Panasonic SA-HT17PP, Руководство по обслуживанию

Страница: 19 / 66

3. When [TUNE UP] is pressed, display “SUM ****”, “****” is the check sum of ROM for ROM correction.
If there is no EEPROM IC, “NO EPROM” is displayed.
4. Press “POWER” button on main unit or remote control to exit this mode.
11.5. The Shutdown And Short Circuit Protection Detection
It detects S_DET and DC_DET input port for malfunction.
1. S_DET Function (SHORT DETECTION)
It is to detect a short in the Power Supply. The detection of S_DET starts after 700ms after POWER ON.
After that, it is always detected for any malfunction.
Upon detection, the FLD display “F76” and the system is POWER OFF by setting POWER_RELAY port to OFF.
2. DC_DET Function
DC_DET (pin 94) on micon is used to detect FAN LOCK. During POWER ON, it will be ignored until ALL_MUTE is released.
Upon detection, FLD display “FAN LOCK” and MUTE_ALL will be set to ON. If any button is pressed, it is made to scroll error
message “SWITCH OFF POWER”. After Power Off and On,this condition is reset, and DC_DET will resume detection of error.
It also sets MUTE_SW to ON, to switch OFF the power amplifier.
3. FREQUENCY LIMITER
Due to surround speaker change from 6.5 cm to 8 cm. We have to limited certain output level to certain FOR FRONT L/R
channel and SURROUND L/R cut off frequency in order to avoid speaker noise.
4 ports are used for this purpose. 2 ports are used for front L/R channel, 2 ports for surround L/R channel.
Front Left/ Right Freq limiter (Port Name: FRONT_fc1[pin49], FRONT_fc2[pin50])
Surround Left/ Right Freq limiter (Port Name: SURR_fc1[pin47], SURR_fc2[pin48])
For FRONT L/R
For SURROUND L/R
19
SA-HT17PP