Sadly almost exactly 4 months from time of purchase, machine will no longer boot.  No display output.  Single post beep, 10 seconds later, the machine resets and does the same thing (stuck in a loop).  Tried resetting CMOS, then replacing CMOS battery, tried different memory, and combinations, etc.  No way to get any output.  Understand the risks of refurbs with only 3 month warranty.