250w of clean power per board to be trouble free.

You need 20% overhead per board or they will try to draw what isn't there and end up in a bad state. A 1200 watt power supply is barely enough but a good one (Thermaltake Gold 80+) works just dandy. Alternatively 2x of the Thermaltake 750 Bronze Smart paired up gives you more power per board at less cost and works great also.

Please see my other posts on how my 32 boards run over 100% @ 300 Mhz continuously despite ambient air temperature upwards of 40C. Cool

http://s14.postimg.org/mku0rcizl/Screen_Shot_2014_10_29_at_11_48_30_PM.png