Introduction: Repair a Malfunctioning LCD

Picture of Repair a Malfunctioning LCD

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.

Step 1: Tools Needed

Picture of Tools Needed

This fix can be performed using a minimum of tools. You need only the tools necessary to disassemble the device (in this case only one screwdriver was necessary), a hot-air gun (a powerful hair dryer may work), and a pencil eraser.

Step 2: Disassembly

Picture of 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 3: Prep the Screen

Picture of Prep the Screen

Prepare the screen for repair by exposing the ribbon cable on the backside of the screen. In this phone, there is a plastic clip holding the LCD that must be temporarily removed. A plastic-coated paper clip is a handy for holding the LCD down while you work.

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.
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.

Step 5: Results

Picture of Results

With any luck, your results will be something like this. This repair, including disassembly, took approximately ten minutes to complete and the results are excellent; the screen is 100% functional again.


xoundbox (author)2017-09-15

Fixed my old calculator! Just wanted to say thank you!

IrishSnow35 (author)2016-06-10

This made me squeal when it worked! I fixed an old treadmill computer from a machine I bought second-hand. There was a broken connection on the breadboard so I dunno if that work but we'll see! I didn't have a heat gun, blow dryer or clothes iron to use, but I made it work with the end of my hot glue gun. Thanks, God bless!

kyuholee (author)IrishSnow352017-08-04

Thank you, glue gun worked like a charm!

Alden Tortem (author)2017-02-17

Actually we can repair even batteries using very simple method. Thank you KrzysztofC12 ! :)

KrzysztofC12 made it! (author)2017-02-09

Hot air is dangerous - I recommend using it on screwdrivers tip and then use warm tip to do the job instead of direct hot air

earn101 (author)2015-04-27

Just repaired my Honeywell CMS921 thermostat display, fully working save £75+ Thanks!

andy364 (author)earn1012015-09-04

No ribbon strip on my CMS921 just 8 pins that plug into the PCB. Please advise!! :-)

JamesI6 (author)andy3642015-11-02

I just got my CM921 to work - so, carefully unplug or remove the lcd unit from the circuit board (8 pins i think) then separate the white board (same size as the lcd) from the back of the lcd display (it was glued on one side and i used a scalpel) the lcd will then flip over and you can see the ribbon, then follow the instructions above, return the lcd back down on top of the little white board as before and plug it back in...

MattM353 (author)JamesI62017-02-08

Thanks for your post. You just saved me a £25 repair cost and a 1 week wait! Easy-peasey, broken to working in 10 minutes.

ET60 (author)andy3642015-11-29

There may be a thin conductive rubber strip between the glass of the display & the board it is attached to. Over time this rubber can leak an insulating compound onto the interface connection that can, at times, be removed by removing the strip and gently rubbing it with a clean soft eraser. Be gentle as it can be fragile & easily damaged. This was an effective repair in the early days of these displays.

rorro33 (author)2017-02-07

I did it ! and My old house phone is working again!Thank you so much!!!!

Salils (author)2015-04-27

Has anyone done this with a TI-83+ graphing calculator or similar? I'm not sure which cable/part of the cable is likely not making contact? I'm missing a row of pixels. Any thoughts?

JeanU2 (author)Salils2016-09-26

Fix the cable just below J6, J4, & CON2 (you should be able to lift the LCD screen up off the board & pull the ribbon semi-straight to see the connections). There is a YouTube video with exact instructions for the TI-83+.

Salils (author)Salils2015-04-27

ps: I've tried a couple places but I'm not sure where is most likely and I'm afraid to be too aggressive with the heat gun until I'm certain.

IdaJ2 made it! (author)2016-09-03

When I found my old calculator that had not been used the last 13 years and noticed that a battery change was not helping I thought its time was over. The screen did not want to display the whole numbers, only part of them was working. But I googled the problem and found this guide and decided to give it a try. I opened it up and found the striped cable leading to the screen. Took a hairdryer and warmed the edges up. Pressed with the backside of a pencil and repeated a couple of times and to my surprise I got it working again! Great success! Thanks alot for the guide! Without it the calculator would be in the trash allready. A shame, when it turned out to be such an "easy" fix! All the best, greetings from Sweden!

Painter VerLan (author)2016-04-19

Anyone tried to repair Sharp Oxford dictionary PW E550? The ribbon cable is held down by a piece of tape. Before I run out to buy a hot air gun would it work on tape?

KristyS20 (author)Painter VerLan2016-08-12

I just repaired a calculator that had the connectors held down by tape. I used a hairdryer on high heat and it did not mess up the tape.

KristyS20 (author)2016-08-12

Thank you!!! This totally worked. I just repaired my TI-36X Solar Calculator that had 2 semi-burnt out cells.

