Troubleshooting - Sony HT-MT300 Service Manual

HT-MT300/MT301
1. Protection mode is occurs after turning the power on.
When protection mode is occurs, all LEDs are fl ash for 10 seconds and turn the power off.
Note: Please remove the USB device before troubleshooting.
Protection mode is occurs after
turning the power on.
Yes
Protection mode is not occurs,
when removing the speaker
connection connector (CN1001) on
the MAIN board and turning the
power on.
Yes
Check and replace the speaker
(SP1, SP2).
2. The sound is not outputted
Check that the signals are inputted
to the following pins.
MAIN board: IC1000
pin 11, 22, 23, 24
Yes
Check that the signals are outputted
from the following pins.
MAIN board: IC1000
pin 40, 41, 48, 49
Yes
Check that the signals are outputted
from the following pins.
MAIN board: IC1001
pin 27, 28, 32
(front R-ch speaker)
pin 35, 39, 40
(front L-ch speaker)
Yes
Check the speakers' resistance are
not short-circuit (0 ) or open ( ).
24
SECTION 4

TROUBLESHOOTING

No
Protection mode is occurs even after
replacing IC1001 on the MAIN board.
Yes
Replace the MAIN board.
Reprogram the IC2000 (serial flash) on
No
the MAIN board and check the signal
again.
No
Replace the IC1000 on the MAIN board.
No
Replace the IC1001 on the MAIN board.
No
Replace the speakers (SP1, SP2)
Abnormality
Replace the IC2003 on the MAIN board
and check the signals again.
Abnormality
Replace the MAIN board.