Hi Lee
regulated voltage age steady at 15 and 14.6 on low voltage setting 76 volt rail
yes I have those but first I switched with an other ready to go and tested good 3403 and still same. Checked and supply voltage to the veri resistor low and fluctuating. Poked around and did not find anything obvious resistors in that path in spec. Cleaned flux from a few solder connects. No change. Tested two diodes d106 and d 107 with ohm meter on diode test. Fired up and now voltage is up and bias is down.
Will let run for a while to warm up.
15 minutes no change all steady. I will heat a few joints to make sure the solder is correct.
25 minutes gone and bias up to .550 again on right.
Turned both resistor pots to minimum and max - voltages are similar on both sides. Base voltage is similar on left and right both at low and high pot setting.
Both 3403 are 77' F
Base voltage on q105 and q101 are the same.
Collector voltage Q106 .100 mv lower on right in Min bias setting and equal in high bias setting.
Protection circuit?????