ONKYO TX-SR805
Instrukcja Serwisowa

TX-SR805/SA805 OPERATION CHECK-4
Condition of Protect Mode
The unit will go into Protect mode under the following conditions. (T: Thermal sensor temperature)

1. Thermal condition
Immediately T <= -30 C or Immediately T > 110 C VOLH

2. DC voltage condition
The sum of dc voltage of 7 channel speaker outputs is more than 7 V.

3. Current condition
Protect will be On if speaker output ac current >= 35 A Protect will not be On if speaker output ac current >= 11.7 A This condition is equivalent to OPERATION CHECK-2. Refer to the page 2. Test wave form:

2 msec 2 msec

20 msec

Condition of Power Supply Voltage Control
The power supply voltage(VH, VM or VL) for power amplifiers is changed by the relays: RL6601, 6602, 6611, 6612 on NAPS-9040. VH > VM > VL T: Thermal sensor temperature VOLH: Pin #99 input voltage of Main microprocessor: Q7001 (Refer to SD-4:D5 and SD-8:D2 of Schematic Diagram) This is created by the largest ac voltage in 7 speaker outputs. Conditions: Speaker imp. = 6 or 8 ohm VH: 0V < VOLH < 0.4V and T < 85 C VM: 0.4V < VOLH < 2.0V and T < 85 C VL: 2.0V < VOLH < 3.3V(Vcc) and T < 85 C VL: T > 85 C Speaker imp. = 4 ohm or BTL VM: 0V < VOLH < 0.4V and T < 85 C VL: 0.4V < VOLH < 2.0V and T < 85 C VL: 2.0V < VOLH < 3.3V(Vcc) and T < 85 C VL: T > 85 C

Condition of Cooling Fan Operation
The cooling fan will stop or rotate under the following conditions. Thermal Sensor Temperature(T) 0V 60 C STOP 0.4V STOP 2.0V MID HIGH HIGH HIGH SPEED SPEED SPEED SPEED MID HIGH HIGH SPEED SPEED SPEED 70 C 80 C Note: �VOLH=0.4V� is equivalent to 0.8W(8 ohm, 7 ch) �VOLH=2.0V� is equivalent to Max power(8 ohm, 3 ch)

STOP

LOW MID SPEED SPEED