Instruction manual
VOLTAGE
AND
RESISTANCE
CHART
"'"
"H'
DC
VOlTS
DCVOUS
AC
VOLTS
(1kc)
"''''.-:I
NO
SIGNAL
l.4WAm
1.DVOLTS
INPUT
UNIT
OFf
-,-
I
".
'112
,.
...,
V,
2
•
•
I."
510KD
,
...
...
1.13
'.OKlI
.U
fJI-m
(6. aVN:
til
pin 9)
,
232
".
•.s
,_
7
112
105
"
...,
8
105
1112
•••
""'''
•
f11_nt
....
1
• •
•••
......
...
va
2
•
0
•••
-..
,
,~.
"
.,
'"''
.U
fll-'
(6.3VAC
b.twee)
•
7
'"
".
,
I
......
"
8
• •
'.S
......
•
,.,
'"
'"
•
..
118'
,
'"
.."
V'
2
a
,.,
'"
,-
.U
f11_t
(6.3VAC
be'--)
•
7
'"
..
"
8
•
All
~
CIIIcl_btane:
__
........ntdto
d-II.
Vo","-
_--'
....
CI
hIth
InpIt
1....0-
vrvM.
All
...
1,
__
F
...
_
.....
w,1ta
pill 3 of !hi
EZ81
graunOM
-.pt,
of
-,
wMn
tM
~
to
__
..
pint 2
..
8 of the
EZ81
II
bel",
checW,
0,-.
....
11
..
vol,.
.......
".1
...
""
Is 117yoltlN::,'CI
..
HOl'EIALL
YQl.TAOI!
&
RESISTANCE
VAWI!S
MAYVAW NOIMALLYrv
.1,..
SYMPTOM
House
power line fuse blows;
fuse, F1, remains IntQct.
Fuse,
Fl,
blows.
Any or all tube
ftlc:zments
not lit.
DC
voltage at V4 cathode (pin 3)
is
incorrect os specified below.
a) No voltage
b) High voltage
c)
Low
'10 Itage
TROUBLE.SHOOTING
CHART
CAUSE
Short in line cord, J2,
J3
or associated
equipment plugged
Into
J2
or
J3.
If the amplifier causes a replacement fuse to
blow with rectifier tube VJ,removed, primary
or high voltage secondary windings
of
12
are
Incorrectly wired or shorted.
If Fl
does
not blow after replacement (with
V4 removed),
check
for short in
11+
circuih,
defective V4 and
ca.
Open lead
from
6.3
V winding of 12.
6. 3V winding of
12
open
Defectiye
VA
C8 shorted internally or externally.
Connection to C8 broken.
Connection
to center tap of h. v, sec. winding
of T2 open.
Output tubes V2 and V3 over-biased
or not drawing current.
Excessive current drain in amplifier.
Defective V4.
REMEDY
Ropcolr
Check
and
repair or replace.
Repair
Rapl
...
T2.
Replace
Replace or repair.
Repair
Repair
See trouble-shootlng
typieal
stage.
See
trouble-shooting typical
stoge.
Replace