Boot State Time


New member
Is there a way to set the 635 model LCD to display the Boot Text etc. Untill the host software is ready. Right now when plug in the LCD it will show the boot screen for a couple of seconds then turn off untill I launch a third party program.

I also notice that when I use the test utility(windows) to access the LCD I can change the display contrast and back light settings only but it will not let me send any text lines (Command 31) unless I was to close the test program, lauch a 3rd party program(lcdsmartie) then after I close it and open up the LCD test program then I can send Text. Not sure what I am missing.

Not sure if this helps I ordered the 635 lcd with the SCAB and the ATX power/WOL cable. and noticed it was presetup for me (soldered jumper etc)

Thanks for your time and Happy Holidays
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Last edited:

CF Tech

The CFA-635 should leave its boot text up by default.

I think there must be some software talking to the display.

Try booting in safe mode and seeing if the text still disappears.


New member
I seem to be having this same issue. Green 635 powered through the SCAB, the CrystalFontz factory power on screen will show for about a second then the screen will blank (LED0 stays green). I can control the backlight and contrast via my program but it will not display any text. The CF boot screen does not stay on the LCD even when I unplug the USB cable before powering on, so I know it is not receiving any commands. BTW I am using linux, I have a blue 635 that is powered by USB that works perfectly with my program (normal boot screen, responds to all commands, etc).
Here are the jumper settings for the 635 I am having problems with. I should also note that I had another green 635 set up on the same computer with the same program and the same SCAB and it was running fine, however, it met with an untimely demise and this new green one is a replacement. Like crees I ordered this one with the ATX power/WOL cable. Not sure if that makes a difference, I dont have the ATX power cable plugged in though as the SCAB is not jumpered correctly for it yet. It just receives power from the FDD power cable.

635 jumpers:
JPA2 - closed
JPB2 - open
JPB1 - open
JPA1 - closed
JP2 - open

SCAB jumpers:
JP8 - closed
JP9 - open
JP16 - open