Commodore Amiga - Page 7

AMIGA 1000 ASSEMBLY LEVEL REPAIR
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:
1.4 POWER SUPPLY TEST
A. Pin 1
— Purple Lead — CnnctJ14 — Should =
- 5 VDC
B. Pin 2
— Orange Lead — Cnnct J14 — Should =
+ 12 VDC
C.
Pin 3,4
— Black Leads —
Cnnct J14 —
Should =
Sys
GND
D. Pin 5,6
— Red Leads — Cnnct J14 — Should =
+ 5 VDC
E. Pin 7
— Gray Lead — Cnnct J14 — Should =
60
Hz
• If 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 J14 —
Should = - 5 VDC
B.
Pin 2
— Orange Lead — Cnnct J14 — Should =
+ 12 VDC
C. Pin 3-4
— Black Leads —
Cnnct J14 —
Should = Sys
GND
D.
Pin 5-6
— Red Leads —
Cnnct J14 —
Should = + 5 VDC
E.
Pin 7
— Gray Lead — Cnnct J14 —
Should =
60 Hz
• 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 J13. Measure at connector J14.
A. Pin 1
— Purple Lead —
Cnnct J14 —
Should = - 5 VDC
B. Pin 2
— Orange Lead —
Cnnct J14 —
Should =
+ 12 VDC
C.
Pin 3-4
— Black Leads —
Cnnct J14 —
Should = Sys
GND
D.
Pin 5-6
— Red Leads —
Cnnct J14 —
Should =
+ 5 VDC
E.
Pin 7
— Gray Lead —
Cnnct J14 — Should =
60
Hz
• 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