LCD 12864 contrast issue with backlight

[poodull]

Hello,

I am using a RAMPS 1.4 board with Mega and the GEEETECH 12864 lcd I bought from this guy: http://www.ebay.com/itm/LCD12864-Dots-G ... 7dc95489f0

The issue I'm having is that if the LCD backlight is on (jumper SV1), the screen is very very pale and unreadable unless tilted at a massive angle, and even then it's not clear.

If I pull the SV1 jumper (turn the backlight off), then the screen is readable -- under direct light.

The Control->LCD Contrast setting doesn't change the screen at all.

I'm using Marlin V1 firmware. The buzzer, knob and 'light' button all work fine.

Any suggestions?

Also, as a side note, I can't find any references in your wiki to SV1, R1, or R6.

[jack]

hi
i am sorry.
the volt will be 9v or high.
if your screen always light,you can change it to other side.and press key ,the screen will light 10s.