Commodore AMIGA Technical Manual page 7

AM IGA 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 SU PPLY T E S T
A. Pin 1
— Purple Lead — C n n ctJ14 — 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 J 1 4 — 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 J 1 4 — 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 J 1 4 — 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 J 1 4 into the PCB and unplug connector J13. Measure at connector J14.
A. Pin 1 — Purple Lead — Cnnct J 1 4 — Should = - 5 VDC
B. Pin 2 — Orange Lead — Cnnct J 1 4 — Should =
+ 12 VDC
C. Pin 3-4 — Black Leads — Cnnct J 1 4 — Should = Sys GND
D. Pin 5-6
— Red Leads
— Cnnct J 1 4 — Should = + 5 VDC
E. Pin 7
— Gray Lead
— Cnnct J 1 4 — 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