Technical data

64 User’s and Service Guide
87050A Option K22 Troubleshooting and Block Diagram
Front Panel Board
Turn the instrument power on and verify the following:
• Verify the condition of each of the switching paths by issuing commands to switch
each of the paths to either the transmission or reflection path. Ensure that the LCD
indicates the appropriate path.
• If the LCD indicates a wrong path, the problem can lie with either the front panel
board or the main switch board. Measure the RF path to determine where the
problem is.
• Ensure that the front panel washers between the board and front panel assembly are
present. Missing washers can cause erratic LCD behavior.
• If the LCD does not display the proper path, verify that the RF path has indeed been
switched. If the problem lies with the front panel board, replace it.
Controller and Switch Driver Boards
Turn the instrument power on. Verify the condition of each of the switching paths by
issuing commands to switch each of the paths to either the A i/p 2 or B i/p 2 path. Verify
each of the RF paths for connection. If an RF path is not connected to the necessary port or
terminated in 50 Ω, replace the controller and switch driver board.