Motorola HT 1000 service manual To Remove the RF PA, To Replace the RF PA

reflow, and may inadvertently move. Be careful when performing the following procedure.

Refer to Figure 17 for RF PA nomenclature.

PA Cover

Slab

	Solder
Leads	Pads

Figure 17 RF PA Nomenclature

To Remove the RF PA,	add flux to the leads of the device, and use a soldering iron and pair of
	tweezers to heat and lift each lead free and clear of its respective solder
	pad on the circuit board. Use the R-1319 Rework Station and the heat-
	focus head designed especially for removal of the RF PA. Attach the
	heat-focus head to the chimney heater. Adjust the temperature control
	to approximately 415 degrees F (215 degrees C) 445 degrees F (230
	degrees C) maximum. Apply solder paste to the exposed solder pads
	under the PA. Place the circuit board in the circuit board holder, and
	position the RF PA under the heat-focus head. Lower the heat-focus
	head until it is approximately 1/8”-1/4” (0.3cm-0.6cm) above the PA
	cover. Turn on the heater and begin the reflow cycle. Heating time
	should not be less than two minutes.
	Once the part has reflowed, before trying to remove the PA, carefully
	lower the circuit board holder as follows:
	• Loosen the thumbscrew on the shaft of the circuit board holder,
	• push the spring-loaded holder down and away from the heat-focus
	head, and
	• retighten the thumbscrew with the holder in the bottomed
	position.
	Grab the PA with a large pair of tweezers and remove it from the circuit
	board. Let the circuit board cool for approximately two minutes. Then
	remove the circuit board from the circuit board holder.
To Replace the RF PA;	if necessary, add solder to the PA ground plane on the printed circuit
	board. Then clean each PA lead solder pad on the circuit board to
	ensure alignment of the new RF PA. Prepare the sight by using solder
	wick and a soldering iron to remove all solder from the solder pads.
	Clean the solder pads with alcohol and a small brush. Dry and inspect.
	Ensure that all solder is removed.
	Once the preparation is complete, place the circuit board back in the
	circuit board holder. Add solder paste flux to the ground plane and to
	the leads’ solder pads. Once the flux is applied, place the new RF PA on
	the circuit board, making certain that the PA heatsink sits flush on the
	board. Position the heat-focus head over the RF PA and lower it to
	approximately 1/8”-1/4” (0.3cm-0.6cm)) above the PA cover. Turn on

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