Repairing or replacing an LMB202E LCD Display

[subwagon]

Hello everyone, I'm in the process of repairing a tabletop air cleaner, but am having difficulty repairing a failing LCD display.

3 years ago I ran a soldering iron over the ribbon cable and got the entire display to come back to life. Unfortunately it gradually failed again but this time I wasn't so lucky at getting it to revive with heat.

I believe that I may have gotten the ribbon too hot this time, so I'm looking for an alternative to an LMB202E. Unfortunately I am not having much luck. I did find an LMB202A, LMB202C, and LMB202D but I'm afraid the pin outs are not going to match up and I don't have a logic analyzer to identify the 16 pins coming out of the control board to the LCD board.

Looking all over the internet for a replacement the only mention I found for this part number was for a repair done on an identical model to my air cleaner. But the page is in Russian and I'm not following what the pin out was to convert to the alternative display used. (https://www.axgxp.pro/2021/11/fresh-air-2021.html?m=0)

It also looks like the above mentioned repair hard wired the LCD board to the control board and id like to try and keep it modular for future repairs if I can.

So, any tricks on saving bad LCD displays?
or any good ideas on alternative display options?

Also if any one is wondering its a display being used on an EcoQuest - Fresh Air 2.0

Thanks!

[petehall347]

Re: Repairing or replacing an LMB202E LCD Display

right click and translate .

[subwagon]

Re: Repairing or replacing an LMB202E LCD Display

right click and translate .

yes, mentioning it was in Russian was for the benefit of the audience if they went to check out the link. I ran google translate and I'm still not following what pinout was used to transition to the display this gentleman used.

And I'd also like to poke around and find a direct one to one replacement that shares the same pin out if I can, instead of hard wiring like in the link above.

[petehall347]

Re: Repairing or replacing an LMB202E LCD Display

i thought i saw a list of what pinouts do

[subwagon]

Re: Repairing or replacing an LMB202E LCD Display

i thought i saw a list of what pinouts do

Yes you did! It was for the LMB202E's manufacturer Data sheet. Not sure what I was thinking earlier, lol. Simply pinned out a spare LCD to match the Pins from the Data sheet and it lit right up. Looks like there isn't a direct replacement for the LMB202E, so instead I'm picking up a Blue with white LCD to go in its place. I used a great big display I had laying around but ordered a nice 20x2 character LCD that has the same dimensions as the old LMB202E.

1. Led Backlight Positive Power Supply
2. LED Backlight Negative Power Supply
3. VSS 0V Power supply, Ground
4. VDD Positive Power Supply
5. V0 LCD Contrast Refrence Supply
6. RS Register Select High or Low
7. R/W Read Write Control (Write = High)
8. E Data Enable
9. DB0
10. DB1
11. DB2
12. DB3
13. DB4
14. DB5
15. DB6
16. DB7

Now he threw in some resistors, and also didn't end up using all the pins on the board driving the LCD. In my case I wired up my Display according to the Pinout from the LMB202E as it had a 1 to 1 connection to the Driver board this would mean that the Driver board would have the same pin out. And everything worked out. In fact, I suppose the use of an analyzer would not really be needed as the pin out was already available from the display manufacturer.

Thanks Pete, Guess I just needed to bounce the Idea off someone for it to click in my head.