STR-DN850 - Sony Audio Service Manual (repair manual). Page 10

If there is a malfunction, a message appears on 
the display panel. You can check the condition 
of the system by the message. If any problem 
persists, consult your nearest Sony dealer. 

The receiver will automatically turn off 
after a few seconds. Check the followings:

s

There may be an electrical surge or 

  power failure. Unplug the AC power cord
  (mains lead) and then plug in the cord
  again after 30 minutes.

s

The receiver is covered and the ventila-

  tion holes are blocked. Remove the object
  covering the ventilation holes of the
 receiver.

s

The impedance of the connected speakers

  is below the rated impedance range 
  indicated on the back panel of the
  receiver. Reduce the volume level.

s

Unplug the AC power cord (mains lead)

  and let the receiver cool down for 30
  minutes while performing the following
 troubleshooting:

  – Disconnect all of the speakers and 
 subwoofer.
  – Check that the speaker wires are tightly
 

twisted on both ends.

  – Connect the front speaker first, increase
 

the volume level and operate the 

 

receiver for at least 30 minutes until

 

it completely warms up. Then, connect

 

each additional speaker one by one and

 

test each additional speaker until you

 

detect which speaker is causing the 

 protection 

error.

 After checking the above items and fixing 
 any problems, plug in the AC power cord
 (mains lead) and turn on the receiver. If 
 the problem persists, consult your nearest 
 Sony dealer.

An over-current from the    (USB) port was 
detected. The receiver will automatically 
turn off after a few seconds. Check the 
iPhone/iPod or USB device, then unplug it 
and turn on the power again.

For other messages, see "List of messages 
after Auto Calibration measurements", 
"iPod/iPhone message list”, “USB message 
list” and “Network features message list”.

You can clear all memorized settings and 
restore the receiver to the factory default 
settings by the following procedure. This 
procedure can also be used to initialize 
the receiver before you use it for the first 
time.
Be sure to use the buttons on the receiver 
to perform this operation.
1. Turn off the receiver.
2. Hold down 

"/1

 (on/standby) on the 

  receiver for 5 seconds.
  [CLEARING] appears on the display 
  panel for a while, then changes to 
 [CLEARED!] 

.

s

It takes a few minutes for the memory 

  to be cleared completely. Do not turn 
  the receiver off until [CLEARED!] 
  appears on the display panel.

Be sure to use the buttons on the receiver 
to perform this operation.
  1. Turn off the receiver.
  2. Hold down MUSIC and press 

&/1

 

  (on/standby) on the receiver.
  [S.F. CLEAR] appears on the display 
  panel and all sound fields are reset to 
  their default setting.