Specifications

SYMPTOM
Amplifier causes power line fuse
to blow. Power Iine fuse blows
a-
gain with V6 out of socket.
Amplifier causes power line fuse
to blow. Power line fuse does not
blow again with V6
out of socket.
Any or all tube filaments not lit.
DC voltage at V6 cathode (pin 9)
is incorrect as specified below.
a) No
voltage
b) High voltage.
c) Low voltage.
Excessive hum on mag. phono
or tope
head.
Excessive noise on mag.phono
and
tape head
Sustained
oscillations.
Sustained microphonics on mag.
phono 'and
tape head.
Hum on all inputs
TROUBLE-SHOOTING CHART
CAUS E
Line
cord, J6, primary or high voltage
secondary windings of T2 shorted internally
or externally (wiring).
V6, C17, V4, V5, or T1 primary shorted
internally or externally.
Open lead from 6.3V winding of T2.
6.3V winding of T2 open.
Defective V6
C17 shorted
internally or externally.
Connection from C17 to pin 9 of V6 broken.
Connection
to center tap of h. v , secondary
winding of
T2 open.
Output tubes V4 & V5 over-biased or not
drawing
current.
Excessive current drain in amplifier.
Defective V6
Vl
defective
Fil. leads dressed too close to grid lead.
Tube shield not making electrical contact
to base or base not making electrical con-
tact to chassis.
Shielding and grounding of wiring to input
jacks not
exoctly as instructed and shown
in drawings.
V1 socket and
contacts dirty.
poor dress of output transformer T1 leads
Vl
defective.
V2 defective, not properly shielded, or
dirty sockets and
contacts.
Dress of power transformer 12 leads.
7
REM ED Y
Replace or repair.
Replace or repair.
Repair
Replace
Replace
Replace or
repair.
Repair
Repair
See trouble-shooting typical tube
stage.
See trouble-shooting typical tube
stage.
Replace
Replace
Dress fiI. leads away from grid lead.
Check and
correct
Correct
Clean throughly with carbon
tetrachloride.
Dress all input leads and T1 leads
away. from
each other. Keep T1
leads away from input lacks.
Replace
Replace,
correct, or clean.
Correct