Power Supply Test - Amiga 1000 Assembly And Repair Instructions

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> pi
n 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