HT-R557 OPERATION CHECK-2
SPEAKER PROTECT-2 (CURRENT DETECTION)
[When] 1. Exchange power transistors (Q6050 - Q6054, Q6060 - Q6064). 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.
FL display
T e st - _
Blinks
2. Press AUX button, while " Test - _ " is displayed. The unit will be in the state of " Test-4-00 ".
T e st - 4- 00
3. Repeatedly press + (TONE) button until " Test-4-35 " is displayed.
T e st - 4- 35
4. Connect the dummy load of 3 ohms to the Front L ch speaker terminals. At this time, check that the speaker relay is not turned off.
T e st - 4- 35
5. Connect the dummy load of 1 ohm to the Front L ch speaker terminals. At this time, check that the speaker relay is turned off and " Protect " is displayed.
P rotect
Disconnect the dummy load immediately after checking the display of " Protect ".
T e st - 4- 35
6. Check other channels according to the same procedure as 4 and 5. 7. Press the STANDBY/ON button.
