Olivetti ECR 7900 Service Manual page 51

PRINTER CIRCUIT
SHVP
0.1uF
nDATA
nDATA
HC LK
HCLK
HLATCH#
HLATCH#
STB 2#
STB2#
STB 1#
STB1#
(2)
VCC3
C2
0.1uF
R_SHTH
U5A
2 1
R_HDUP
U5 B
SN74LV14APWR
4 3
R_PEND
SN74LV 14AP WR
(3)
Motor +
Motor -
PH1
PH3
PH2
PH4
Trouble shooting
- Cannot print, or cannot Feed paper.
Check voltage (AC +7.6V) at point (1).
If it outputs properly - - - Replace Main board or printer.
If it doesn't output properly - - - Check Power supply circuit. (P.9-11)
- Faded print, or run print. - - - Replace Main board or printer.
- Cannot cancel Head-up sensor error.
Check voltage at point (2).
If DC+5.0V is properly output - - - Replace Main Board.
If DC+5.0V is not properly output - - - Replace Printer.
- Cannot cancel Paper-end sensor error.
Check voltage at point (3).
If DC+5.0V is properly output - - - Replace Main Board.
If DC+5.0V is not properly output - - - Replace Printer.
- Head-up sensor or Paper-end sensor does not work. - - - Replace Main board and pri
nter.
Y108540-8
VCC5
VCC5
C3
U14
2 18
R122
1A 1 1Y 1
4 16
R123
1A 2 1Y 2
6 14 R124
1A 3 1Y 3
8 12
1A 4 1Y 4
11 9 R125
2A 1 2Y 1
13 7 R126
2A 2 2Y 2
15 5
2A 3 2Y 3
17 3
2A 4 2Y 4
1
1G
19
2G
TC 74VHCT244FT VCC3
16K_F
R120
VCC5
R89 10K
R141 47K
PH1
PH3
PH2
PH4
ECR 7900 Service Manual
C74
*470pF
100 DAT_IN
100 CLK
100 LATCH#
100 P_DST2#
100 P_DST1#
P_TH
HS
PS
VCC3 VPRN
C5
0.1uF
U4
0.1uF
1 4
C6
VCC VS1
2 11
IN1 VS2
6 8
IN2 VCONT
13 3 A
IN3 OUT1
9 5 /A
IN4 OUT2
7 12 /B
GND1 OUT3
14 10 B
GND2 OUT4
LB 1836M
R121
15K_F
R132
5.1K_F
R133
220
C7 C75
0.1uF 470pF
VPRN
(1)
VCC5
EC 9
47uF_16V
C4
VCC5
0.1uF
CN6
TH
9
VDD
8
CLK
7
6 VP
5 HS
VPS
4 VPS
PS
3
2
1
52147-0910
CN7
13
GND
12
11 DS T2#
10 DS T1#
GND
9
8
VP
7
GND
6
5 GND
4 /A
B
3
A
2
/B
1
52147-1310
45