Technical data

78 7000 Series Oscilloscopes Service Guide
4 Troubleshooting
To check the 7000A Series system board
1 Remove the handle, tilt legs, and cabinet.
2 Check that all cable connections are securely connected from
the system board to:
• Power supply
• Keyboard (7000A Series only)
• Display (7000A Series only)
• Inverter board (7000A Series only)
• Fan
3 Verify the voltages at the system board test points listed in
the table below. Refer to Figure 12 on page 75 and Figure 13
on page 76to locate the test points.
Table 13 Regulator Voltage Test Points
4 If the voltage at test point L3301 and/or L3302 is not within
the specified range, replace the system board.
5 If the voltage at test point L3204 and/or L3201 is not correct:
• Disconnect J2730 from the system board and measure
pins 1 and 2 on the system board connector. This is the
voltage to the display, and it should be 3.3V. If it is not,
replace the system board. If the voltage is correct, replace
the display.
• Disconnect J2750 from the system board and measure
pins 1, 2, and 3. This is the voltage to the inverter, and it
should be 12.4 V. If it is not, replace the system board. If
the voltage is correct, replace the display.
Test point Voltage Output from
regulator:
L3204 3.3 (+- 0.1) U3202
L3201 5.0 (+- 0.1) U3202
L3301 1.5 (+- 0.1) U3300
L3302 -5.2 (+- 0.1) U3301
7000 service guide.book Page 78 Thursday, October 16, 2008 12:18 PM