Panasonic SA-PT170PH Service Manual page 37

7.1.2. Troubleshooting Guide
Symptom
FL display blinking with
abnormal segment when
power ON the set or "F61"
First Power ON Display
immediate show " F61".
Check VCC to Power
Amplifier IC (Pin 1)
Check Q5749, Q5750,
Q5753, Q5754, Q5747,
Q5748
Power ON for a while then
only trigger "F61".
(Symptom always happen)
Power ON for a while and
then trigger "F76"
Checking Items
Check the soldering of the SMPS
P. C.B.
Is there any solder crack at area
(D5802, Q5841, R5842)
Check all the VDD supply line
30V & +18V
Is there any solderability at area
of feedback circuit
Check feedback circuit.
Check speaker output by
using multi-meter
Check Power Amplifier
IC (Pin 1)
Check the fan connection &
feedback loop:
If the fan not proper connected,
"F61" will trigger when the
volume increase.
If the fan is not working, check
for fan circuit.
Check the soldering of the SMPS
P. C.B.:
Is there any solder crack at area
(D5802, Q5841, Q5842)
Check all the supply line VDD
Check if there are supply
voltages from SMPS P.C.B
to Main P.C.B. at CN2016
& CN2017:
CN2016 F (Pin 1), VP (Pin 3),
F (Pin 2)
CN2016 5V (Pin 7), av (Pin 8),
18V (Pin 11)
CN2017 7V (Pin 1)
Repair Items
Tou ch-up the solder crack area/
Change the defective parts.
(D5802, Q5841, R5842)
(DCDET)
(D5807)
Touch-up the necessary areas
IC5801, PC5720, D5725
Change the defective parts.
Power Amplifier IC
IC5100/IC5200/IC5300
P/N = AN17831A
Replace necessary parts.
Re-connect the Fan to CN5704
Fan circuit: Q5740, Q5742,
Q5741, Q5744, D5755, D5745
Touch-up the solder crack area/
Change the defective parts.
D5802, Q5841, R5842
(DCDET)
D5840, D5841, D5842, D5843
( 30V Detect)
Feedback Circuit: IC5801,
PC5720, D5725
Check and change the possible
defective parts.
FP2901(Fuse Protector),
T2900, D2901, D2906,
D2908, D2909
IC2903 (DC-DC Converter IC)
& related regulator circuit
components
IC2900 (DC-DC Converter IC)
& related regulator circuit
components
37
Remarks
SMPS
P. C.B.
Refer to
Fig. 1
Analog
AMP
P.C.B
Refer to
Fig. 3
Analog
AMP
P.C.B
Refer to
Fig. 4
SMPS
P.C.B.
Refer to
Fig. 2