Sharp ER-A520 Service Manual page 20

13) CPU INTERNAL RAM TEST
1 Key operation
122 3
CA/AT
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
OP display
C P U R A M
1 2 2
3 Check:
The completion print.
4 End of testing
The test program ends after printing.
When the test ends normally:
When the test ends abnormally:
x = 1: Data error
x = 2: Address error
If an error occurs, the printer outputs the error message and the
address where the error has occurred in the area ***** .
14) FLASH ROM TEST
1 Key operation
130 3
CA/AT
2 Test procedure
The test program checks that the checksum of the flash ROM
(F00000H ~ FFFFFH).
The lower two digits of the checksum should be 10H. (pending)
OP display
F L A S H
1 3 0
3 Check: The completion print.
4 End of testing
The test will automatically be terminated and the printer prints as
follows:
When the test ends normally:
ROM
When the test ends E – – ~ – –
abnormally:
ROM
S R V
122
Ex – ~ – 122
*****
S R V
R O M
130
******** (Model name)
******** (Version)
130
******** (Model name)
******** (Version)
ER-A520U/ER-A530U DIAGNOSTIC PROGRAM
15) AD CONVERSION PORT TEST
1 Key operation
160 3
CA/AT
2 Test procedure
The test program displays the voltage of each AD conversion port.
Display
OP display
T M
1 6 0
Repeat
OP display
V R F
1 6 0
OP display
V P T E S T
1 6 0
3 End of testing
You can exit the test mode by pressing any key. The printer prints
the following.
1 6 0
16)POLE DISPLAY TEST
UP-P16DP is attached in DISPLAY CN.
1 Key operation
400 3
CA/AT
2 Test procedure
Displayed in the following procedure A test pattern.
Progresses to the following pattern by pushing arbitrary KEY.
i ) The following test pattern is displayed.
DOT DISPLAY :
7SEG DISPLAY :
ii) The test pattern of all beam all-points lights is displayed.
3 Check:
A) The display of each position is right.
B) Be uniform in the luminosity of each display and there needs to
be no MURA in it.
4 End of testing
You can exit the test mode by pressing any key. The printer prints
the following.
4 0 0
17) RS232 CH1 TEST
Install the RS232 loopback connector.
1 Key operation
500 3
CA/AT
2 Test procedure
The test program checks the control signals.
OUTPUT
/ER1 /RS1
OFF OFF
OFF ON
ON OFF
ON ON
– 19 –
=
S R V
=
S R V
=
S R V
0 1 2 3 4 5 6 7 8 9 ; A a B b C
0 . 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . - .
c c c c c c c c c c c
INPUT
/DR1 /CI1 /CD1
OFF OFF OFF
OFF OFF ON
ON ON OFF
ON ON ON
/CS1
OFF
ON
OFF
ON