cfag12864B-TMI-V Vo normal voltage and contrast testing


New member
Where is a range or a normal voltage to the Vo ?

i have a +0,6 on Vo and -2,7V to Vee but i dont display dotmatrix.

Where is the normal voltage ?
How i can test the contrast without the lpt wire connected ?

In my display i don't find any method to display white dot matrix NEVER and any software i'll try run without give me a error but no display nothing (((

I'm very afraid , i hope in you help

Sorry for bad english
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CF Support

You should have your contrast circuit as follows:

+5v to the top pin of a 10k pot
Vee to the bottom pin of the same
Wiper to Vo.

Change the contrast circuit to match that, and you should be able to invert all the pixels on the screen, provided that an early demise has not been the result of your current circuit setup.


New member
no no top pin is on Gnd,

finally i get an half result porting a components to probeboard, is strange, very strange :




is the third potentiometer :-/

Any idea to resolve it and view normal dot matrix ?