Instructables
This Instructable will show you how to repair a LCD that has dead rows and\or columns using a minimum of time and tools. The example shown here is a small LCD in a cordless telephone, but the same principle can be used in other devices as well.
 
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Step 2: Disassembly

Disassemble the device to expose the LCD. Obviously, this step will vary by device. If you are having trouble getting your particular device apart, try Googleing "'yourdevicename' disassembly".

Step 4: Repair the Connections

Picture of Repair the Connections
Using LOW heat (you do not want to melt the ribbon or the solder on the board), slowly heat the ribbon cable where it is connected to the mainboard to soften the glue. At the same time, gently but firmly rub the connection strip with the pencil eraser.
Tips:
1. Try to avoid directing too much hot air onto the LCD itself as this could damage it.
2. Apply enough heat to melt the glue holding the ribbon connection, but not enough to melt the cable itself.
3. If after the first try the problem is not resolved, try rubbing the connections down with something firmer. I repaired two identical phones using this method, and the second one required that I use the back of a plastic screwdriver to force down the connections.
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kingofrandom92 made it!5 days ago

It worked for me on my ti-86. had lines all across the LCD and its working (for) now :))))) glad I don't have to throw it away. thank you blakhatt!

2014-08-26 11.31.22.jpg
brooney27 months ago
I have a honeywell 921 which is also similar to a number of similar models 927 etc. I followed the instructables how to fix an LCD screen. This worked perfect.
Take the 921 apart.
You can remove the screen from the main circuit board.
Remove the LCD display from the plastic protective cover.
Gently separate the LCD display from its circuit board.
Apply a small amount of heat to the ribbon, I used the wife's hair dryer.
Gently push down all the ribbon cable connections to both circuit board and LCD display. I used the bottom of a pencil.
Let it cool down, lash it all back together then ta daaaaa! should be back to normal again.

i have the same honeywell 921 and i cant get the lcd display to work properly. numbers and letters are still missing.

haha

HadassaF10 days ago

hi i have the same honeywell cm921 and the lcs is still breaking up and missing numbers even after ive done all this. i rubbed gently on very low heat on the ribbon cable but still no luck.

hugomerlo3 years ago
Hello, I read these steps and I was skeptical about the results. Then I read all your comments and I became thruster. I am glad I tried since I was able to repair two baby LCD monitors. One was corrected 100% and the other about 95%. I had to heat the ribbon four times in order to get these results and I just rubbed as hard as in paper trying to erase a strong mark pencil writing. It is almost as good as new. Thanks for saving my Angel Care LCD Monitors!!

this info is from member TILCAVE and was a great success for me. Before you start heating and rubbing the ribbon, look at it with a magnifying glass first, and see if the the ribbon contacts are aligned or unaligned with each circuit board contact. If the are unaligned with each contact already, then ONLY rub in one direction (the direction that would fix the alignments). Rubbing back AND forth with heat wasn't working for me. Then I used a magnifying glass and saw all the contacts were misaligned in to the right. This was my ah-ha moment. So while the glue was warm, I rubbed the ribbon ONLY to the left 20 times. The alignment still looked too far right to me, but the display turned out perfect so that was good enough for me.

I signed up for instructables just to thank the OP and re-iterate what hugomerio has said - the steps worked perfectly for me Angel Care model # AC401 (AC-401) baby monitors. We returned from a recent trip and the parent monitor was virtually unreadable. I was able to restore it to ~100% functional using small phillips screwdrivers, a plastic pry tool, a sharp knife (to cut some glue), my wife's hairdryer, and an eraser. Again, OP, thank you very much for the how-to, and thanks to hugomerio for trying this, responding back, and getting the post to appear on my google search!

FYI, for the Angel Care AC401: 1) remove the batteries. 2) remove the four phillips case screws (all on the back; 2 holding the blue belt clip and two under the battery tray). 3) remove the blue belt clip. 4) carefully separate the front and back case. 5) remove two smaller phillips screws from the first control board.6) remove two more phillips screws for the second control board. 7) remove two even smaller screws from the LED display. 8) fold back the display while cutting the glue. 9) heat and erase as above. 10) put together reverse of removal (replace batteries to test screen before securing four case screws).

