On Mon, May 30, 2022 at 11:35 PM, Swiss wrote:
As far as checking Q502 in circuit, a diode check indicates that it is conducting, However its values are higher then that of Q501. Roughly from 1V to 1.5V. Whereas Q501 is .7 V drop. It's hard to say as the capacitors on their bases are charging up.
I can assure you: A steady-state voltage of approx. 10.5V (mind the polarity: Q502's emitter 10.5V more positive than its base, as may be concluded from 3) and 4)) between Q502's emitter and its base means its B-E-diode is non-existent.
- Perhaps the trace between the cathode of CR502 and the base of Q502 or some other connection is gone?
- Maybe there's an NPN transistor where a PNP should be at Q502?
The capacitors at the bases of Q501 and Q502 are negligible when measuring steady DC voltages.
Not sure what you mean by "However its values are higher then that of Q501. Roughly from 1V to 1.5V.". 1V or even 1.5V across a healthy B-E junction of Q502 is wrong; it should be near 0.7V max.
Raymond
