Factory Preset; Ad Data; Ps/Dc; Ps: Power Supply Voltage Protection Detection - Yamaha R-S300 Service Manual

3. FACTORY PRESET

This menu is used to reserve/inhibit initialization of the back-up IC (EEPROM: IC503 on FUNCTION P.C.B.).
3 . P R E S E T I N H I
3 . P R E S E T R S R V
CAUTION: Before setting to the PRESET RESERVED, write down the existing preset memory content of the tuner. (This is
because setting to the PRESET RESERVED will cause the user memory content to be erased.)

4. AD DATA

This menu is used to display the A/D conversion value of the microprocessor which detects panel keys and protection
functions by using the sub-menu.
When "4-3. KEY 0/KEY 1" sub-menu is selected, keys become non-operable due to detection of the values of all keys.
However, it is possible to advance to the next sub-menu by turning the "INPUT" knob.
*
Numeric values in the figure are given as reference only.

4-1. PS/DC

PS: Power supply voltage protection detection

The voltage at 93 pin (PRV) of the IC502 is displayed.
Voltage detects:
PS: ACL, AC15, ±15, +5S, +15UNREG (R model)
Normal value:
PS: 36 to 77 (Reference voltage: 5.0 V=255)
* If PS becomes out of the normal value range, the protection function works to turn off the power.
DC: Power amplifier DC (DC voltage) output is detected.
The voltage at 89 pin (PRD) of the IC502 is displayed.
Normal value: 48 to 128 (Reference voltage: 5.0 V=255)
* If DC becomes out of the normal value range, the protection function works to turn off the power.
3-1. PRESET INHIBIT (Initialization inhibited)
Initialization of the back-up IC is not executed. Select this sub-menu to protect the values set by the user.
3-2. PRESET RESERVED (Initialization reserved)
Initialization of the back-up IC is reserved. (Actual initialization is executed the next time the power is
turned on.) To reset to the original factory settings or to reset the backup IC, select this sub-menu and
press the " " (Power) key to turn off the power.
P S : 0 5 7 D C : 0 9 0
R-S300
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