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SB1008 - HH Button Shaft Replacement

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Some HH transmitters in early production runs were assembled with an adhesive connecting the pushbutton switch shaft and the switch actuator inside the transmitter. In most cases, the adhesive blocks a tactile feel of a “snap” or “click” when the switch is activated. If desired, the switch shaft can be replaced with a new part to enable a tactile feel.
This is what the assembly looks like inside, with and without the adhesive:

Adhesive1

NOTE:  If the switch action already has an acceptable tactile feel when it is operated, the procedure shown in this bulletin is not necessary.

Is This Modification Necessary?

A quick check can be made to see if the unit needs this modification without removing the circuit board assembly.
Remove the grommet that covers the switch using an “orange stick” or other non-marring tool.

OrangeStickTool

Hold the transmitter housing so the opening is facing downward. The button shaft will fall out if there is no adhesive, which means that the shaft does NOT need to be replaced. Re-install the button shaft and grommet and verify that the switch is operating normally.

The easiest way to re-install the button shaft is with a standard soda straw that will fit through the opening in the housing. Insert the button shaft into the end of the straw with the cupped end facing the end of the straw. Hold the straw horizontally and insert the straw into the opening in the housing so it engages with the switch handle on the circuit board.

CuppedEndOfShaft

Rotate the housing so the straw is angled upward to allow the button shaft to slide downward and engage the switch handle on the circuit board.

StrawTiltedUpward

Hold the housing with the hole on top to keep the button shaft in place. Use the orange stick or other non-marring wooden or plastic tool to re-install the grommet. Press the lower flange on the grommet through the hole all the way around the grommet.

ButtonShaft-grommet

Replacing the Button Shaft

The tools you will need include an “orange stick,” the replacement button shaft, a 4-40 screw or threaded stand off like the one shown, and a small pair of needle nose pliers. (the pliers don’t have to be as nasty looking as the ones shown here - ha!)

ToolsNeeded

Step 1

Thread a #4-40 male screw or spacer into the access hole in the plastic pin retainer in the upper mic interface circuit board.
Pull straight outward to remove the circuit board and reveal the mute switch assembly.

Step1

Step 2

If present, remove the protective film that covers the LCD and switch.

Step2

Step 3

Remove the mute switch diaphragm grommet with the orange stick or other non-marring wooden or plastic tool. Pry the outer edge of the grommet around its perimeter to separate it from the housing. The grommet will be re-installed in the final step.

Step3

Step 4

You may need to scrape away some of the adhesive to release the shaft from the switch actuator with the orange stick or X-acto knife.
BE CAREFUL NOT TO DAMAGE THE WHITE SWITCH ACTUATOR SHAFT OR CIRCUIT BOARD COMPONENTS.
Grasp the metal extension shaft and gently pull it outward through the grommet hole. Discard this shaft, as it will be replaced with a new part.

Step4

Step 5

Clean any residue of the adhesive from the white switch actuator. BE CAREFUL NOT TO DAMAGE THE SWITCH ACTUATOR.

Step 6

Install the replacement button shaft through the opening in the housing and engage the white switch actuator shaft.

Step6

Step 7

Hold the housing with the hole on top to keep the button shaft in place. Use the orange stick or other non-marring wooden or plastic tool to re-install the grommet. Press the lower flange on the grommet through the hole all the way around the grommet. A simple check for proper installation can be done with your thumb and finger to verify that the grommet will rotate freely within its constraints.

Step7

Step 8

Depress the grommet a few times to make sure that you can feel a tactile “snap” as the switch is activated.

Step 9

Align the indexing notch on the circuit board with the mating tab in the housing and gently seat the circuit board assembly. Make sure the connector pins are aligned before applying any pressure to avoid damage to the connector.

Step9

Step 10

Attach a mic capsule and test the operation of the transmitter.

NOTE:  If there is no audio, the 6-pin connector is not lined up and making contact.