Sharp ER-A420 Service Manual

ER-A410/ER-A420 DIAGNOSTIC PROGRAM
– 18 –
12) CPU INTERNAL RAM TEST
1 Key operation
121 3
2 Test procedure
The test program tests internal RAM (10 Kbytes) of the CPU.
The contents of memory must be stored before and after this test.
RAM (00400H ~ 02BFFH area) is tested in the following procedure.
a) Store data in the test area.
b) Write “00H”
c) Read and compare “00H” and then write “55H”
d) Read and compare “55H” and then write “AAH”
e) Read and compare “AAH”
f) Restore stored data
If an error occurs at a step, the error is printed.
If any error does not occur, the following addresses are checked
in turns.
Addresses to be checked:
01000H, 01001H, 01002H, 01004H, 01008H
01010H, 01020H, 01040H, 01080H,
01100H, 01200H, 01400H, 01800H,
02000H
3 Check:
The completion print.
4 End of testing
If an error occurs, the printer outputs the error message and the
address where the error has occurred in the area *****.
13) FLASH ROM TEST
1 Key operation
130 3
2 Test procedure
The test program checks that the checksum of the flash ROM
(BANK0F80000H ~ FFFFFH).
The lower two digits of the checksum should be 10H. (pending)
3 Check:
The completion print.
4 End of testing
The test will automatically be terminated and the printer prints as
follows:
14) AD CONVERSION PORT TEST
1 Key operation
160 3
2 Test procedure
The test program displays the voltage of each AD conversion port.
3 End of testing
You can exit the test mode by pressing any key. The printer prints
the following.
160
15) RS232 CH1 TEST
Install the RS232 loopback connector.
1 Key operation
500 3
2 Test procedure
The test program checks the control signals.
Data communication check
A loopback test of 256-byte data between is performed.
DATA: $00 - $FF BAUD RATE:9600 BPS
3 Check:
The completion print.
4 End of testing
The test program ends after printing.
When the test ends normally: 121
When the test ends abnormally: Ex – ~ – 121
*****
x = 1: Data error
x = 2: Address error
When the test ends normally: 130
ROM
********
(Model name)
********
(Version)
When the test ends
abnormally:
E
– – ~ – – 130
ROM
********
(Model name)
********
(Version)
TL
RAMCPU
SRV
OP display
121
TL
ROMFLASH
SRV
OP display
130
OUTPUT INPUT
/ER1 /RS1 /DR1 /CI1 /CD1 /CS1
OFF OFF OFF OFF OFF OFF
OFF ON OFF OFF ON ON
ON OFF ON ON OFF OFF
ON ON ON ON ON ON
Completion print RS TEST OK
Error print RS TEST **NG**ERxx
xx Contents of error
01 ER DR error
02 ER CI error
03 RS CD error
04 RS CD error
05 SD RD error DATA error
06 SD RD error DATA error/framing error
TL
TM
SRV
OP display
Display
160
=
VRF
SRV
OP display
160
=
VPTEST
SRV
OP display
160
=
Repeat
TL
RS TEST
SRV
OP display
500
232

Sharp ER-A420 Specifications

General

Product color	White

Weight and Dimensions

Weight	12200 g
Dimensions (WxDxH)	355 x 424 x 305 mm