DVP-LS755P - Sony DVD Service Manual (repair manual). Page 67

The Self Check mode is the function to conduct the basic test to
the FL display and DVD panel section.

At the AC Power ON after reset of IF CON is released with the
MV-044 board are not connected to the IF-117 board, or while
pressing the

x

key on the main unit with the IF CON in STANDBY

mode, enter

O

(RETURN) 

→ 

[DISPLAY]

 on the remote com-

mander, and the main unit transits to the Self Check Mode.

The IF-117 board (IF CON) test mode is the IF CON self diagnos-
tic mode. The IF CON can diagnose the functions of the IF-117
board that the IF CON controls. Normally, the IF CON makes a
serial communication with the SYSTEM CONTROL and oper-
ates following the commands from the SYSTEM CONTROL, but
in the Test mode, the IF CON operates independently from the
SYSTEM CONTROL.

In the Test mode, the following functions can be checked.
1. Button function
2. Remote commander receiving function
3. SYSTEM CONTROL-IF CON serial communication
4. Fluorescent display tube lighting check

Grid check
Anode check

5. LED control function

In the Test mode, the main unit operates same as usual, except
voltage monitoring, communication monitoring, display of fluo-
rescent display tube, and LED control.
1. The routine that monitors +3.3 V (P-CONT) of MV-044 board

is not provided.

2. The monitoring timer for serial communication with the SYS-

TEM CONTROL is not provided. The main unit is not placed
in the Standby mode, even if the communication with SYS-
TEM CONTROL is normal.

3. Display of fluorescent display tube (normally, display is made

following the commands from SYSTEM CONTROL)

4. LED control (normally, control is made following the com-

mands from SYSTEM CONTROL)