HT-CT780
27
SECTION 4
TROUBLESHOOTING
1. “PRTECT” is displayed on the
fl
uorescent indicator tube after turning the power on
“PRTECT” is displayed on the
fluorescent indicator tube after
turning the power on.
Yes
“PRTECT” is not displayed on the
fluorescent indicator tube, when
removing the speaker (SP1, SP2,
SP3, SP4) and turning the power
on.
No
Replace the IC503 on the MAIN board.
IC503 on the MAIN board is burned
out.
Yes
Yes
Check and replace the speaker (SP1,
SP2, SP3, SP4) and connection cable
(SPC1, SPC2).
The voltage of the following is 3.3 V.
MAIN board: IC102 pin 56
The voltage of the following is 3.3 V.
MAIN board: IC102 pin 50
No
The voltage of the following is 12 V.
MAIN board: IC502 pin 4
No
Yes
Yes
No
No
No
No
OUT_D line (pin 27, 28), OUT_C line
(pin 32), OUT_B line (pin 35) and OUT_A
line (pin 39, 40) of IC503 on the MAIN
board do not short-circuits or opens.
Replace the IC503 on the MAIN board.
Yes
Replace the IC503 on the MAIN board.
Yes
Yes
Mounted parts on the OUT_D line (pin 27,
28), OUT_C line (pin 32), OUT_B line (pin
35) and OUT_A line (pin 39, 40) of IC503
on the MAIN board short-circuits or opens.
The PWM signal is inputted INPUT_D
line (pin 15), INPUT_C line (pin 14),
INPUT_B line (pin 6) and INPUT_A line
(pin 5) of IC503 on the MAIN board.
Repair the short-circuit and opening of
mounted parts.
Yes
Check and repair the area
surrounding IC502 on the MAIN
board.
Check and repair the area surrounding
IC501 on the MAIN board.
The voltage of the following is 3.3 V.
MAIN board: IC102 pin 121
Replace the complete MAIN board.
No
Yes
Check and repair the area
surrounding Q950, Q952 on the
POWER board.
(Except US, Canadian and Taiwan models
only)
Ver. 1.1
