Amiga 1000 - Power Supply Test

AMIGA
1000 ASSEMBLY
LEVEL REPAIR
1.4
POWER SUPPLY
TEST
1.4.1
Remove
the TOP
COVER
and SHIELD
from
the
computer.
•
Refer to
SECTION 2,
COMPUTER
DISASSEMBLY,
Steps 2.3
and
2.4.
1 .4.2
Using an
oscilloscope,
measure the
following
signals
at
the
power supply
connector, J14:
A. pin
1
—
Purple Lead
—
CnnctJ14
—
Should
=
-5
VDC
B.
Pin
2
-
Orange Lead
-
CnnctJ14
—
Should
= +12
VDC
C.
Pin
3,4
—
Black
Leads
-
CnnctJ14
—
Should
= Sys
GND
D. Pin 5,6
-
Red Leads
-
CnnctJ14
—
Should
=
+5
VDC
E.
pi n
7
_
Gray Lead
-
Cnnct
J14
-
Should
=
60
Hz
/ 50
Hz
•
tf ALL readings
are CORRECT,
continue
to 1.5
VIDEO
OUTPUT
CHECK.
•
If ANY
readings
are
INCORRECT, continue to
Step
1.4.3
below.
1.4.3
Unplug
connector J14
from the
PCB and
measure the molex
connector.
A.
pin
1
—
Purple
Lead
-
Cnnct J1
4
—
Should
=
-5 VDC
B.
Pin
2
-
Orange Lead
-
Cnnct
J1 4
-
Should
=
+12
VDC
C.
Pin
3-4
-
Black
Leads
-
Cnnct
J14
-
Should
=
Sys
GND
D.
Pin
5-6
—
Red
Leads
—
Cnnct J1 4
—
Should = +5
VDC
E.
Pin
7
-
Gray
Lead
- Cnnct J1
4
-
Should = 60
Hz /5oHz
•
if ALL
readings
are
CORRECT,
continue
to
Step
1.4.4
below.
•
If
ANY readings
are
INCORRECT,
REPLACE the
power
supply.
Refer to SECTION 2,
COMPUTER
DISASSEMBLY,
Steps 2.5,
2.6,
2.7.
1.4.4
Plug connector J14
into
the
PCB and
unplug
connector
J
13.
Measure
at
connector J14.
A.
Pin
1
-
Purple
Lead
-
Cnnct
J1
4
-
Should
=
-5
VDC
B. Pin
2
—
Orange Lead
—
Cnnct
J1 4
—
Should
= +12
VDC
C.
Pin
3-4
—
Black Leads
-
Cnnct J1 4
—
Should
=
Sys
GND
D. Pin
5-6
-
Red Leads
-
Cnnct
J1
4
-
Should - +5
VDC
E> pin
7
_
Gray Lead
-
Cnnct J14
-
Should
=
60
Hz
(50
Mz
•
if
ALL readings
are
CORRECT,
REPLACE the
DRIVE
MECHANISM.
Refer to
SECTION 2,
COMPUTER
DISASSEMBLY,
Step
2.5.
•
If ANY
readings are
INCORRECT,
REPLACE the
POWER
SUPPLY.
Refer
to
SECTION 2,
COMPUTER
DISASSEMBLY,
Steps 2.5,
2.6
and
2.7.
1-4