Onkyo TX-SR505 Service Manual page 60

OPERATION CHECK-2
SPEAKER PROTECT-2 (CURRENT DETECTION)
[When]
1. Exchange power transistors (Q6050 - Q6056, Q6060 - Q6066).
2. Exchange amplifier PC board ass'y (NAAF-8779).
<Note>
1. No input.
2. Do not check two or more channels at the same time.
3. Do not connect a dummy load to speaker terminal longer than 2 seconds.
[Procedure]
1. Press and hold down CD button, then press STANDBY/ON button while the unit is powered on.
" Test - _ " is displayed only for 5 seconds.
T e s t - _
2. Press AUX button, while " Test - _ " is displayed.
The unit will be in the state of " Test-4-00 ".
T e s t - 4 - 0 0
3. Repeatedly press + (TONE) button until " Test-4-35 " is displayed.
T e s t - 4 - 3 5
4. Connect the dummy load of 3 ohms to the Front L ch speaker terminals.
At this time, confirm that the speaker relay is not turned off.
T e s t - 4 - 3 5
5. Connect the dummy load of 1 ohm to the Front L ch speaker terminals.
At this time, confirm that the speaker relay is turned off and " Protect " is displayed.
P r o te c t
Disconnect the dummy load immediately after checking the display of " Protect ".
T e s t - 4 - 3 5
6. Check other channels according to the same procedure as 4 and 5.
7. Press the STANDBY/ON button.
C l e a r
Blinks
Turn off
TX-SR505/505E