PackEye Reseat FHT 681 Connections

Press and hold the power button for approximately 10 seconds until indicator lights are off.

Shoulder straps should be facing down.

Slowly slide foam assembly out of backpack to access FHT 681 amplifier. This process might take two people; one to pull the backpack and the other to pull the foam assembly.

The gamma detector is connected to the FHT 681 amplifier at PMT1. Push toward connection, turn coupling nut counterclockwise, and pull away from connection.

Use small, slotted screwdriver.

The neutron detector connections will be accessible.

There are two (2) neutron detectors. Unscrew collar counterclockwise. Pull connector away from detector.

There are two (2) hook and loop (Velcro) strips attaching the power supply module to the FHT 681 amplifier. If necessary, use a large, slotted screwdriver to pry the FHT 681 amplifier away from the power supply module.

Use small Phillips (PH1) screwdriver. Retain screws.

Use a 5-mm nut driver or small needle nose pliers.

Ribbon cable is still attached internally. Pull panel until ribbon cable is accessible.

Use small Phillips (PH1) screwdriver. Retain screws.

It is recommended to mark the location with a permanent marker.

Check that the two (2) neutron detector and one (1) gamma cable connector grounding nuts are tight and do not rotate. Tighten with pliers, if required.

Disconnect and reconnect ribbon cable several times to remove oxidation. Verify connection is secure.

Align circuit board with fourth slot from bottom of enclosure and slide into place. Verify face plate aligns with housing.

Verify gasket is aligned between housing and end panel before inserting screws.

Use small Phillips (PH1) screwdriver. Attach each screw loosely until all are inserted and then tighten. Verify these screws are tight to minimize electrical interference.

Verify gasket is aligned between housing and end panel before inserting screws.

Align serial port openings with internal serial port connectors.

Attach each screw loosely until all are inserted and then tighten. Use 5-mm nut driver.

Use small Phillips (PH1) screwdriver. Attach each screw loosely until all are inserted and then tighten. Verify these screws are tight to minimize electrical interference.

A significant force might be required to rejoin the components. A snap should be heard when they are successfully reconnected.

There are two (2) neutron detectors. Push connector onto detector. Turn collar clockwise. Hand-tighten the collar.

Use small, slotted screwdriver.

The gamma detector is connected at the FHT 681 amplifier at the connection labeled PMT1. Disconnect and reconnect both connections to the 90-degree elbow several times to remove oxidation.

Slide the protective foam assembly into backpack

Record observations, times, and results for the maintenance report.

As specified by management or contractual obligations.