Visual Inspection - Tait TB8100 Service Manual

8.7

Visual Inspection

Task 1 —
Check for Physical
Damage, Missing or
Misplaced
Components
Task 2 —
Check Quality of
Solder Joints
Task 3 —
Check DC Supply
Task 4 —
Check RF
Connectors
144 Power Amplifier Fault Finding
The following procedures are intended as a guide for quickly finding basic
faults in the PA before proceeding to the more detailed checks. As some of
these checks apply only to particular models of PA, you only need to carry
out the checks which are appropriate for the model of PA under test. Unless
otherwise indicated, the circled numbers in the following instructions refer
to Figure 8.6 on page
1. Remove the cover, as described in
and Reassembly" on page
2. Has the PA been dropped? Inspect the cover and heatsink for damage.
Check each board for loose or missing components. Replace any
defective board.
3. Has the PA been too hot? Check the boards and heatsink for
discoloration. Replace any defective board.
4. Check for loose bridging links
The quantity and location of these links will depend on the model of
PA.
5. Check that all screws are in place and secured correctly. Refer to
"Screw Torque Settings" on page
6. Check that the ambient air temperature sensor board
properly and in the correct place. Replace the board if it is damaged.
1. Check that the RF power transistor (MRF9060)
board(s) is soldered correctly. Refer to
Power Transistor" on page
2. Check the overall quality of the solder joints. Repair cracked or dry
joints as necessary.
1. Check whether the reverse polarity protection diode
(short circuit). If it has, replace the 6W board.
2. Check the DC supply
3. Check the DC supply
1. Check the SMA connector
nents near this joint (e.g. C100 and L100).
2. Check the N-type connector solder joint
removal of the shield lid. Refer to
Directional Coupler Board" on page 188
mounting and soldering the N-type connector.
146.
"Power Amplifier Disassembly
173.
b
, and missing or loose RF links
174.
184.
g
to the 6W board.
h
to the 60W board(s).
i
solder joint. Also check the compo-
"Replacing the Low Pass Filter/
© Tait Electronics Limited September 2006
d
is fitted
e
on the 60W
"Replacing the 60W RF
f
has failed
j
. This requires the
for a description of
TB8100 Service Manual
c
.