Hi, i bought a Seiko L2034 (20x4,up,down) which is using has the main controller, accordingly to it's datasheet, a KS0066U (for what i've read, equivalent to HD44780). So, in order to connect it to my paralell port i used the following schematic. Problem is that when i power up my pc (without parallel plug connected) the only thing i can see is the backlight lit, but it doesn't happen the supposed "autotest" (the 1st and 3rd line should go black, so i've read...). At first i thought it was because of the 10k POT (the one that regulates the contrast) but when i vary it, nothing happens I've checked my circuit over and over again (up,down) and everything seems accordingly with the schematic. Any help is most welcome. Thank you in advance.
Could be a faulty unit. I would start by connecting the power and contrast leads only. U should be able to do autotest with only these connections and go from there. At this point turning the contrast at the extremes should give u (a) solid bar(s).
Sorry for the delayed answer bobmister. Thank you for the tip, allready tryed it but it remains the same, must be a faulty unit has you allready said. I'm returning it to my supplyer for a refund/exchange, thanks again for your answer.
