Juma Clone Amp failures

[Russ Collins]

I have had a Juma Clone amp for several months.  Shortly after I bought it, it suddenly had a low power output, around 60 Watts maximum with a 5 Watt drive.   I determined it was a bad power transistor and ordered two transistors from China and replaced both of them.  It worked great, about 150 Watts output with 5 Watts drive on 20 and 40.  About a week later it failed again with the same symptoms.  This time I noticed that the copper land for the emitter of one of the transistors was not connected to anything!  Looking closer, it seems that the land was never on the board.  See the info below.  I don't know how or why it was this way,  but it has been performing up to specs with the third set of transistors for some time now.