Yamaha RX-497 Service Manual page 11

The protection function worked due to a DC voltage ap-
pearing at the speaker terminal.
A cause could be a defect in the amplifier. If the power is
turned on with the abnormality unsolved, the protection func-
tion works in about 3 seconds to turn off the power.
DC PRT :000 Z
The protection function worked due to the temperature limit
being exceeded. Causes could be poor ventillation or a de-
fect related to the thermal sensor. The abnormal voltage is
displayed in % based on 5V as 500%. If the power is turned
on with the abnormality unsolved, the protection function
works in about 1 second to turn off the power.
TMR PRT:000 Z
For detection of each protection function (except I-PRO-
TECT) , refer to DIAG MENU No.3 AD DATA CHECK (p.13).
History of protection function
When the protection function has worked, its history is stored
in memory with a backup. Even if no abnormality is noted while
servicing the unit, an abnormality which has occurred previ-
ously can be defined as long as the backup data has been
stored.
The history of the protection function is cleared when DIAG is
cancelled by selecting PRESET RESERVED (Memory initial-
ized) of DIAG menu No.2 or when the backup data is erased.
Display during menu operation
During the DIAG operation, the function at work is indi-
cated on the FL indicator. The contents displayed dur-
ing the function operation are described later in the "De-
tails of DIAG menu" section.
Operation procedure of DIAG MENU and
SUB-MENU
There are 8 MENU items, each of which has some SUB-
MENU items.
DIAG menu selection
Select the menu using PRESET NO keys.
SUB-MENU selection
Select the sub-menu using w (Forward) and q (Reverse)
keys of TUNING.
Reverse
Functions in DIAG mode
In addition to the DIAG menu items, functions as listed
below are available.
• Input selection
• Muting
• Power on/off
• Master volume
* Functions related to the tuner is not available.
Initial settings used to start DIAG
The following initial settings are used when starting
DIAG. When DIAG is canceled, these settings are re-
stored to those before starting DIAG.
• Input: DVD
• Audio mute: OFF
• DIAG menu: DISPLAY CHECK (1. VFD CHECK)
RX-497
Forward
11