Characters not displaying on 634


New member
I installed the 634 on my computer and have double checked the serial and power connectors. I know that the power is working because the LCD backlight flashes while Windows is booting up. I've tried various drivers, but nothing seems to be able to activate either the backlight or the actual characters on the screen. Right now, the screen is just blank. Any help on what to check next would be greatly appreciated. Thanks.
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New member
Baud rate

Okay. I've figured out what the problem was. The LCD is currently using the 19200 baud rate. How can I change this to use 9600 baud instead?
USB LCD Displays - Graphic and Character LCDs with a Keypad

CF Tech

There are two small switches on the back of the LCD. There is also a table that indicates how the switches affect the baud rate. Please set the switches to match your software (or the software to match the switches :))

The display will show the selected baud rate for a few seconds at power up, unless you have changed the boot screen or closed JPK.