I've seen this before, in cases where the pin-3 voltage wasn't properly set. What does the LCD datasheet say the device requires?

The safest hookup for this, apparently quite conventionally pinned-out LCD's PIN 3 contrast bias voltage, which allows for the widest range of options, would be a potentiometer of, say, 10 k-ohms with a 1 k-ohm resistor at each end (just to keep it from going to the rails) and the wiper of the potentiometer to that pin to which you refer as Vee. That will enable you to alter the voltage to either a positive or a negative voltage. The Potentiometer and its associated fixed resistors should be fixed between Vdd and a Vee of -5 volts. That way, no matter what the actual demand of your LCD is, you have a reasonable chance of getting there. If you have a MAX232 or similar device in your circuit, you might try using the V+ and V- terminals from it. Normally, the current requirement on this coontrast bias supply is very small.

Read the LCD datasheet before making any changes.

RE