One more thing - it was relatively easy and took all of ~10 minutes while watching my two young girls. Would recommend even for the beginner.

simi-kilr3 months ago

It didn't work for me, I now have less digits than I started with. I started with using low heat for only a few seconds and was very gentle & increased the heat as I went on. :/ oh well.

lepreazul2 years ago
thank you! I repaired the LCD diplay of my Dymo Labelpoint 100 with a hair dryer!
oz9els lepreazul4 months ago

Tried to fix mine today, the LCD is about 10% working, but managed to get it to work 80%..I got to give it a try more one of these days to get the last 20% :-)

But a huge success - Thanks to instructables for the tips..

A little disassembly instruction for the Dymo LabelPoint 100:

1. Remove batteries - Remove two screws in battery compartment
2. Remove label-casette - Remove two screws, lift cutter, remove one screw
3. open case, remove two screws and the display is disposed.

Ryan Hebron4 months ago

cool good job on the i'ble

chromedome455 months ago

QUOTE

Step 4 Repair the Connections

Using LOW heat (you do not want to melt the ribbon or the
solder on the board), slowly heat the ribbon cable where it is connected to the
mainboard to soften the glue. At the same time, gently but firmly rub the
connection strip with the pencil eraser.

Tips:

1. Try to avoid directing too much hot air onto the LCD itself as this could
damage it.

2. Apply enough heat to melt the glue holding the ribbon connection, but not
enough to melt the cable itself.

3. If after the first try the problem is not resolved, try rubbing the
connections down with something firmer. I repaired two identical phones using
this method, and the second one required that I use the back of a plastic
screwdriver to force down the connections.

http://www.instructables.com/id/Repair-a-Malfunctioning-LCD/

UNQUOTE

The melting of the glue and the pressure on the ribbon cable with a pencil eraser head, is that to insure that the contacts of the ribbon cable to the row of electrodes in the 'motherboard' will be restored?

So, that is a matter of poor connection, otherwise everything is in order?

No need to replace any parts?

Good, that I did not dislodge the cable ribbon from the motherboard, on the mistaken idea that I had to remove it in order to rub with the pencil eraser head on the board electrodes?

Please comment on my thinking.

Marius de Jess

pretty cool. will this approach work on say a microwave LCD or maybe an alarm clock?
yes, but since those are line powered, be extremely careful of capacitors in particular. I wouldn't mess with the microwave because there is a huge cap in there, and you could damage the magnetron/ shielding to the point where it could leak microwaves and give you cataracts and fry all unshielded electronics in the area.
maestro8 is quite correct with his reply. The sheilding within a microwave isnt as critical as the scare mongers make out. I remember talking with techs regarding microwaves when they first came out. To test, you would jam the door switch and put your hand in on low power to feel if there was any 'warming'. Obviously they werent as high in power as they are now but it was a quick test that was common practice among original m'wave techs.

Pleas do not take such risks.In earlier days nobody knew the damages that could be caused. Marie Curie did not know about radiations and died of cancer. likewise earlier the techies were not aware of the dangers. Now that we know do not put your hands. Just switch on your mobile near a working oven and the screen will show disturbance if it is working.

