Guru
Joined: 12/08/2011
Location: AustraliaPosts: 357
| Posted: 05:42am 17 Jan 2023 |
Hi All
After checking every Transistor, now none of them show a low resistance between E & C.
Typically they are higher than 10k Ohm.
So started taking voltages as per your suggestion.
Some voltages that I am trying to get my head around.
Rails are higher then marked +33v and -32.6v
Bad board Good Board
C17 + = -0.103v couldn's reach it
CR9 = -9.6v -9.5v
Q8 C = -10.3 +1.482
Q2 B = -10.16 +0.825
Q1 B = -10.78 -0.744
Q3 B = -9.56 +0.014
Q4 B = -10.03 +0.016
Q4 C = -2.54 +3.2
R13 = -21.8 -16
-10.8 -0.744 Top of C6
R19 = -10.29 +1.482 (same as Q8 C)
R20 = -10.16 +0.31
T10 = -10.16 +0.015
Drop
across
Z1 = 0.3v 0.682v
Without turning a live board over, some of the measurements
are doubtful on which side of the Resistor it belongs.
R19 a case in point when compared to Q8 Collector.
EDIT: You were right again.
Taking both boards onto the bench and using a current limited PS, i connected 5vdc to top of diode pack. Both boards drew 199mA and dropped the voltage to 2.5v.
Edited 2023-01-17 15:58 by Dinosaur