Pioneer 1014TX-K Service Manual - Page 114

1 2 3 4 7. GENERAL INFORMATION 7.1 DIAGNOSIS 7.1.1 PROTECTION CIRCUIT CONTROL SPECIFICATION A Microcomputer-related ports DC_PROT (pin 74 of IC501: MAIN CONTROL Assy) Input port : For DC detection OL_DET (pin 73 of IC501: MAIN CONTROL Assy) Input port : To detect overloading at the amplifier (Interrupt port) If this status continues for more than 3 seconds, the power is turned off (for Standby mode). Do not accept the key input afterward. (Flash it always till turns the primary side off.) If the port becomes "H" within 3 seconds, the unit resets automatically. FAN_STOP (pin 92 of IC501: MAIN CONTROL Assy) Input port : To detect Fan forced stop FAN_DRIVE (pin 91 of IC501: MAIN CONTROL Assy) : For Fan on/off B TEMP2 (pin 44 of IC3001: DISPLAY Assy) Input port : To detect temperature 12V_DET (pin 41 of IC3001: DISPLAY Assy) Input port : To detect 12V trigger The following control processes are activated immediately before the relay system is turned on upon power-on. The time is 4.8 seconds after power-on. (Control of the relay system is enabled 5.2 seconds after power-on.) Only DC detection is enabled 2 seconds after power-on to activate it before other protection functions. DC_PROT port performs the chattering check for 1 msec. In addition, there is the case that detection delays for maximum 20 msec because performs monitor of DC_PROT port with a main loop. Even if turns the primary side off and turns on once again. If detects DC once and turned the power off, do not accept the key input afterward. However, power on is possible when the following key was pressed to be able to key input in the protection line and service. 1. Test mode (remote control code : A55F) 2. When the STEREO/DIRECT key and SIGNAL SELECT key are both held pressed for 2 seconds. (Be effective when turned the power off by DC detection regarding 2.) C 1 DC detection (defect detection) Only DC detection is enabled 2 seconds after power-on. If there is a fault in the power amplifier or a high-level signal lower than5 Hz is input, the DC_PROT port becomes "L" Detecting "L" the microcomputer performs the following operations: 1. System muting on 2. Speaker relay off (Control with the display microcomputer) The warning indication "AMP ERR" appears on the FL display. 2 Overload detection (abnormality detection) If the speaker terminals are short-circuited or low-load driving is detected, the OL_DET port becomes "L" Detecting "L" edge interrupt in an interrupt process, the microcomputer performs the following operations: 1. System muting on 2. Speaker relay off (Control with the display microcomputer) 3. Power off (Standby mode) D Protection Process List Item Detection Method Process Warning Indication Remarks DC detection Detects when the DC_PROT port becomes "L". Turns muting on and speaker relay off, then turns off the power after 3 seconds. If the power is turned off, flashes the MCACC Flashing "AMP ERR" for 3 LED. seconds. Do not accept the POWER key. If the DC_DET port becomes "H" within 3 seconds, the unit resets automatically. E Overload detection Detects when the OL_DET port becomes "L" (checks by interrupt). Turns muting on and speaker relay off, and immediately turns off the power. None Thermal shut down Detects when the TEMP2 port becomes "H". Turns muting on and speaker relay off, then turns off the Flashing "OVERHEST" power after 3 seconds. for 3 seconds If the TEMP2 port becomes "L" within 3 seconds, the unit resets automatically. After the power off, the key input is possible once again. 12V trigger Detects when the 12V_DET port short detection becomes "H". Turns 12V_TRG port to "L", then turns off the the 12V output. Flashing "12V TRI ERR" Only a fan that is assigned 12V TRIG is valid. Release the FL indication with the power on/off. F 114 VSX-52TX 1 2 3 4