Tx LED

DS3

Busy LED

DS4

Batt LED

DS5

R8

C2

R9

C7

HR2

R3

 

C5

C6

R18

R7

C4

HR3

HR1

 

DS7

DS2

R14

R12

R16

C3

R17

DS6

DS8

R2

IC1

 

DS1

C1

 

R11

Q2

R15

 

 

R13

Q3

R1

 

 

Q4

Q1

GND KEYR3

KEYR2

KEYR1 KEYR0

KEYS3 KEYS2

KEYS1 KEYS0 GND

2

20

J2

GND GND SPE SPE SP

SP

L5V

DISSO

DISSK

DISST

DISEN

KEYS0

KEYS1

KEYS2

KEYS3 KEYR0

KEYR1

KEYR2

KEYR3

TXLED

BSYLED

BATLED

BKLED

GND

MICE

MIC

GND

GND

GND

29

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

 

 

 

J1

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

 

19

MIC

MICE

GND

GND

BKLED

L5V

GND

GND

SP

SPE

DISPLAY BOARD BOTTOM VIEW

DISPLAY BOARD TOP VIEW

November 1999

8-8

Part No. 001-7780-500

Page 108
Image 108
EFJohnson 7780 service manual Display Board Bottom View, GND KEYR3 KEYR2 KEYR1 KEYR0 KEYS3 KEYS2 KEYS1 KEYS0 GND