Specifications

54
START
VERY LOW
OR
NO 12DB SINAD
NOISE AT
PIN 9 OF
IFIC IC6?
CHECK AFIC
IC412
IS 12DB
SINAD NEAR
-103DBM?
INJECT A
45.1MHz
SIGNAL AT C71
IS 2ND LO
ON FREQ?
IS PIN 1
OF IFIC AT
4.4V DC?
NOISE AT
SPKR WHEN RADIO
IS UNSQ'D?
CHECK 2ND LO
XTAL AND
COMPONENTS
CHECK VDC
OF ALL PINS OF
IFIC IC6
ARE
VOLTAGES
ON PINS OK?
CHECK EXTERNAL
COMPONENTS
CONNECTED TO IFIC.
IF OK REPLACE IC6
CHECK EXTERNAL
COMPONENTS
CONNECTED TO IFIC
INJECT A
45.1MHz
SIGNAL AT C70
IS 12DB
SINAD NEAR
-115DBM?
CHECK XTAL
FILTERS
XF1 & XF2
INJECT
ON CH SIGNAL
AT C62
YES
YES
YES
IS 12DB
SINAD NEAR
-113DBM?
IS 1ST LO AT
PIN 4 OF T2
NEAR 3DBM?
IS Q16
BIASED
COREECTLY?
CHECK IF AMP AND
PERIPHERAL
COMPONENTS
YES
NO
BAD MIXER
CIRCUITRY
(D6, T1, T2)
CHECK VCO
SYNTH
INJECT
ON CH SIGNAL
AT C601
CHECK IFIC
IC6
IS 12DB
SINAD NEAR
-119DBM?
IS Q601
BIASED
CORRECTLY?
CHECK FRONT END
FILTERS FOR OPENS
OR SHORTS
CHECK RX5V (Q2) AND
BIAS COMPONENTS
(R64, R601, R602, L605)
CHECK HARMONIC
FILTER AND
ANTENNA PATH
CHECK IFIC
YES
NO NO
NO
YES
NO NO
YES
YES
YES
YES
NO NO
NO
YES
YES
NO NO
Figure 9.1. Troubleshooting Flow Chart for Receiver