Tektronix RFM150, Instruction Manual

Page: 158 / 278

Replacement Procedures
6–6 RFM 150 Instruction Manual
Replacing the Front Panel Circuit Board Assembly, Speaker,
Encoder, or Keypads
Use this procedure to replace the Front Panel circuit board assembly,
the speaker and speaker gasket, the encoder and encoder gasket, and
the keypads.
1. Perform Instrument Disassembly on page 6–1. This includes
turning off the instrument and making sure there is no connection
to AC power, RF input, or Interface Port.
2. Without removing any screws, lift the board set (consisting of the
Processor/Power Supply circuit board assembly and the Analog
Converter circuit board assembly) from the instrument housing
just enough to reach the cable that connects the board set to the
Front Panel circuit board assembly. Disconnect the cable.
3. Remove the board set from the instrument.
4. Desolder the speaker and encoder switch leads from the Front
Panel circuit board assembly at J2, J3, and J4, as shown in
Figure 6–3. (They will later be soldered to the replacement Front
Panel circuit board assembly.)
5. Remove the 15 screws that hold the Front Panel circuit board
assembly to the instrument. See Figure 6–3. Remove the stiffener,
then lift the Front Panel circuit board assembly out of the
instrument housing.
6. Replace the encoder (optional):
a. Using a 5/64 in hex wrench, remove the large knob from the
front panel. Remove the spacer, if installed.
b. Using a 9/16 in wrench, remove the nut and two washers from
the encoder.
c. Working from the inside of the front panel, lift out the
encoder. Inspect the gasket and replace if necessary.
Replacement Procedures
6–6 RFM 150 Instruction Manual
Replacing the Front Panel Circuit Board Assembly, Speaker,
Encoder, or Keypads
Use this procedure to replace the Front Panel circuit board assembly,
the speaker and speaker gasket, the encoder and encoder gasket, and
the keypads.
1. Perform Instrument Disassembly on page 6–1. This includes
turning off the instrument and making sure there is no connection
to AC power, RF input, or Interface Port.
2. Without removing any screws, lift the board set (consisting of the
Processor/Power Supply circuit board assembly and the Analog
Converter circuit board assembly) from the instrument housing
just enough to reach the cable that connects the board set to the
Front Panel circuit board assembly. Disconnect the cable.
3. Remove the board set from the instrument.
4. Desolder the speaker and encoder switch leads from the Front
Panel circuit board assembly at J2, J3, and J4, as shown in
Figure 6–3. (They will later be soldered to the replacement Front
Panel circuit board assembly.)
5. Remove the 15 screws that hold the Front Panel circuit board
assembly to the instrument. See Figure 6–3. Remove the stiffener,
then lift the Front Panel circuit board assembly out of the
instrument housing.
6. Replace the encoder (optional):
a. Using a 5/64 in hex wrench, remove the large knob from the
front panel. Remove the spacer, if installed.
b. Using a 9/16 in wrench, remove the nut and two washers from
the encoder.
c. Working from the inside of the front panel, lift out the
encoder. Inspect the gasket and replace if necessary.