Need to say, just installed the fixed Chromed box with the NOS MJ10012 transistor and worked, but stalled couple of times.

the next deal on these boxes and MOSTLY SURE the REAL cause of the premature ( bad quality ) transistors failure is the POOR ground between Box housing and printed circuit board. A friend of mine got fixed TWO orange boxes just cutting the backing where the ground solds to the PCB, and solded a wire to get the PCB DIRECTLY GROUNDED with a wire. He is in fact running at this moment an orange box ( what began to stall quite often ) with a wire attached here, and grounded STRAIGHT to firewall