Page 1
Approved by S.NAGAO Written by
WQ-19 2 817
/additional rule 3 (1st Issue 2003-03-19)
Date: 31-Oct.-2003 Model: SR4300/SR4400
Page: 1 / 3 REF.NBR: MZ03-047
Circulation: Application:
Subject:
Int.ref:
[PHENOMENON]
1) The protection circuit does not work when the power transistor was damaged.
2) When the power transistor was damaged, about 40 V outputs to speaker out.
3) The protection circuit function does not operate, then the unit will not be in POWER STANDBY mode
and the speaker output RELAY does not work.
[REASON]
1) When the transistor is damaged before turn on the unit, the micro processor can not detect protection
signal (Protect2).
2) Turn on the unit, the down edge of a protection signal (Protect2) is undetectable for about 2 seconds
after the micro processor reset
[SOLUTION]
The protection output signal of Protection IC is added to the "SPK MUTE" signal in hard, and
Speaker MUTE is always set to ON when abnormal occur protection
1.SR4300
DIGITAL/AUDIO PCB
1) Chip Resistor LS850
(100 ohm 1/16W part no. NN05101610 ) is changed to Silicon Diode
(Part no. *HD201810R--- 1SS400 POHM: EMD2, EIAJ: SC-79, JEDEC: SOD-523 ).
MAIN PCB
2) Chip Resistor DN601(Part no.HD20002000---Silicon Diode 1SS254 ROHM)
is added between
BASE of QN606 SEMICOM.COMP and No.5 pin of JFN101 Connector
2.SR4400
DIGITAL/AUDIO PCB
1) Chip Resistor RS928
(100 ohm 1/16W part no. NN05101610 ) is changed to Silicon Diode
(Part no. *HD201810R--- 1SS400 POHM: EMD2, EIAJ: SC-79, JEDEC: SOD-523 ).
MAIN PCB
2) Chip Resistor DN601(Part no.HD20002000---Silicon Diode 1SS254 ROHM)
is added between
BASE of QN606 SEMICOM.COMP and No.5 pin of JFN101 Connector
As for the details, Please see page2/3 and 3/3
[REMARKS]
The countermeasure apply to this claim only.
This problem apply to the Service code number XE00xxxxxxxxxx.
This improvement has been done in the production the Service code number XE01xxxxxxxxx and after.
SERVICE BULLETIN
The problem of the Speaker protection circuit.
x for information customer
complaint in case of service
mandatory
...................
Service code XE00
XE00xxxxxxxxxx
Page 2
Approved by S.NAGAO Written by
WQ-19 2 817
/additional rule 3 (1st Issue 2003-03-19)
SR4300/SR4400 SERVICE BULLETIN (REF.NBR:MZ03-047) page2/3
SR4300
LS850 is changed to
Part no.
*HD201810R
Caution
JFS08 (FPC CONNECTOR) side is
CATHODE
DIGITAL/AUDIO PCB
No.5 pin of JFN101
BASE of QN606
Adhesives :
SC608LVZ (Sony Chemical Corp. -“ Self-extinguishing adhesive) or the equivalent
Insulation tube is used
MAIN PCB
DN601
Part no. HD20002000
CATHODE MARK
