635 driver problem


New member
Well, after spending hours on modifying a nice metal box for my 635 with bracket. I plug it back into my usb port, the same one I removed it from, and it says "unknown device." I then spent about an hour or so just getting frustrated, because it's still an "unknown device." I tried removing anything CF I could find, I tried deleting all grayed out devices in the device manager and then reinstalling everything and then plugging the 635 back in. "Unknown device"

This is really upsetting. Why does a USB device have insane issues like this?

Anyhow...any help would be much appreciated. Otherwise I have a $70 paperweight.
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USB LCD Displays - Graphic and Character LCDs with a Keypad


New member
I have had similar issues with other usb devices. Usually it works if you do this:

First Unplug all USB Devices from your PC (anything usb needs to be unplugged). Then restart your PC. Try then plugging in items again to see if you can get to the screen with it working. If you still get the same error, unplug all usb devices again. Then in device manager remove all the usb root hubs and devices. Restart the pc and you will have to reinstall these items (for most mainboards, these drivers are in windows automatically). Then hopefully it will work

CF Tech

If you cannot get it going, you might have damaged the display. Write support{at)crystalfontz(dot}com (edit to '@' & '.') and we can see about repairing it for you.


New member
My mistake! I should have posted when I fixed it. I found that the connector had loose wires. Enough so that when the cable into the lcd was moved or jiggled, the signal was messed up.

I have since fixed this. Thanks for the posts and time.