Display problem - Lag-fade in menu pages and -SOLVED

[denis]

Ok I bought a digital multimeter this morning. I dont know how to use it but this is what I've done. I put the black cable to lcd pin 1 and red to 2-3. LCd contrast pot is at max.


Here are the voltages.
pin1: ground-black cable
pin2: 5.03v
pin3: 0 when contrast pot at max ; 5.03 when at min value.

http://www.hebeiltd.com.cn/lcm.datasheet/ATM1602B.doc this is the datashhet of the lcd that I use.

and a more detailed datasheet: http://64.233.183.104/search?q=cache:xg1yw2azT8UJ:www.hebeiltd.com.cn/lcm.datasheet/ATM1602B.pdf+atm1602b&hl=tr&ct=clnk&cd=1&gl=tr

[denis]

Problem seems to be related with the lcd. This morning I also bought a different lcd and recently I checked it. Problem is solved with this new lcd but there is no backlight this time, backlid is so week and can only be seen in dark.

pin 15 value: 5.03v

is it high? Can this cause the problem?


edit: new lcd's backlight is working good with 5v adapter and multimeter is reading 5.1v at adapter output. pin15 value doesnt seem to be high then.

[Synthex]

Problem seems to be related with the lcd. This morning I also bought a different lcd and recently I checked it. Problem is solved with this new lcd but there is no backlight this time, backlid is so week and can only be seen in dark.

pin 15 value: 5.03v

is it high? Can this cause the problem?


edit: new lcd's backlight is working good with 5v adapter and multimeter is reading 5.1v at adapter output. pin15 value doesnt seem to be high then.

There is a 470 ohms resistor on PCB board for the backlight.
Is your LCD already have this resistor ?

[denis]

http://www.displaytronic.com/PDF/ACM1602B.pdf this is the datasheet of new lcd. There is a resistor at + trace but I can not read the value.

[Synthex]

http://www.displaytronic.com/PDF/ACM1602B.pdf this is the datasheet of new lcd. There is a resistor at + trace but I can not read the value.

On PDF file, page 4 :
" LED Power Supply Current : 120mA " => about 40 ohms
You need to change the 470 ohms resistor on board to a 40 ohms resistor (1/2 watt).

[denis]

What about the other Lcd. Is there a way to fix the poblem on it? Cause I've fixed the old lcd to the front panel with silicon and it wil be hard to remove it=)
But if there is no way wiht it i'll detach it replace the resistor on board

[dmitri]

Is the front panel, you attached your lcd to, metallic?

[denis]

No it's plastic

[dmitri]

Could it happen that when you mounted the LCD on the front panel you somehow damaged it?
I would suggest to test this LCD with another MegaDrum again.

[denis]

I have tested it with other mega and its working ok with it that is why I thought there should not be a problem with it.
problem is kinda strange . Anyway I've already detached the lcd form panel and gonna buy some 40ohm resistor tomorrow to use with new lcd. If I can find ofcource.