Agilent Technologies 54835A, 45A, 46A manual Re-assemble the instrument, Troubleshooting Procedure

Chapter 5: Troubleshooting

To check the keyboard

Troubleshooting Procedure

Use this procedure only if you encounter key failures in the keyboard test procedure. If any knobs fail, replace the keyboard assembly.

1Disconnect the power cord and remove the cover.

2 Remove the front panel assembly.

See chapter 6 for instructions.

3Remove the keyboard assembly and the cursor keyboard assembly from the front panel assembly. Partially re-assemble the front panel assembly, including the flat-panel display and lens, but omitting the keyboard and cursor keyboard. Re-attach the partial assembly to the chassis.

Be sure to reconnect the display video cable and the backlight inverter cables. See chapter 6 for instructions on removing and disassembling the front panel.

4Separate the elastomeric keypads from the cursor keyboard and keyboard assemblies.

CAUTION	CONTAMINATION CAN CAUSE INTERMITTENT OPERATION!
	Be careful not to contaminate the key side of the PC board or the keypads. Dust and fingerprints
	on these parts may cause intermittent key operation.

5Set the cursor keyboard and keyboard assembly on an antistatic electrical insulated surface.

6Connect the cursor keyboard cable to the keyboard assembly. Connect the keyboard cable to the scope interface board in the chassis.

You may need to set the chassis on its side to allow proper routing of the cables without straining them.

7Reconnect the power cable and apply power.

8Enable the graphical interface, then start the keyboard test as described in the previous procedure.

9Carefully short the PC board trace, with a paper clip or screwdriver, at each nonoperating key (as determined by keyboard test), and look for an appropriate response on the display.

•If the display responds as though a key were pressed, replace the elastomeric keypad.

•If the display does not respond as though a key were pressed, replace the keyboard.

10 Re-assemble the instrument.

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