Rohde & Schwarz 1164.4391.03, Service Manual

Page: 168 / 254

Module Replacement R&S FSP
1164.4556.82 3.64 E-1
Replacing External Mixer Board A180 (Option B21)
(see chapter 5, spare parts list, item 2900, and illustrations 1164.4391 and 1157.1764.)
The board is installed in rear part of the instrument.
Opening Instrument and Removing Board
Switch off instrument, disconnect from mains, unscrew 4 rear panel feet (450) and pull off enclosure
(410) toward rear.
Unscrew the two countersunk screws (260) at the top of the instrument and the three countersunk
screws (250) at the fan side, lift the cover at the top (240) of the instrument to the left side and take
off.
Undo RF cable W39 at the top of the external mixer board.
Place the instrument on its side and remove all RF cables to the board at the bottom of the
instrument.
Pull the board out toward the bottom of the instrument.
Do not damage RF cable W39 on the top!
Note : The board can be loosened from the motherboard connector by carefully applying
pressure from the bottom through the motherboard slots.
Installing Board and Completing Instrument
Insert the new board into the instrument and reconnect all RF cables.
Note: Do not forget RF cable W39 at the top of the board.
Note the labeling on the motherboard.
Put the top cover (240) on the instrument and fasten it in place with 2 countersunk screws (260) and
3 countersunk screws (250).
Slide on the enclosure (410) and screw on the 4 rear panel feet (450).
After the external mixer board is replaced, a cold start must be performed.
Plug in the power cable, switch on the power switch and press the ON key.
After starting the instrument, check the log file for any errors:
- [
SETUP : SYSTEM INFO : SYSTEM MESSAGES ]
Start the selftest and check results:
- [
SETUP : SERVICE : SELFTEST ], then [SELFTEST RESULT]
Start the system error correction and check results:
- [ CAL : CAL TOTAL ], then [ CAL RESULTS ]
Check characteristics as defined in chapter 1,Test Sequence for Option External Mixer B21.
Create backup of the EEPROM data (see chapter 2, section "Adjustment of Module Data").