General Information; Diagnosis; Protection Circuit Control Specification - Pioneer VSX-45TX Service Manual

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7. GENERAL INFORMATION

7.1 DIAGNOSIS

7.1.1 PROTECTION CIRCUIT CONTROL SPECIFICATION

A
Microcomputer-related ports
FAN_DRIVE (Expansion IC) : For Fan on/off
TEMP_IN (pin 94)
Input port (A/D) : To detect temperature
FAN_STOP (pin 95)
Input port : To detect Fan forced stop
OL_DET (pin 73)
Input port : To detect overloading at the amplifier
(Interrupt port)
DC_DET (pin 63)
Input port : For DC detection
B
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.
1 Thermal and Fan detection, and Fan
control
1) Thermal detection and Fan control
Valid with American and Japanese models only.
C
TEMPIN Temperature
(V) (°C)
More than 4.10 More than 125
3.83 to 4.09 110 to 125
2.91 to 3.82 80 to 110
2.58 to 2.90 70 to 80 Leading hold
Less than 2.52 Less than 70
Valid with European and other general-area models only.
TEMPIN
Temperature
(V) (°C)
More than 3.58 More than 100
D
3.30 to 3.57 90 to 100
2.91 to 3.29 80 to 90
2.53 to 2.90 70 to 80 Leading hold
Less than 2.52 Less than 70
* By poor contact of Thermistor and alien substance mixture, there are the following
cases displayed FL.
Become STBY after having done flushing with "THDCT NG" for three seconds.
By opening of thermistor junction or energization in very cold place (less than
-15°C),TEMP line becomes high impedance. And when TEMP port became equal
to or less than 0.1V.
2) Fan detection
If the fan is forcibly stopped, the FAN_DET port becomes "L"
Detecting "L" the microcomputer performs the following
E
operations:
1. System muting on
2. Protection relays off
The warning indication "FAN STOP" appears (flashing) on the
FL display.
If this status continues for more than 3 seconds, the power is
turned off (for Standby mode).
If the port becomes "H" within 3 seconds, the unit resets
automatically.
FAN_DET port performs the chattering check for 7 msec.
In addition, there is the case that detection delays for maximum
F
20 msec because performs monitor of FAN_DET port with a main
loop.
116
1
2
Fan Remarks
ON Mute ON & speaker relay OFF :
The warning indication "OVERHEAT"
ON Leading hold
ON
Mute OFF & speaker relay ON :
Normal mode
OFF
Fan Remarks
ON Mute ON & speaker relay OFF :
The warning indication "OVERHEAT"
ON Leading hold
ON
Mute OFF & speaker relay ON :
Normal mode
OFF
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3
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)
3 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_DET 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.
If this status continues for more than 3 seconds, the power is
turned off (for Standby mode) and flashes the standby LED.
Do not accept the key input afterward.
(Flash it always till turns the primary side off.)
If the port becomes "L" within 3 seconds, the unit resets
automatically.
DC_DET 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_DET port with a main
loop.
Even if turns the primary side off and turns on once again,
standby LED flashes as it is.
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.)
VSX-45TX
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