Nokia 6560 Service Manual 8rh25rf
CCS Technical Documentation
RH-25 Series Transceivers
Troubleshooting - RF
Issue 1 10/2003 Confidential ©Nokia Corporation
RH-25
Troubleshooting - RF CCS Technical Documentation
Contents
Page No
Transceiver Troubleshooting ......................................................................................... 3
Receiver Troubleshooting ............................................................................................3
General instructions for RX troubleshooting............................................................ 3
Path of the received signal ........................................................................................ 3
Fault finding charts for receiver chain ...................................................................... 4
Transmitter Troubleshooting .......................................................................................9
General instructions for TX troubleshooting ............................................................ 9
Path of the transmitted signall................................................................................... 9
Fault finding charts for the transmitter.................................................................... 10
Synthesizer Troubleshooting .....................................................................................16
19.44 MHz reference oscillator............................................................................... 16
RX VHF .................................................................................................................. 17
TX VHF................................................................................................................... 17
UHF Synthesizer..................................................................................................... 18
Page 2 ©Nokia Corporation Confidential Issue 1 10/2003
RH-25
CCS Technical Documentation Troubleshooting - RF
Transceiver Troubleshooting
The first thing to do when you are encountered with a problem is to carry out a thorough
visual check of the module. Make sure that:
• there are no mechanical damages
• the solder joints are OK
Note: Before changing anything, ALL SUPPLY VOLTAGES AND THE SYSTEM
CLOCK / SLEEP CLOCK should be checked.
Receiver Troubleshooting
General instructions for RX troubleshooting
Start the Phoenix software and use it to start the required RX-mode of the mobile phone.
The troubleshooting flowchart is divided into three steps: (1) general checking, (2) local
checking and (3) RX-chain checking.
Note: Before changing ASICs or Filters, all solderings and missing components must
be checked visually. After any possible component changes, the phone must be
tuned with the Phoenix autotune SW.
Path of the received signal
Block level description of the receiver:
(Antenna/ext RF) – Diplexer – Duplexer – Low Noise Amplifier (LNA) – RX band filter –
First mixer – 135.54 MHz RX IF filter – IF-amplifier – second mixer – 14 kHz low-pass filter – adjustable IQ amplifier – Baseband.
Issue 1 10/2003 ©Nokia Corporation Confidential Page 3
RH-25
Troubleshooting - RF CCS Technical Documentation
Fault finding charts for receiver chain
AMPS
Apply 881.49MHz = ch
383 -116dBm, 8kHz
dev, 1kHz sine to
external RF connector
(X900)
Y
Connect HS to cellular
tester, open AF: 1kHz
sine meas SINAD
AF:>12dB
N
Y
AMPS RX chain OK
Check UHF Vc (from
C773) V: 1.8 ... 2.1V
Y
Check RXVHF Vc
(from C720)
V: 0.7 ... 1.3
Y
Apply 881.49MHz
-30dBm, sine signal
external RF connector
(X900)
N
N
Start troubleshooting
Start troubleshooting
Page 4 ©Nokia Corporation Confidential Issue 1 10/2003
RH-25
CCS Technical Documentation Troubleshooting - RF
Check input level at
diplexer (Z907)
Y
Check input level at
duplex filter
Y
Check input level at
LNA input
Y
Check RF level at
RX800 band filter
input
N
Change EXT RF
connector
soldering and
components in
antenna circuit
before changing.
NOTE: Check all
NOTE: Check all
N
Change diplexer
(Z907)
soldering and
discrete
components of
front end.
N
Change duplex filter
(Z906)
NOTE: Check all
solderings and
N
Change TACO (N801)
discrete components
around TACO before
changing.
Y
Check RF level at
MIX1Ain P/N
Y
N
Change TACO (N801)
Issue 1 10/2003 ©Nokia Corporation Confidential Page 5
RH-25
Troubleshooting - RF CCS Technical Documentation
Check RF level at RX
IF filter input at
135.54MHz
Check RF level at RX
IF filter output at
135.54MHz
Y
Check RX I and Q
signals at I: J801(+),
J803(-) and Q:
J804(+), J802(-)
Check RF level at
N N
J751 and J752 at
2034.06MHz
Y
Change TACO (N801)
N
Change RX IF filter
(Z830)
Check RF level by
N
L730 without having
electrical contact at
271.08MHz
Start synthesizer
troubleshooting
NOTE: Check all
discrete
components and
voltages around
TACO.
N
Start synthesizer
troubleshooting
Y
Check UEM and start
baseband
troubleshooting
Y
Change TACO (N801)
Page 6 ©Nokia Corporation Confidential Issue 1 10/2003
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