meh. but some people take things apart with drills and hacksaws. about the cap, some go up to .9uf, storing around 1.8 joules at 2kv. while most likely not lethal, it wouldn't be pleasant.
Lol. homebrew EMP from a microwave....hmm
been there, done that, got arrested =P
maestro8 ramses5 years ago
To what "huge cap" are you referring? Most microwaves have a small (100s of pf) capacitor in the HV stage, but it is often coupled with a parallel resistor that would drain any charge on the cap quite quickly. Even without the resistor, the cap would drain itself in a small fraction of a second, through the resistance of the circuit in which it is connected. Also, the magnetron and shielding isn't as fragile as you're implying. It would take a hacksaw or drill to do the type of damage that would cause microwaves to leak. Even then, the leaked microwaves lose power as they dissipate into the room (remember the inverse-square law?) It would take quite a large leak to damage anything in the vicinity.
Actually, it would only take a very small hole, the size of 1/2 wavelength or a multiple thereof to radiate and cause EMI. Hence the term, micro-wave.
for a fun read, check out Waveguides.
Depending on the alarm clock...those ones with the red lines that make up the numbers are actually surface mount LEDs, made to look like an LCD.
ico 510 months ago
Thanks! Works great! GOD bless you
hello
I have lot of operator panel used in ATM machine , only of this reason i have scrap almost 40. can i try this method on this.
RMH11 year ago
Hi: I tried this trick on my WW calculator, and it worked almost perfectly. A little bit of the print still didn't show so I tried it again. Unfortunately, I sliced the ribbon cable in two. Any suggestions where I might get a new ribbon cable? BTW, your trick is awesome; it was a user error, fer sure!! I am guessing that I can remove the old ribbon, yes? FYI--the ribbon is 2" long.
jujavie1 year ago
You are a genius. I've repaired my DECT display using a hair dryer. I scared because the screen went almost to black. It appeared a big black spot on the screen but it began to disappear as soon as the screen was cooling down. Later the screen was perfect. Thank you.
wingerr1 year ago
Is there any reference describing the nature of the signals on the ribbon cable and interface at the LCD display? I've got an Ambient 5 day weather forecaster with missing symbols on the display, likely due to open connections on the ribbon. I'll give it a try with a hot glue gun for heating up the connections, but there may be some open traces in the ribbon itself from what I could see. Is the adhesive actually in between the conductive paths on the full length of the ribbon or was it applied only at the connection surface. Wondering if i can cut away the bad section and use a fresh section.
Thanks for the great advice!!! I used your tip to repair the lcd screen on my Honeywell CM921 wireless thermostat, saving me £80 - £100!!
I don't have a hot air gun, I used a glue gun instead. I wrapped the glue gun tip with aluminum foil to prevent the glue from flowing out. Then run the glue gun back and forth over the ribbon. It is because I cannot control the temperature of the glue gun, I used the speed of running the glue gun to control the temperature. I started with a faster action and see if the ribbon is "glued" onto the PCB board. If not, then slowed the speed until I found a good speed where the ribbon started to stay on the PCB board. It worked. Thanks for the idea from blakhatt.
I have just succeeded with the hot glue gun and tin foil. This method was really good for a complete re-application of the LCD plastic ribbon.

My LCD ribbon was very worn and open circuit so i removed the ribbon carefully from the PCB end and trimmed it back using a scalpel and ruler so i had a clean ribbon. You must make sure you have enough ribbon length to do this. Also clean off any old LCD ribbon debris from PCB pads.

Then to re-apply use the hot glue gun and tinfoil method but only tack down one end first of the ribbon to the PCB to get good alignment. You can check alignment with magnify glass. Then tack down the rest.

marlarius2 years ago
I have 3 Philips cordless phones that all have broken displays in various degrees. Using your instructions I fixed them all within half an hour!

I used the hotair tip for my Portasol gas soldering iron as the heater. It is perfect for the purpose.

I captured the steps in these 4 images.







1.jpg2.jpg3.jpg4.jpg
Tilcave2 years ago
Before you start heating and rubbing the ribbon, look at it with a magnifying glass first, and see if the the ribbon contacts are aligned or unaligned with each circuit board contact. If the are unaligned with each contact already, then ONLY rub in one direction (the direction that would fix the alignments). Rubbing back AND forth with heat wasn't working for me. Then I used a magnifying glass and saw all the contacts were misaligned in to the right. This was my ah-ha moment. So while the glue was warm, I rubbed the ribbon ONLY to the left 20 times. The alignment still looked too far right to me, but the display turned out perfect so that was good enough for me.
airsnake572 years ago
There is an old TI calculator model I really like to keep in my pocket. I have gone through a few that ended up with bad displays. I followed this link and TA DA! I was able to fix 3 out of 3!!!! I am very impressed. Thanks!
It worked on my TI-86 graphing calculator, but I do not know if I would ever do that again. What a pain to gain access to the connections on the lcd.......

If you are interested in complete professional information on how to repair LCD televisions, please be sure to check out this link: http://unique.octopis.com/LCD_Repair.htm
JellyWoo5 years ago
Will this work with something with a bigger screen? (http://www.franklin.com/estore/dictionary/SCD-1870/)
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