Technical data
80 7000 Series Oscilloscopes Service Guide 
4 Troubleshooting
To check the fan
The fan speed is controlled by a circuit on the system board. 
1 If the fan is running, perform the internal self-tests. Go to “To 
run the internal self-tests” on page 81.
2 If the fan is not running, it may be defective. Follow these 
steps:
a Disconnect the fan cable from the system board. 
b Measure the fan voltage at the connector on the system 
board. 
See the figure below for the location of the fan connector. 
c If the fan voltage is approximately +8.5 Vdc at room 
temperature, replace the fan. If the fan voltage is not 
approximately +8.5 Vdc, replace the system board. 
The proper voltage range depending on temperature is 
between +6.0 Vdc to +11.5 Vdc.
Figure 14 Location of the Fan Connector
Fan 
Connector 
J3400
7000 service guide.book Page 80 Thursday, October 16, 2008 12:18 PM










