HD44780 gets hot - voltage too high?

[ppfahl]

Hi!

I got a noname hd44780-lcd, which works fine, but gets very hot while connected to the pc's power source. when I use a external power supply, i turn it down to 4.5V and it stays cool, so maybe the 5V from the pc are too much. Is there a way to lower the pc's voltage a bit (i mean just for the lcd)?

Thanks,

Peter

[CF Tech]

Is it a backlit display? Waht you describe would be typical of a backlight being operated without a current-limiting resistor.

There is a discussion here on calculating the value for a current limiting resistor:

http://crystalfontz.com/forum/showthread.php?threadid=62