Attenuator Sweep Circuit Board

To remove the Attenuator/Sweep circuit board, perform the following steps:

1. Use a 1 /16-inch Allen wrench to loosen the set screws in the following knobs and remove the knobs: CH 1 and CH 2 VOLTS/DIV Variable, SEC/DIV Variable, and SEC/DIV. Note the position of the SEC/DIV knob for reinstallation reference.

2. Set the CH 1 and CH 2 VOLTS/DIV switches to the same position; then remove their knobs by pulling straight out from the front panel. Note switch positions for reinstallation reference.

3. Use a 9/16-inch nut driver to remove the nuts securing the VOLTS/DIV switches to the front panel.

4. Disconnect the following connectors from the Attenuator/Sweep circuit board:

a. P1011, a four-wire connector located behind the CH 1 VOLTS/DIV switch assembly.

b. P2011, a four-wire connector located behind the CH 2 VOLTS/DIV switch assembly.

c. P7000, a seven-wire connector located on the rear edge of the circuit board.

d. P6000, a ten-wire connector located on the right edge of the circuit board.

5. Remove three screws which secure the shield to the Main circuit board (located on the bottom of the Main circuit board).

6. Loosen but do not remove two screws securing the front of the shield to a bracket on the front panel. These screws are accessible from the bottom of the instrument through two holes along the front of the Main circuit board.

7. Pull the Attenuator/Sweep circuit board and shield assembly straight back from the front of the instrument until the circuit board interconnecting pins are disengaged and the switch shafts are clear of the holes in the Front-Panel circuit board. Then lift out the entire assembly through the top of the instrument.

8. If accessibility to the bottom of the Attenuator/ Sweep circuit board is desired, remove three screws located at three corners of the circuit board and two screws from the bottom of the shield and separate the shield from the circuit board.

To reinstall the Attenuator/Sweep circuit board, perform the following steps:

9. If the shield has been removed, secure it to the Attenuator/Sweep circuit board using three screws (removed in step 8). Insert two screws in the bottom of the shield at the front edge (removed in step 8), but do not tighten them.

10. Insert the three switch shafts through the holes in the Front-Panel circuit board and the front panel. Carefully align the 10 interconnecting pins on the Front-Panel circuit board with their corresponding connectors on the Attenuator/Sweep circuit board. Push the board forward into position, ensuring that the two screws in the bottom shield engage the front-panel bracket.

11. Tighten two screws securing the shield to the frontpanel bracket (loosened in step 6).

12. Reinstall three screws securing the shield to the Main circuit board (removed in step 5). Then tighten the two screws installed at the front edge of the shield in step 9.

13. Reconnect the four connectors to the Attenuator/ Sweep circuit board that were disconnected in step 4.

14. Reinstall two 9/16-inch nuts securing the VOLTS/ DIV switch shafts to the front panel (removed in step 3).

15. Reinstall the two VOLTS/DIV knobs at the positions noted in step 2.

16. Reinstall the SEC/DIV knob onto its shaft at the setting noted in step 1 and tighten its set screws.

17. Rotate the three Variable control shafts fully clockwise to their calibrated detent positions.

18. Reinstall the Variable knobs onto their shafts (with the lettering horizontal and right-side up) and tighten their set screws.

0 0

Post a comment