Lines 1& 2 OK 3&4 Not.....Why?

MP3IAN by Ian Gregory · 02-10-2002, 08:55 PM

I am using a powertip 40X4 (model PC4004 A) LCD with 2 x ks0066 controller chips.
I have got the first two lines to work ok but the third and fourthlines don't. The third line remians black squares and the fourth remains blank.
It is a bit funny because when i startup the computer, the LCD won't always work unless i plug it in ONLY when the PC has started???? If it is left plugged in on bootup it doesn't seem to operate. The top two rows will only turn into very faint squares.
Please Help!

PaulzY · 02-11-2002, 01:51 AM

all 40x4's have a second enable pin as they are essentialy 2(2x40)'s.

sorry i dont know which one it is i just followed the wiring diagram, if its wired correctly it may depend on what software you are using.

under 2k/xp using that port95 driver i could only get the first 2 lines working in most lcd software as they didnt accomadate for this during programming. but using lcd smartie i got all 4 lines working.

also most sofware is written for HD44780 controller type, so your chips might work differently, but looks like you missed the second enable pin as someone was going on to me about that when i was trying to get mine to work.

MP3IAN by Ian Gregory · 02-11-2002, 03:48 AM

I have the 2nd enable pin connected fine. This was the first thing i checked. I am using LCDisplayer and LCDPrint.

That still doesn't explain why the LCD will only work if i plug it in after windows has booted only! If i have i plugged in on boot it will only display very faint blocks.

why???????

PaulzY · 02-11-2002, 10:00 AM

when you say plug it in, do you mean plug the parrallel or the power connector ?

i assume u mean power connector, and thinking maby during load up it drains too much power or something? (is it powered by computer psu? are you supplying it with correct voltage?)

i dunno man, is there anythign behind the lcd to interfere with the lcd?

MP3IAN by Ian Gregory · 02-12-2002, 12:36 AM

I mean taking the whole header pin connection away from the LCD. But this problem has stopped.

The 3rd and fourth lines still don't enable.

This is really annoying. I can interface the 4X20's fine! why do "two 4X20's joined together give me so much trouble?