Newhaven Display Forum

hello,
I'm using a OLED character display (NHD-0420CW-AB3) for a R n D project. but I have a problem of burn in images were displayed on some parts of the display screen. I have changed the contrast to the lowest value using the command but the problem occured. Also the lowest contrast also too high. we are going to buy some bulk quintity. but the issue is the burn in images occured for a few month of time interval since first use. How can we control the life time of pixels evenly and is there any solution or recommendations to solve that.also we need more control o the brightness of the display. Thank you.

Thanks for the swift reply!

The voltage for VDD is 3.3V in my circuit. The microcontroller also operates on 3.3V so all communications are at the same voltage too.

The backlight is on the same supply. I'm using a 50 ohm current limiting resistor as I didn't need the back light too bright.

I probed the supply rail with an oscilliscope before and after the problem started - Before, the voltage was clean and steady. After, VCC is pulled down by ~.3V almost everytime commands/messages are clocked onto the datalines. I saw this behavior even with the ISP connected which has a very significant power source available (i think it can supply something like 1A?) 

Cheers,

Hey all,

I've been prototyping with a few 16x2 character 3.3V displays (NHD-0216HZ-FSW-FBW-33V3C) and had some unusual behavior with contrast.

The display starts out great (good contrast and sharp characters, etc) but after a few mins of use and a little bit of handling, power on/off cycles, etc, I'm finding the contrast starts acting funny.

All the pixels start to fade in a random pattern/gradient, totally non-uniformly distributed across the whole display. At times, it becomes so light that it is hardly visible. Power cycling does not fix the issue, nor does resetting the microcontroller i'm using to drive the module.

Per the datasheet, pin 3 (typically contrast) is listed as NC, so I've left if floating. there is no contrast pin listed so presumably it's a fixed contrast design? Could anyone confirm that pin 3 should float on this specific part number?

I'll add a picture to this post to show what i'm seeing, check it out.

Here is some background info:
1. LCD is mounted to a panel and wired to a breadboard

2. I'm using 4-bit mode and getting everything I want to show up on screen, so the issue does not appear to be caused by code or wiring on data lines.

3. The backlight is illuminated and steady, no flickering.

4. I've considered the refresh rate of my code, this issue persists with static displays.

5. 2x units have shown this behavior, first one acted up soon after plopping down onto a table, second one started when a hot ISP programming header was de-mated, removing power. Perhaps it's something to do power being removed midway thru communications with the MCU? or an interrupted VCC or GND connection? is it likely a power interruption would cause damage that creates these symptoms?

6. I measure 0.23V on pin 3 in the latest unit showing this issue.

I will look into it. Thanks!

I have sent you an email with the 3D model of this display.  We will be adding it to our website for future reference.

Best Regards,