When the bottom case is closing. If the fan revolving starts
within 10 minutes, the function is correct working.
Otherwise keep outputting 1W from both channels of the
product when the bottom case is opening. If the fan revolving
starts within 5 minutes, the function is correct working.
REMARK
Do not output over 1W when the bottom case is open.
VCC CONTROL
The regulation of primary voltage is not so higher
intentionally for decreasing the no-load loss. Therefore, this
circuit is used for the product to keep the voltage tolerance
of the power IC. This circuit do not work when the output is
from 0 to approx. 1Vrms. Then VCC is supplied from D709
only. When the output is more than 1Vrms, through D701-
D704, R722, D706, and Q703 is on, current is supplied
from Q702. When the output is over approx. 3Vrms, D709
is off, and VCC is supplied from Q702 only.
SPEAKER PROTECTION
1. When either terminal of BTL outputs connect with GND
(chassis) by mistake, the speaker protection circuit will
work as follows. through R707-R710, Q704 or Q705 is
on, and Q706 is on. Then #5Pin for Q701 is 0V, power IC
(Q701) will be in power off. Therefore, the product will be
STAND-BY status.
2. When the VCC CONTROL circuit is working correctly,
maximum current of R825 is 1A, and voltage between
R825 load is maximum 0.33V. When both terminals of BTL
outputs are shorted on outputting over 0.25W, R825 is
supplied over 2A, Q807 and Q803 is on, and the product
will be STAND-BY status.
CD 5V ON/OFF CONTROL
The voltage for CD (CD 5V) is supplied from QX04 when
the following conditions are satisfied fully. (for noise and
laser protection)
1. Setting a disc on the product, and QU08 is on.
2. Closing top panel, and #78Pin for QU10 is 0V.
3. The product is in CD mode.
MUTE CONTROL
Mute signals output from microprocessor (QU10) are
"MUTE (Pin No.37)", "MUTE2 (Pin No.7)", and "DSC MUTE
(Pin No.5)".
Fig.1 is workable output terminals by each mute signals,
Fig.2 is the status of each mute.
2-7
Fig.1
Q701(SPK)
QN01-QN04
(PHONE)
QX05,QX06
(SUB WOOFER)
QX07,QX08
(LINE OUT)
QE01
MUTE YES YES YES NO NO
MUTE2 NO NO
DSC MUTE NO NO NO NO YES
NO
YESNO
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