Newhaven Display Forum

Newhaven Products => OLEDs => Topic started by: markdpend on April 21, 2015, 09:40:01 PM

Title: NHD-0420DZW-AB5 Pixel Issues
Post by: markdpend on April 21, 2015, 09:40:01 PM
Hi,  The attached picture is a display about a year old.  The individual pixels are beginning to fade at random places.  Does anyone know if this is typical wearout for this technology?  Thanks in advance for any help.
Title: Re: NHD-0420DZW-AB5 Pixel Issues
Post by: Paul_B on April 22, 2015, 07:46:46 AM
Hello,

This is not typical behavior, can you please tell me how you are driving the display?

Can you also list what kind of environment this display is in?

Thanks!
Title: Re: NHD-0420DZW-AB5 Pixel Issues
Post by: markdpend on April 22, 2015, 10:05:17 AM
It's hooked up in 4-bit parallel mode.  Pins 1-2 are VSS and VDD respectively.  Pin-3 is NC.  Pins 4-5-6 are control pins RS, R/W, and E.  Pins 7-10 are NC.  Pins 11-14 are data pins DB4-DB7 driven from a Microchip PIC18F4685.  Pins 15-16 are NC.  Picture below.  VDD is 5V.  Unit is in someone's house, probably in the kitchen/eating area.

Update: I got in touch with the original owner. "It had been left in a room that was designed as a bedroom but, never used as such rather, an office.  I should say the ambient temperature in the room has consistently been fairly warm during the heating season, being in Boston.  The room is in a late 19th century building which uses a steam radiator heating system.  Even with radiators turned off, pipes going through the walls leading to other floors radiate a good deal of heat causing a steady ambient temperature of least 80 degrees."
Title: Re: NHD-0420DZW-AB5 Pixel Issues
Post by: Paul_B on April 23, 2015, 08:38:47 AM
Hello,

Thank you for the additional information. Your display appears to be hooked up correctly which is good! The fading could have been caused due to exposure of moisture.

The steam radiator heating system or having the unit placed closely to leaky doors / windows could slowly cause fading of the pixels. I recommend trying to seal the enclosure a little better just as a precaution.

Hope this helps!
Title: Re: NHD-0420DZW-AB5 Pixel Issues
Post by: markdpend on April 23, 2015, 01:33:39 PM
Thanks for taking the time to help.  Several buttons failed early too which could corroborate humidity is the culprit.  I'll see what I can do about sealing it better.
Title: Re: NHD-0420DZW-AB5 Pixel Issues
Post by: Paul_B on April 23, 2015, 02:23:34 PM
No problem, please keep us posted  ;)