Z-World Fox LP3500 User Manual - page 93

User’s Manual

87

C.2  Contrast Adjustment

Depending on when you acquired your LCD/keypad module, you will be able to set the 

contrast on the LCD display by adjusting the potentiometer at R2 or by setting the voltage 

for 2.8 V by setting the jumper across pins 1–2 on header J5 as shown in Figure C-3. Only 

one of these two options is available on a given LCD/keypad module

Figure C-3.  LCD/Keypad Module Contrast Adjustment

NOTE:

Older LCD/keypad modules that do not have a header at J5 or a contrast adjust-

ment potentiometer at R2 are limited to operate only at 5 V, and will not work with the 

LP3500. The older LCD/keypad modules are no longer being sold.

C2

R2

R1

C3

D2 C1

D1

C5 U2

JP1

R3

U1

C4

C10

CR1

R6

C13

C12

R7

R8

R25

R26

R11

R13

R14

R10

R9

R12

R15

R18

Q8

R16

Q5

R21

Q2

U5

J2

DISPLAY

BOARD

J4

KP1

R17 Q4

R22

Q6

R23

Q7

R20

Q3 R19

U7 C14

R24 C15

C16

U6

U4

C7

C9

U3

LCD1

C11

R4

R5

C6

J1

Q1

J5

C17

RN1

J5

LP3500

2.8 V

OTHER

3.3 V

1

2

3

4

n.c. = 5 V

LCD/Keypad Module Jumper Configurations

Header

Description

Pins

Connected

Factory

Default

J5

2.8 V

3.3 V

5 V

1–2

3–4

n.c.

×

J5

1

2

3

4

Part No. 101-0541

Contrast

Adjustment