Heathkit SB-104 - Page 116

J
Driver Circuit Board
TROUBLESHOOTING CHART 1
NOTE: Heath part numbers that correspond to the circuit
component numbers will be found in the Parts List starting
on Page 91 of this Manual.
SYMPTOM
Low output.
ALC inoperative.
.............................................................. 7
I 0901 DRIVER CIRCUIT BOARD
I
I
I
I
I
I
POSSIBLE CAUSE
1. 13.8V mlssbng.
2. Q901, 0902.
3. L901, L902.
4. D903. D904.
-
1. Low lnput from TX
I Flpredriver (board C).
2. D905, D906.
3. Poor load impedance.
+13.BY
acc LOW HI
ON ON
SCHEMATIC
CIRCUIT BOARD J
DIODES
D901, D902
D903. 0904
D905, D906
v
TRANSISTORS
Q901,Q902 I 2 PT6619 I 417-830
, -
QUAN-
TITY
2
2
2
TYPE
1
N4W2
DRS-110
IN191
HEATH
PART NO.
57-65
57-64
56-26