Technical data

90 4000 X-Series Oscilloscopes Service Guide
4 Troubleshooting
5 Next, check the supplies coming from the system board:
Test Point
(near J3700)
Expected Value Assemblies
Supplied
If Good If Bad
VP5V (+5V) +5 V ±3% Keyboard,
System Board
Indicates supply coming from
system board is good.
Replace the system board.
VP12V (+12V) +12 V ±3% System Board Replace the system board.
VP1V8
(+1.8V)
+1.8 V ±3% System Board Replace the system board.
VP1V4
(+1.4V)
+1.4 V ±3% System Board Replace the system board.
VP1V (+1V) +1 V ±3% System Board Replace the system board.
VP1V2
(+1.2V)
+1.2 V ±3% System Board Replace the system board.
VP2V5
(+2.5V)
+2.5 V ±3% System Board Replace the system board.
VP3V3
(+3.3V)
+3.3 V ±3% LCD, System
Board
Go to “To check the display
supplies” on page 95.
VM12V -11.5 V to
-12.5 V
System Board Replace the system board.
VM14V -13.5 V to
-14.5 V
System Board Replace the system board.
VM8V -7.814 V to
-8.333 V
System Board Replace the system board.
VM5V2 -5.023 V to
-5.329 V
System Board Replace the system board.
VP13VF +13 V ±3% System Board Replace the system board.
VP25V
(BL SUPPLY)
+24.84 V to
+25.2 V
Display
Backlight
Power
Go to “To check the display
supplies” on page 95.
VP13V_PRB
(+13V_PRB)
+13 V ±3% AutoProbe
Interface
Go to “To check the keyboard
supplies” on page 96.