Keysight Infiniium 8000 Series, Service Manual

Page: 84 / 162

Chapter 5: Troubleshooting
Power Supply Trouble Isolation
84
Figure 5-7
Power Supply Voltage Test Locations (A13)
Table 5-8 Power Supply Voltage Limits
B
Turn off the power and measure the power supply resistances to ground to
check for shorted supply lines.
You can probe the test points on A13, shown in See Figure 5- 7, for this resistance check.
C
Replace any shorted assembly.
You can locate the shorted assembly by disconnecting assemblies from the power supply,
one at a time.
D
Replace the power supply.
1 If there are no shorted assemblies, but the power supply will not power up
correctly, replace the power supply. See Chapter 6, “Replacing Assemblies,” for
an explanation of how to remove and replace the power supply.
2 Re- assemble the oscilloscope and apply power.
E
Check for the oscilloscope display on screen.
1 You should see the oscilloscope display (See Figure 5- 2). If not, see “No Display
Trouble Isolation” on page 79.
2 If you see the display, return to the Primary Trouble Isolation Flowchart.
Supply Voltage Specification Limits
+5.1 V
±
0.1 V +5.0 V to +5.2 V
-5.2 V
±
0.1 V -5.1 V to -5.3 V
+12.1 V
±
0.3 V +11.8 V to +12.4 V
-12.1 V
±
0.3 V -11.8 V to -12.4 V
+3.3 V
±
0.1 V +3.2 V to + 3.4 V
Reconnect Assemblies and Cables
Reconnect all assemblies after testing. The oscilloscope must have all cables connected for correct power up.