ER-A880 (serv.man2). ERA850 880 Service Manual - Sharp EPOS Service Manual (repair manual). Page 20

2

Display

LPT2 Loop Check

ACK- Signal

:

PASS !! (or ERROR !!)

BUSY Signal

:

PASS !! (or ERROR !!)

PE Signal

:

PASS !! (or ERROR !!)

SLCT Signal

:

PASS !! (or ERROR !!)

ERROR- Signal

:

PASS !! (or ERROR !!)

STROBE- Signal

:

PASS !! (or ERROR !!)

AUTOFD- Signal

:

PASS !! (or ERROR !!)

INIT- Signal

:

PASS !! (or ERROR !!)

SLCTIN- Signal

:

PASS !! (or ERROR !!)

INTERRUPT

:

IRQ X (or ERROR !!)

DATA Bus

:

PASS !! (or ERROR !!)

"XX" shows the interruption level.
If LPT2 is not accessible, the display shows the following.

LPT2 Loop Check

LPT2 Channel Disabled

3

Exiting
Pressing the Esc key will exit from this check mode.

1

Check contents
Loop check is performed to LPT3 at I/O address 3BCH 

∼

 3BEH.

To perform the loop check, insert an ER-A8RS to be checked to
the extension slot, insert another ER-A8RS which is operating
normally to another slot, and connect the loop cable as shown in
Fig. 3-3.  For the jumper setting on the PWB, refer to Fig. 3-6.

Fig. 3-6 Jumper pin setting

The test procedures are as follows:

i.

Data 55H is written into I/O address 3BCH, and the same
address is read. If the read data is not 55H, "LPT3 Disabled"
is displayed and the following procedures are not performed.

ii.

Data 01H is written into I/O address 37AH, and data at I/O
address 3BDH is read. If the read data is 47H, "AC-Signal
OK" is displayed. If not, "AC-Signal ERROR" is displayed.

iii.

Data 02H is written into I/O address 37AH, and data at I/O
address 3BDH is read. If the read data is 87H, "BUSY Signal
OK" is displayed. If not, "BUSY Signal ERROR" is displayed.

iv. Data 04H is written into I/O address 37AH, and data at I/O

address 3BDH is read. If the read data is 37H, "PE Signal OK"
and "SLCT signal OK" are displayed. If not, "PE Signal ER-
ROR" and "SLCT Signal ERROR" are displayed.

v.

Data 08H is written into I/O address 37AH, and data at I/O
address 3BDH is read. If the read data is 0FH, "ERROR-Sig-
nal OK" is displayed. If not,  "ERROR-Signal ERROR" is dis-
played.

vi. Data 01H is written into I/O address 3BEH, and data at I/O

address 379H is read. If the read data is 47H, "STROBE-Sig-
nal OK" is displayed. If not, "STROBE-Signal ERROR" is dis-
played.

vii. Data 02H is written into I/O address 3BEH, and data at I/O

address 379H is read. If the read data is 87H, "AUTOFD-Sig-
nal OK" is displayed. If not, "AUTOFD-Signal ERROR" is dis-
played.

viii. Data 04H is written into I/O address 3BEH, and data at I/O

address 379H is read. If the read data is 37H, "INIT-Signal
OK" is displayed. If not, "INIT-Signal ERROR" is displayed.

ix. Data 08H is written into I/O address 3BEH, and data at I/O

address 379H is read. If the read data is 0FH, "SLCTIN-Signal
OK" is displayed.

x.

Data 10H is written into I/O address 3BEH to generate an
interruption. If an interruption is generated, the interruption
level is displayed. If no interruption is generated, "Interrupt
ERROR" is displayed. After confirmation of an interruption,
data 00H is written into I/O address 3BEH.

xi. Data 55H is written into I/O address 3BCH, and data at I/O

address 378H is read. If the read data is 55H, the next check
is performed. If not, "DATA Bus ERROR" is displayed.

xii. Data AAH is written into I/O address 3BCH, and data at I/O

address 378H is read. If the read data is AAH, "DATA Bus
OK" is displayed. If not, "DATA Bus ERROR" is displayed.

2

Display

LPT3 Loop Check

ACK- Signal

:

PASS !! (or ERROR !!)

BUSY Signal

:

PASS !! (or ERROR !!)

PE Signal

:

PASS !! (or ERROR !!)

SLCT Signal

:

PASS !! (or ERROR !!)

ERROR- Signal

:

PASS !! (or ERROR !!)

STROBE- Signal

:

PASS !! (or ERROR !!)

AUTOFD- Signal

:

PASS !! (or ERROR !!)

INIT- Signal

:

PASS !! (or ERROR !!)

SLCTIN- Signal

:

PASS !! (or ERROR !!)

INTERRUPT

:

IRQ X (or ERROR !!)

DATA Bus

:

PASS !! (or ERROR !!)

"XX" shows the interruption level.
If LPT3 is not accessible, the display shows the following.

LPT3 Loop Check

LPT3 Channel Disabled

3

Exiting
Pressing the Esc key will exit from this check mode.

1

Check contents
Print check is performed to LPT1 at I/O address 378H 

∼

 37FH.

For print check, set the short pins of the ER-A8RS to be checked
as shown in Fig. 3-7, connect the D-Sub 25-pin connector to the
printer, and set the printer ready for print check.

Fig. 3-7 Jumper pin setting

The test procedures are as follows:

1
2
3

J1

9

1

0

J4

J3

1
2
3

J1

9

1

0

J4

J3

Setting ER-A8RS to be checked

Setting ER-A8RS to check

1
2
3

J1

9

1

0

J4

J3

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