Sharp ER-A750, Service Manual

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3-4. Timer & Keyboard & Clerk Switch Diagnostics
The operation of the clock crystal of CKDC, the keyboard, and the
clerk switch are tested.
When the CANCEL key is pressed, the display returns to the diagnos-
tics menu.
1) Timer Check
1 Check content
The operation of the clock crystal of CKDC7 is checked.
"YY/MM/DD & MM:HH" in the display is highlighted every 500ms.
Check the highlighted display.
2) Keyboard Check
1 Check content
The A750 main body keyboard input test is performed. The posi-
tion code corresponding to the inputted key is displayed in three
digits. The key layout corresponding to the input is displayed on
the LCD screen. Press the corresponding key to input. The display
of the inputted key is changed from white square k to black square
Ç and a catch sound is generated.
3) Clerk SW Check
1 Check content
The code of the key which is inserted into the clerk key switch is
displayed in a hexadecimal number.
3-5. RS232 I/F Diagnostics
The main PWB and the option PWB (RS232 interface of ER-A7RS)
are checked. Attach the 9-pin D-Sub loop back connector (UKOG-
6717RCZZ) of wiring in Fig. 3-11.
Fig. 3-11. Wiring diagram of loop back connector (UKOG-6717RCZZ)
The following menu is displayed. The cursor position is highlighted.
Use
↑
key and
↓
key to move the cursor. Move the cursor to the
process you desire and press the enter key. The selected individual
diagnostics program is executed. When the CANCEL key is pressed,
the display returns to the diagnostics menu.
When setting channels of RS232, do not set two or more ports to
one channel. In the ER-A750, max. two units of ER-A7RS can be
installed. In each PWB, do not set two or more ports to the same
channel. If two or more ports should be set to one channel, the
hardware would be destroyed.
RS232 I/F Diagnostics
CHANNEL§Check
CH1 Check
CH2 Check
CH3 Check
CH4 Check
CH5 Check
CH6 Check
CH7 Check
1) CHANNEL Check
1 Check content
The CHANNEL setting of the connected RS232 is displayed. The
display content and the setting of DIP SW for CHANNEL setting
on the RS232 I/F PWB are compared.
Since the RS232 on the main PWB of the ER-A750 is fixed to
CH1 and CH2, that in the ER-A7RS must be set to CH3
∼
CH7.
RS232 I/F Diagnostics
CHANNEL
Check
CH1 = exis
t!
CH2 = exis
t!
CH3 = no
ne!
CH4 = no
ne!
CH5 = no
ne!
CH6 = no
ne!
CH7 = no
ne!
←
Display when channel present
←
Display when no channel
(Reference) ER-A7RS CHANNEL setting (In the table below, "1" =
SW OFF, "0" = SW ON.)
ER-A7RS CON2
S1-1 S1-2 S1-3 CHANNEL
0 0 0 Invalid
0 0 1 CHANNEL 1: Impossible to set
0 1 0 CHANNEL 2: Impossible to set
0 1 1 CHANNEL 3
1 0 0 CHANNEL 4
1 0 1 CHANNEL 5
1 1 0 CHANNEL 6
1 1 1 CHANNEL 7
Timer & Keyboard & Clerk SW Diagnostics
DATA & TIME = YY/MM/DD & HH:MM in the display is highlighted every 500ms.
KEY CODE = *** CLERK CODE = ***
CD 1pin
2pin
3pin
4pin
5pin
6pin
7pin
8pin
9pin
RD
SD
ER
GND
DR
RS
CS
CI
6 – 5