Yamaha RX-V2065 Service Manual page 64

RX-V2065/HTR-6295
26. SERIAL
RS-232C loop back check
This menu is used to check transmission and reception of the data, and the flow port of hardware.
With the power to this unit turned off, short between pins No. 2 (RxD) and No. 3 (TxD), and between pins No. 7 (RTS) and
No. 8 (CTS) of the RS232C terminal. (Be sure to turn off the power when shorting the pins.)
Start up the self-diagnostic function and select this menu.
"OK" appears when the data is transmitted and received properly, and "NG" appears when it is not.
In this mode, NULL command transmission is continued after the test command is transmitted.
Note) Be sure to return the shorted pins to their original condition after executing this test.
EEPROM check
Communication and bus line connection between main microprocessor (IC20) and EEPROM (IC22) on the DIGITAL P.C.B.
are checked.
64
RxD TxD
1 2 3 4 5
6 7 8 9
RTS CTS
2 6 . R S - 2 3 2 C : N G
2 6 . E E P R O M : O K
OK: No error detected
NG: An error is detected