VSX-1015-K
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7. GENERAL INFORMATION
7.1 DIAGNOSIS
7.1.1 PROTECTION CIRCUIT CONTROL SPECIFICATION
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)
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
TEMP2 (pin 44 of IC3001: DISPLAY Assy)
Input port : To detect temperature
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.
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
Diagnostic mode
This mode is only for servicing and checking the circuit design,
and not open to users.
When the VIDEO 1 key and ENTER key are both held pressed
for 2 seconds in Standby mode, the power is turned on, and the
number of times of each defect or Speaker relay off by
abnormality detection is sequentially displayed on the FL display.
Displayed items:
• DC detection
• Overload detection
• Fan detection
• Temperature detection
Hold the VIDEO 1 key and ENTER key pressed for 2 seconds in
Standby mode.
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.
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 MCACC LED always till turns the primary side off.)
If the port becomes "H" within 3 seconds, the unit resets
automatically.
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 production line and service.
1. Test mode (remote control code : A55F)
2. When the ENTER key and VIDEO 2 key are both held
pressed for 2 seconds.
(Be effective when turned the power off by DC detection
regarding 2.)
DC : 003
OVER : 012
FAN : 000
TEMP : 000
Display changes
automatically
every 3 seconds.
