Picked up an 8663A labeled "Dead" on a flea market.
Not to expenceive and I was willing to risk the money.
The fault was located to the inverter where one of the inverter power transistors
along with a 22uF capacitor (15 in the chematics) was broken.
Luckily, I had a couple of BUX48 in my junk box with close enough specifications
compared to the two MJ16012 originally used. After replacing the capacitors,
changing the bleeder/balancing resistors to 18k the unit came back to life.
MJ12016 as well as BUX48 is obsolete since a long time. Anyone having
repaired this design using available bipolars and can share information
about what can be purchased today?
Cheers
Ulf Kylenfall
SM6GXV
