Epson LQ-870 Service Manual page 96

12/4/92
5.1 OVERVIEW
Use the procedures described in this chapter to help identify problems in the printer based on the symptoms that these
problems may produce.
5 . 3
R e p a i r o f t h e
power
The following tables provide troubleshooting information.
Carriage motor
Paper-feed motor
Printhead
Error Display
Buzzer beeps 3 times for
0.1 second, with
0.1-second intervals.
Buzzer beeps 5 times for
0.5 second, with
5 - 1 4
R e p a i r o f t h e
m a i n / d r i v e b o a r d
supply board
I
The fault is corrected
5-1.
Figure
Table 51. Motor and Printhead Coil Resistance
Coil resistance - 5.0 ohms f 7% at 77' F (25' C)
CRA,
(pin 1 =
Shinano Kenshi motor:
Coil resistance - 56.0 f 4 ohms at 77" F (25' C)
Seiko Epson motor:
Coil resistance -5l.Of4ohmsat77"F(25"C)
(pin
Coil resistance - 16.7 f 2.0 ohms at 77' F (25' C) (See page 5-7 for information.)
Table 5-2. Error Codes
Error
Paper-out error
Carriage error
START
5 - 2
5 . 2
Repair by
u n i t r e p l a c e m e n t
5 - 1 6
5 . 4
Troubleshooting Procedure
Specifications
pin 2 = CR-A, pin 3 = CRB, pin 4 = CR-B, pin 5 = common)
3 = PFB, pin
Cause
Printer is out of paper.
l
Paper-end sensor is abnormal.
l
Carriage motor malIunction.
l
Carriage mechanism malfunction.
l
Carriage motor driver malfunction.
l
5-1
5 - 1 9
5 . 5
R e p a i r o f t h e p r i n t e r
m e c h a n i s m
4 = PF-B, pin 5 = common)