1
\$\begingroup\$

I have salvaged a colour LCD from an old Brother MFC-J6710DW printer and I'm trying to work out its pinout, to eventually use with an Arduino.

Front of panel

On the back it has the following characters printed:

COM33T3M15QLX
0L 33 CX504835
A63046001
CL 1C0L CX504835

The spacing of these characters are a bit open to interpretation, but I've done my best.

Back of panel

I've tried Googling the printer as well as the characters printed on the back but I haven't found anything of help. How would I go about working something like this out?

If its of any help, here is a picture I took of where the LCD was connected to the main logic board of the printer:

Logic board

Thanks for your help!

EDIT: @mister-tea Here's a picture with the black housing removed. No further clues I think. Tried pumping up to 5V limited at 1A with my power supply through the +/- terminals but unfortunately nothing happened. Sounds like I should give up?

No housing

\$\endgroup\$
  • \$\begingroup\$ This is unlikely to be an easy task and there is no guarantee your chosen microcontroller will be able to interface with it at the end. If the printer still works then a logic analyser on the interface would be a good place to start. \$\endgroup\$ – David Apr 23 '15 at 7:00
  • \$\begingroup\$ Maybe one an attempt to figure out which IC is driving the display and then use that to find the specs. That is if your lucky enough to find information n the driver. \$\endgroup\$ – Password Apr 23 '15 at 7:19
  • \$\begingroup\$ Totally not worth it. You could keep the polarizing films from it and use those during the next eclipse, but that's about it. An LCD from a smartphone produced en masse has a much bigger chance of having a spec on the net. \$\endgroup\$ – Dmitry Grigoryev Apr 23 '15 at 7:55
  • 1
    \$\begingroup\$ How much further can you disassemble the lcd? It appears you can pop the white housing from the black frame. Might be able to find some more clues. I also see two traces on the flexi pcb that are labeled + and - which run separately to the front. Most likely the backlight supply. \$\endgroup\$ – Mister Tea Apr 23 '15 at 12:12
  • 1
    \$\begingroup\$ Can I point out that these kinds of displays are dirt cheap on eBay. Plus they often even come with semi-translated Chinese manuals. Trying to physically connect to the ribbon cable of your display alone could be a headache. \$\endgroup\$ – CL22 Apr 24 '15 at 13:32
3
\$\begingroup\$

A search for "Brother MFC-J6710DW repair guide" dug up this link. That is a service manual for your printer.

Chapter 6 (Circuit diagrams and wiring diagrams) shows the 25 pin connector to the LCD, and gives signal names for all of the signals on that connector. Looks to me like the data is written to the LCD in parallel - there are 8 lines marked "DB" which I take to mean "data bus."
Some of the pins with question marks will be used to regulate who can write/read the data bus, and some will be used to get the attention of the other end of the line (LCD can signal main processor, processor can signal LCD.)

What the data on the databus actually means is a whole other can of worms.

The connector pinout is, with some guessing at the meaning of the signals:

  1. BLL - backlight low (?)
  2. BLH - backlight high (?)
  3. NC - not connected (?)
  4. GND
  5. RDB - read (active low?)
  6. GND
  7. WRB - write (active low?)
  8. GND
  9. RS - ?
  10. GND
  11. CSB - chip select (active low?)
  12. GND
  13. DB10 - data bus bit 0
  14. DB11
  15. DB12
  16. DB13
  17. DB14
  18. DB15
  19. DB16
  20. DB17 - data bus bit 7
  21. GND
  22. FMARK - frame marker (?)
  23. VCC - (3.3 or 5V?)
  24. VCC
  25. RESET - LCD controller reset (active low ?)

A search for similar chips and pin designations turned up the ST7036, which is probably NOT the chip on your board, but it might help to read its data sheet and see if it can give you any pointers, or at least more information so that you do more directed searches.

There seem to be several more or less common types. This Arduino forum mentions the ST7036 as well as different type - perhaps some of the existing code will help you, or maybe you will be able to find out whta chip is on your board and find some arduino code that supports it directly. Your pictures are unfortunately too fuzzy for me to identify.

\$\endgroup\$
  • \$\begingroup\$ Holy blood hound batman. Nice search fu \$\endgroup\$ – Passerby Apr 24 '15 at 15:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.