Chapter 1 : Beginning
6 years ago. I got the old CD car player made by SONY. It’s CDX-GT700D and this CD car play having such a fascinating feature. That is the Graphical Display with the the Blue-ish like 488nm laser ! So I don’t delay de-solder-ed that day. removing the display and thrown the rest panel board, leaving only bare Display. It’s turned out to be Vacuum Fluorescent Display or VFD .
Here’s the demo :
Chapter 2 : Hunting Haunted
Year later, I just finding old stuffs that I have and found this Display, I took it from the box and start looking at the back of the display. Then I noticed the the weird shiny brand “Noritake itron JAPAN” and marking MN15439A on the opposite side (We’re still on the back).
then I googled this up but found nothing, I start by going to the Noritake Itron ‘s Website in the VFD section also found nothing, but at that time (Grade 8) my English skill isn’t great likes today, So I gave up on that. Then I contacted to one of employee by the contact email on their website. They said
Dear classified name / Thailand
The P/N : MN15439A is designed for particular customer.
Unfortunately we can not open any of the information
about this exclusive customer.
Thank you for your understanding.
OK. Not what I expected though …
Another year passed still no clue what the heck is this stuff, I went to their website again to grab the similar display’s datasheet and compare with this SUCKER (oops, little explicit xD). and I draw the pinout of the MN15439A (At then, I guess that it’s right, and absolutely YES!) not exactly remember what display is used as reference (possibly MN14440A or MN14416A). back then my hand writing still sucks as right now lol.
Chapter 3 : Electrically thinking
Everyday I went to school, And I known one teacher (who used to be an adviser of friend’s school project) He is the top form in Electronics, He design his own switching power supply, making his own Sumo robot and a lots more of electronics things (including Microprocessor/controller this from ASSEMBLY to BASIC and C/C++). I ask him for some help for how to correctly drive the Display’s filament heater (electron shooter) and he said that it both works with DC and AC at about 3.3 volt (which is right). Big thanks to him. but unfortunately He passed away 2 years ago (2018) due to cancer. but his wife told me that he’s very smart guy but since he was teacher. He works hard and some day he doesn’t event come back home, his wife said. Anyway don’t be sad -> Lets dig deeper
Today, I decided to write this blog (2020/5/1) because something just hit my brain and telling me to pick this old display up along with my GU280x16G-7000 from project FakeGrayscale. I start to search again after 6 years. Now I have the better English language that 6 years ago (I believe xD). I went to [Noritake Itron] website again to download ALL of datasheet that available for downloading. Finally found two that having exactly same pin number are the MN14440A and MN14416A. . But I’m skeptical that the custom made likely having entirely different pinout. new Idea just pooped up in my head. I quickly go to google my activities site and use keyword CDX (that What I remember) and the “CDX-GT700D” trigger my memory. quickly search for service manual.
Chapter 4 : Reveal the truth
Good luck, I found the service manual online and download them, surprisingly found the PCBs and Schematics. And boom !!! the Display PCBs
The first page of service manual :
PCB layout :
YEAHHHHHH. Finally. after 6 years of finding. It’s here ! The MN15439A
Comparing with the actual thing :
Great match, After that I took some look at my drawing from many years ago and I was right back then.
Chapter 5 : What’s next ?
*at this point. I forgot to tell you that the MN15439A uses the Chip In Glass – CIG Technology by putting few shift register on the glass inside display. Each shift register has hundreds of bits (up to 288 bit !)*
reaching this part. I’ve mad a plan to design the 50-ish VoltDC boost converter for the VFD and do some code with STM8L (seriously ?!?!?). I will include the links to the display I used as the pinout reference (which is match) and some more details of that display.
All the data I used is here.
MN14440A – brief datasheet , MN14440A full datasheet , CDX-GT700D service manual