Technical Manual

(IC401, PINS 1 AND 2)
>200mV?
REMOVE SHORT FROM
C407/R446 TO 0V.
CHECK XL401
CHECK IC401
IS TR403 (1st MIXER
O/P) >3mV?
CHECK TR410, L408
AND XL402.
CONNECT TR410 BASE
CHECK TR403
IS 455kHz PRESENT ON
TP405?
FL402 OR C444 FAULTY.
CHECK FL401, L410 AND
R444 (172MHz board).
TO 0V. IS RF LEVEL AT
NO
YES
YES
NO
YES
NO
YES
YES
YES
NO
‘C’
SHORT JUNCTION OF
C407/R446 TO 0V.
IS IC401, PIN 24 >3mV?
(TR410 COLLECTOR)
>25mV?
TR403 BASE >3mV?
AND L406.
IS RF AT TR402
NO
COLLECTOR >3mV?
CHECK TR401,
TR 402, L401, L416.
YESNO
YESNO
CHECK FL405
TAG11339-1
‘B’
IS 2nd LOCAL OSC. O/P
IS 1st LOCAL OSC. O/P
R479 (280MHz board).
TLA 852/FLA 872
TM1205 Issue 2 Page 5 - 13
Figure 5.7: Fault Finding Guide (Sheet 3 of 3)