Onkyo TX-SR504 Service Manual page 3

OPERATION CHECK-1
SPEAKER PROTECT-1 (DC VOLTAGE DETECTION)
[When]
1. Exchange power transistors (Q6050 - Q6056, Q6060 - Q6066).
2. Exchange amplifier PC board ass'y (NAAF-8779).
[Procedure]
<Note>
No load. No input.
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 VIDEO 3 button while the characters of " Test - _ " are 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 the characters of " Test-4-21 " are displayed.
T e s t - 4 - 2 1
Check whether the operation starts and continues automatically as follows.
T e s t - 4 - 2 1
P r o t e c t O K
T e s t - 4 - 2 2
P r o t e c t O K
T e s t - 4 - 2 3
P r o t e c t O K
T e s t - 4 - 2 4
P r o t e c t O K
If all channels are OK, the characters of " Test-4-35 " are displayed.
T e s t - 4 - 3 5
4. Press STANDBY/ON button.
Blinks
Front L ch
Check
Front R ch
Check
Center ch
Check
Surround L ch
Check
C l e a r
T e s t - 4 - 2 5
P r o t e c t O K
T e s t - 4 - 2 6
P r o t e c t O K
T e s t - 4 - 2 7
P r o t e c t O K
P r o t e c t
Turn off
TX-SR504/504E/8450
Surround R ch
Check
Surround Back L ch
Check
Surround Back R ch
Check