Eberline ESP-1 - Page 66

€.
Repairing
the
Low-Voltage
Supply
(1)
У.
low
Check
for
excessive
current
drain.
Isolate
to
faulty
component
by
removing
one
IC
at
a
time
until
fault
is
found.
Next,
try
to
adjust
for
5.00
volts.
If
the
adjustment
is
satisfactory,
use;
If
adjustment
fails,
A101
is
inoperative.
Replace
it
and
readjust
V,
for
5.00
volts.
(2) V, high.
Try
to
readjust
for
5.00
volts.
If
the
adjustment
is
satisfactory,
use.
If
adjustment
fails,
replace
A101
and
readjust
V,
for
5.00
volts.
(3)
Error
in
+V.
Probable
causes:
(a)
QIOI
defective.
(b
PWR
ON
from
computer
0.4
volts.
(4)
Error
in
Vaa.
Probable
causes:
(а)
0102
defective.
(b)
013
defective.
Also
check
010
and
C10.
(5)
Error
in
V,.
Probable
causes:
(a)
A11
inoperative.
(b)
C15,
C14
defective.
(c)
V,
adjust,
(R18)
defective.
f.
Speaker
nonfunctioning
(Note:
Check
S-RATE
[S10]
for
proper
setting.)
Probable
causes:
(1)
Speaker
defective.
(2
ОП,
012
defective.
(3)
A104
inoperative.
(4)
S10
defective.
(5)
CRIOI
defective.
(6)
SPKR
from
computer
»0.4
volt
with
speaker
ON.
Check
ribbon
cable,
contact
at
pin
8
of
Al,
and
board
damage.
If
they
are
satisfactory,
Al
or
keypad
switch
is
defective.
ESP1.MAN/February
1992
S-17