Pioneer HTP-072 Service Manual page 30

1
A
3.3 TEMP (AMP overheat) error detection
For detection of a TEMP error, the unit monitors both the THER_DET and OVERLOAD & DC_DET signals.
If a TEMP error is detected, the processes shown below will be performed. The processes shown below are rough
operational specifications and are not the actual commands from the mounted components.
After a TEMP error is detected, the count of protection activation detections will be updated.
PROTECT2
Counter: Temp2
P2_2 (pin 70)
(THER_DET from MAIN Assy)
Normal Operations
B
*1
Is THER_DET detected?
Yes
Is the VOL value 5
or less?
No
C
Deduct 3 from the current VOL
value. Have "TEMP" flashing
on the FL display for 3 sec.
Prohibit detection of
THER_DET for 2 min.
*2
Detection of THER_DET
No
is resumed after 2 min.
Is THER_DET detected?
D
*1: The detection interval must be 1 sec or less.
*2: If PROTECT 2 is detected while THER_DET detection
is prohibited for 2 min, the PROTECT 2 function will
be activated.
3.4 How to cancel the status after detection of the DC error
Key Operation
E
(STANDBY state)
[ADVANCED SURROUND]
+ [STANDBY/ON] keys
(press and hold the keys
for 2 seconds.)
(Normal display)
[Detailed explanations]
F
If the AC power cord is plugged in while the AVR is prohibited from being ON because of DC detection, the HDMI LED will
flash at intervals of 500 msec.
30
1
2
No
Yes
POWER OFF (STBY)
Yes
FL Display
Simultaneously holding the [ADVANCD SURROUND] and [STANDBY/ON] keys on the
front panel pressed for 2 seconds will cancel Key Input Inhibition mode after a DC error
detection and turn the unit ON.
HTP-072
2
3
PROTECT1
Counter: OVER / DC
P0_3 (pin 85)
(OVERLOAD & DC_DET from AMP6 Assy)
PROTECT1 Function
<PROTECT1: Voltage at Pin 85>
NORMAL: 3.3 V
When ASO destruction (excess current) is detected: 0.83 V
When DC is detected: 1.45 V
<Operation upon detection>
When ASO destruction is detected: POWER OFF (STBY)
When DC is detected:
CASE 1 (Instantaneous detection [for less than 3 sec]): Speaker RELAY OFF
CASE 2 (Continuous detection [for 3 sec or longer]): Shutdown and flashing of the HDMI LED
(To turn the unit back ON again, simultaneous pressing of the two keys is necessary.
-> See "3.4 How to cancel the status after detection of the DC error".)
Normal Operations
*3
DC detected?
Yes
MUTE ON and ALL Speakers/
Phones Relay are set to OFF.
Timer START is performed
for 3 sec.
After 3 sec,
No
DC is rechecked.
Is DC detected?
Yes
POWER OFF (STBY) and
HDMI LED flashing.
*3: The detection interval must be 1 sec or less.
Time (sec.) Description of Indications
usually
Normal display
3
4
No No
Is ASO detected?
Yes
POWER OFF (STBY)
4