Apple power mac g4 digital audio User Manual

							 
 TroubleshootingGeneral/Power Supply Verification  -   2 3 
1. Plug in a known-good power cord into the back of the com-
puter. Do not turn on the computer. 
2. Power Mac G4 (AGP or PCI) (see Figure 1): 
Connect the black lead of the volt meter to pin 16 of the 20-
pin power supply connector. Connect the red lead of the volt 
meter to pin 9 of the power supply connector. The volt meter 
should measure approximately +5V.
If you do not get a reading of +5V, re-check the volt meter 
connections and measure the voltage again. If voltage is still 
not present, replace the power supply; otherwise, go to the 
step 4.
If you do measure +5V on pin 9, the power supply is likely OK. 
Go to the next step for further verification. 
						

							 
 TroubleshootingGeneral/Power Supply Verification  -   2 4 
  
Figure 1. Power Supply 20-Pin Connector
Pin 20	+5V
Pin 19	+5V
Pin 18	GND
Pin 17	GND
Pin 16	GND
Pin 15	GND
Pin 14	[Power On]
Pin 13	GND
Pin 12	-12V
Pin 11	+3.3V +12V	Pin 10
+5V TRKL	Pin 9
POK	Pin 8
GND	 Pin 7
+5V Pin 6
GND	 Pin 5
+5V	Pin 4
GND	 Pin 3
+3.3V Pin 2
+3.3V	Pin 1 
						

							 
 TroubleshootingGeneral/Power Supply Verification  -   2 5 
3. Power Mac G4 (Gigabit Ethernet/Digital Audio) (see Figure 
2):
Connect the black lead of the volt meter to pin 11 of the 22-
pin power supply connector. Connect the red lead of the volt 
meter to pin 22 of the power supply connector. The volt meter 
should measure approximately +28V.
If you do not get a reading of +28V, re-check the volt meter 
connections and measure the voltage again. If voltage is still 
not present, replace the power supply; otherwise, go to the 
next step.
If you do measure +28V on pin 22, the power supply is likely 
OK. Go to the next step for further verification. 
						

							 
 TroubleshootingGeneral/Power Supply Verification  -   2 6 
  
Figure 2. Power Supply 22-Pin Connector
Pin 22	+28V TRKL
Pin 21	+5V
Pin 20	+5V
Pin 19	GND
Pin 18	GND
Pin 17	GND
Pin 16	GND
Pin 15	[Power On]
Pin 14	GND
Pin 13	-12V
Pin 12	+3.3V GND	 Pin 11
+12V	Pin 10
NC	Pin 9
+3.3V	Pin 8
GND	 Pin 7
+5V Pin 6
GND	 Pin 5
+5V	Pin 4
GND	 Pin 3
+3.3V Pin 2
+3.3V	Pin 1 
						

							 
 TroubleshootingGeneral/Power Supply Verification  -   2 7 
4. Power Mac G4 (QuickSilver/QuickSilver 2002) 
(see Figure 3):
Connect the black lead of the volt meter to pin 11 of the 22-
pin power supply connector. Connect the red lead of the volt 
meter to pin 22 of the power supply connector. The volt meter 
should measure approximately +25V.
If you do not get a reading of +25V, re-check the volt meter 
connections and measure the voltage again. If voltage is still 
not present, replace the power supply; otherwise, go to the 
next step.
If you do measure +25V on pin 22, the power supply is likely 
OK. Go to the next step for further verification. 
						

							 
 TroubleshootingGeneral/Power Supply Verification  -   2 8 
  
Figure 3. Power Supply 22-Pin Connector and 4-Pin Connector
Note:  
The four-pin connector (P4) supplies power to the 
multiprocessor.
Pin 22	+25V TRKL
Pin 21	+5V
Pin 20	+5V
Pin 19	GND
Pin 18	GND
Pin 17	GND
Pin 16	GND
Pin 15	[Power On]
Pin 14	GND
Pin 13	-12V
Pin 12	+3.3V GND	 Pin 11
+12V	Pin 10
+25V	Pin 9
+3.3V	Pin 8
GND	 Pin 7
+5V Pin 6
GND	 Pin 5
+5V	Pin 4
GND	 Pin 3
+3.3V Pin 2
+3.3V	Pin 1
+12V	Pin 1 +12V Pin 2
COM	  Pin 3COM	  Pin 4 
						

							 
 TroubleshootingGeneral/Power Supply Verification  -   3 0 
not present, replace the power supply; otherwise, go to the 
next step.
8. Connect the black lead of the volt meter to pin 16 of the power 
supply connector for AGP and PCI models or pin 11 for Gigabit 
Ethernet/DIgital Audio/QuickSilver/QuickSilver 2002 mod-
els. Connect the red lead of the volt meter to pin 4 of the power 
supply connector. The volt meter should measure approxi-
mately +5V.
If you do not get a reading of +5V, re-check the volt meter 
connections and measure the voltage again. If voltage is still 
not present, replace the power supply; otherwise, go to the 
next step.
9. Measure the voltage of pin 10 on the power supply connector. 
The voltage should measure approximately +12V.
If you do not get a reading of +12V, re-check the volt meter  
						

							 
 TroubleshootingGeneral/Power Supply Verification  -   3 1 
connections and measure the voltage again. If voltage is still 
not present, replace the power supply; otherwise, go to the 
next step.
1 0 . The testing is complete. You have just verified that the power 
supply is not the cause of the ÒNo apparent powerÓ symptom. 
						

							 
 TroubleshootingGeneral/SDRAM DIMMs -  3 2 
SDRAM DIMMs 
The Power Mac G4 uses the following types of SDRAM DIMMs: 
PCI/AGP/Gigabit Ethernet 
QuickSilvers/ 
Digital Audio 
PC-100 SDRAM PC-133 SDRAM
3.3 volt unbuffered 3.3 volt unbuffered
168-pin 168-pin
64-bit wide 64-bit wide
PC-100 DIMMs from recent Power Macintosh G3 computers are 
compatible with Power Mac G4 (PCI Graphics/AGP Graphics/
Gigabit Ethernet) computers; DIMMs in older Macintosh 
computers are not. Do not use older DIMMs even if they fit into the 
Power Mac G4 DIMM slots. Power Mac G4 (Digital Audio) 
computers must use PC-133 DIMMs, not PC-100 DIMMs.