Filter
Top Products
Maintenance
THS710A, THS720A, THS730A & THS720P Service Manual
6–37
Use these techniques to troubleshoot other parts of the instrument.
Buttons. Press each of the front-panel buttons to verify that it operates properly.
The table below lists the buttons that depend on a particular instrument state for
you to see an effect when the button is pressed. Unless noted otherwise, the
instrument should be in scope mode for this test.
Button Precondition Expected Behavior
HARD COPY None With no connection to the
RS-232 port, a message
will appear approximately
10 seconds after HARD
COPY is pressed
Any bezel button Press DISPLAY first Displays pop-up menu
CLEAR MENU Press DISPLAY first Removes menu
SCOPE Press METER first Changes to scope mode
+
/– Rocker Press CURSOR and then
choose Function V Bars first
Cursor moves
TOGGLE Press CURSOR and then
choose Function V Bars first
Changes active cursor
WAVEFORM OFF Press CH 1 first Removes waveform
VERTICAL MENU Press CH 1 first Displays menu
VOLTS/DIV Press CH 1 first Changes sensitivity
VERTICAL POSITION Press CH 1 first Repositions waveform
TRIGGER LEVEL Press CH 1 first Changes trigger level
SET LEVEL TO 50% Adjust TRIGGER LEVEL first Resets trigger level
If any button fails to operate, inspect and/or clean the switch flex-circuit
assembly and the switch mat. If cleaning does not solve the problem, the switch
flex-circuit assembly, switch mat, or main board may be defective. Use the
procedure below to isolate the problem:
1. Replace the switch flex-circuit assembly and then retest the buttons. If the
problem persists, proceed to step 2.
2. Replace the switchmat and then retest the buttons. If the problem persists,
proceed to step 3.
3. Replace the main board.
Other Troubleshooting