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Help with faded LCD display

axrusar

Jun 12, 2022
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Hello guys.
I am looking for some help / tips / ideas to fix a module with an LCD display.
I do have very basic understanding of electronic components, so please be super easy with the answers :p
Please check the attached images of the part i need to fix.

This is an intercom unit. Discontinued product.
I have been trying to reach the manufacturer, dealers, ebay sellers, online sources to no avail. So i am just trying to fix it myself if i can. Replacing the whole intercom unit just because the LCD is faded is very expensive and not an option.

What i tried so far..
I watched several video tutorials on YouTube on how to fix an LCD display.. so i took the LCD apart, removed the zebra strips, LCD glass part, and cleaned the contacts with alcohol on both sides of the zebra ribbons, the glass where they make contact and the metallic contacts on the board. I did this 3 times already and no luck.
I tried pressing around the edges of the metallic frame with my fingers looking to get all the digits to light up, adjusting the position and tension of the metallic frame that holds the pieces together, but i could not find a point where the digits show 100%.

This intercom is exposed to the sun and weather all year round.

There is also a contrast adjustment screw on the main board of the intercom, but it did not help to get the missing bits back.

So maybe there is a way to buy the LCD glass and zebra stripes at some electronic component dealer online that you may suggest, but i have absolutely no clue what to look for nor specifications of the LCD i have here, besides the measurements i am showing in the pictures.

Please let me know if you believe this display is still fixable, like it is impossible for the digits on the LCD to actually stop working? what else can i try?

Thank you so much for any help.
 

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Last edited:

kellys_eye

Jun 25, 2010
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That's a 'bog standard' 16-character 2-line LCD with built-in interface that should be readily available from many outlets. Here's a typical example.

https://www.ebay.co.uk/itm/301015639799?hash=item4615ee26f7:g:eGkAAOSwaB5XkIta

You might have to search around a bit for a module with the correct character size (your measurements don't show the actual character size themselves) but even the one I show above should be a direct replacement as far as operability is concerned. Even the dimensional drawing shown in the eBay listing is a darned good 'copy'.
 

73's de Edd

Aug 21, 2015
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SIr axrusar . . . . .


Looks like you have yourself a phone assisted / security entry system.

On my viewing of 110523 photo . . . of frontal display of operating panel . . .

I am seeing segment drop outs, as well as varying intensity of segments across all of the display.
IF you are LUCKY it will be due to "jelling" of the top and bottom side ends extremenities of a ZEBRA strip, connecting between the LCD glass panel and the associated breakout of connections of the WHITE 16 pin connector .

This condition is exacerbated if the display panel is heated by any DIRECT sunlight falling upon it, at a portion of the day.
Looks like this one has fared well, for upon ~17 years.

TESTING . . .1 2 3 TESTING !

Get the unit operating with a display, just as one of your photos shows.

Place all of two hands fingers on the back side of the panel and align each thumb at about the start and end of S and E in the SEE . . . . . or later on / next the T and Y in DIRECTORY.
That's upon the silver aluminum bezel frame just bellow that text or possibly, even touching a slight bit of the green display panel.
Put increasing pressure, on the aluminum bezel in that immediate area with a pinching action to see if the Bars in EE then pop in and are then being well visible. If so, move down to the other previously mentioned end, to see if that same added pressure action, will make TORY segments, be of of equal darkness.
If your problem corrects with pressure . . . . .we gots ourselves a Z E E E E bra strip to recondition.

If so, I will give SURGICAL procedure for doing same . . . . and the PITFALLS to avoid !

73's de Edd . . . . .


Homer Simpsons advice, after reviewing Bart's last report card . . . . wherein he had received five F’s and one D.
“Son, looks to me . . . . . like you’re spending too much time on one subject. "

.
 

axrusar

Jun 12, 2022
3
Joined
Jun 12, 2022
Messages
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UPDATE.
After some research found out the zebra strips can not purchased, and the standard 16x2 units available everywhere,

I already purchased a unit that matches exactly the measurements and placement of the pins and everything.
My unit: https://pdf1.alldatasheet.com/datasheet-pdf/view/114202/ETC1/MTC-16201X.html

Part i found:
https://www.crystalfontz.com/products/document/961/CFAH1602L-TGH-JTDatasheet.pdf

I am clueless about all this, but looking and comparing both datasheets it is pretty obvious they should be compatible.
I do have the basic skills to desolder the old 16 pin header and install in on the new board. The pins also seem to be all in the same location...
Thank you. my issue is solved i believe.
 

axrusar

Jun 12, 2022
3
Joined
Jun 12, 2022
Messages
3
SIr axrusar . . . . .

....

.

Thank you so much for your input and availability to help.
Do not worry, this is a residential entrance system and i need to make sure the fix will last and hold to the extreme Florida weather elements, so a new unit is the best way to go. I am lucky to find out these are standard displays easy to replace. Otherwise i was looking at a $4000+ new telephone entry system installation.

One little last question i have, see the resistor soldered between 2 pins in the 110621 picture... should i leave that for the new display? is that supposed to do anything?


Good luck everyone.
 

73's de Edd

Aug 21, 2015
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After some research found out the zebra strips can not purchased . . . .
You use the units existing strip(s) and merely break the surfactal glaze upon same . . .
but YOU did not respond to the affectation of the testing procedure . . .initially .

As for seeing any
REE-SISTOR ? , instead, I am only seeing a small round . . .22 pf . . . ceramic capacitor between connector pins 9 and 10.
Now if that cap was between any combination of any of the pins 1-6 that, would, be more logical.
BUT, this cap installation is being between two logic busses ? on the newly referenced units.
So that is up in the air, for any definitive answer. BUT . . .22 pf . . . . is being but a wee amount of capacitance. Expecting no adverse effect if being left in circuit.
 
Last edited:

kellys_eye

Jun 25, 2010
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One little last question i have, see the resistor soldered between 2 pins in the 110621 picture... should i leave that for the new display? is that supposed to do anything?

It's a capacitor - yes, leave it in place.
 
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