I used a hair dryer on the highest setting and the handle of a plastic makeup brush to rub the connectors as I heated them up. It did take about 5 minutes or so to get the right amount of heat and to find the exact contacts that were broken.

loulos1 (author)2016-06-05

Thank you it work nicely

steeri1974 made it! (author)2016-05-26

Thank you for a very good and useful instruction!! I could because of you repair a DYMO 1000 Plus. I was just days away from discarding it, but now it got a new life :-) Google and Instructables is powerful.

radiumfu (author)2015-04-11

Very helpful, I fixed my kill a watts P4480, will try fix my 2001 Audi A4 dashboard center LCD display panel.

joknrok (author)radiumfu2015-12-15

Hey there, I'm dealing with the Audi a4 LCD issue as well, tho I haven't found any mention online of success with anything other than replacing the whole LCD panel (requiring tricky soldering & pricey screen)... Any success with this method? Or anyone out there have alternative solutions that've worked? (Ref to 2001 Audi a4 b5 inst cluster LCD multi info display =MID)
Thank in advance!

radiumfu (author)joknrok2016-05-23

I tried few times, never get complete fix, just getting better, but once getting into summer, my work gone, give up

waraji (author)radiumfu2016-05-22

Does your Kill A Watt P4480 still work after fix?
This fix makes sense because my Kill A Watt P4460 (different model) display stopped partially working after I left it in the sun for a while.

radiumfu (author)waraji2016-05-23

Yes, work for a while, then the display turn out again, I feel this model has design problem, I own 3, one of it has this issue, I have done this fix few times. No fun

NicoleE30 (author)2016-04-07

I dont have a hot air gun... Can I use a blow dryer?

YassinZ1 made it! (author)2016-04-02

"Yes it Works ?! Now i have alot of appliances to fix and money to save ;-) ."

fCauneau (author)2016-03-23

Yes it works ! Thanks a lot for these instructions !

orlins92 (author)2016-02-06
I love You ! I had broken my harmony remote one, the screen touch , I was sad. With your method , it works perfectly !!! thanks thanks thanks !!!
seriouscyrus (author)2016-02-04

Thanks! I didn't have a hot air gun, or hair dryer, but I managed to make it work with a clothes iron.

bendykoh (author)2016-01-30

I found similar methods over the net, but I especially love the tip on using something harder to press on the ribbon. It worked! Thanks!

JarrettP3 (author)2016-01-20

Don't know what to do because I can get the screen to work for a few seconds but then it just goes away.

sgiane (author)2016-01-14

Great tutorial.

I tried as described but no success, however when I either stretch the ribbon OR bend the end of the ribbon attached to the glass (almost 180 degrees), then the display DOES WORK perfectly. When I try to reassemble the clock, the display fails again.

Can I do the same process on the glass end of the ribbon? (I guess I should not open the glass display to check the ribbon contacts... )

Thanks for any other help.

blueymac (author)2016-01-05

I have a LCD screen off a vdo dayton ms 4200 gps car radio that goes darker as the unit warms up,the unit works fine otherwise,does anyone have any idea how to fix this

kaveh2 (author)2015-12-22

Thank you man.

i was searching for something like this to repair my calculator.

JohnL177 (author)2015-11-16

Thanks for this! I repaired my little HP 6S with a hair dryer and the pencil eraser. Took two times and I really cooked it, but after it cooled down all the segments of the number screen worked.

DIY-Stu (author)2015-09-20

This is great! It took me a while to fix the display on my sharp calculator, heating with a hair dryer and pressing with a pencil eraser. In the end I tried pushing harder, and it worked. BTW, if your display goes NEGATIVE, you have to flip the polarized plastic display over.

Can this fix be applied to an android phone?

Juan A.F made it! (author)2015-10-29

I repaired my dymo pocket. Now works like a charm. Thanks.

mabelrxu made it! (author)2015-09-12

Just fixed my Faberware Kitchen Timer ... becareful when using a heat gun, I accidentally melted my cable ribbon just a little, lol.

JRR3 (author)2015-08-20

Worked for me! I used my company's industrial heat gun, so I had to sweep it left and right stopping and starting about seven times - in order to prevent one area from overheating. Between starts and stops, I used a pen cap to press down on the ribbon cable, where it connected to the circuit board.

ThusharaA1 (author)2014-12-24

I made it.I fixed my Nissan Quest LCD display for fuel and tempreture .Thanks for your vedio.

VictorT4 (author)ThusharaA12015-08-05

Hey buddy I need to fix my Quest's lcd. Did you use a heat gun or hair dryer?

ebasir (author)2015-07-29

Thank you very much. It took me about 30 minutes due to a more complex at&t ML17929. I'm still mising 2 top lines, but it was much better than the BLANK display I had previously. Maybe with some more heating and rubbing, it would be 100%. I used a hair dryer on the low heat setting.

anjibern (author)2015-07-11

I fixed my daughters little bookmark dictionary that wasn't displaying anything. Worked like a charm. Thank you so so much!

kontrol (author)2015-06-12

I have an atomic clock / indoor thermometer with a large display. There are pads on the little circuit board, but no ribbon cable. Can anyone explain to me how these work? Any repair tips? I really do not understand how the information gets from the pads to the panel.

mario59 (author)2009-06-23

I WOULD LOVE if it works... I have a Sharp multifunction graphical calculator that has THE VERY SAME display ribbon connector and LCD.... I REALLY, REALLY, REALLY, REALLY, REALLY, REALLY, REALLY, REALLY, REALLY, REALLY, REALLY, hope this will work also for me!! I was in eager to find a suitable solution on the net and maybe you did my day! This evening I'll RUSH home and try it! Thanks friend! ciao Mario

arduinoe (author)mario592009-06-23

calculators arent that expensive , lol

Mine is, and mine is cheaper than some others that I've seen and want. TI 84+SE w00t, my calc rocks!

Beats mine. I got a TI-83+. I want an nSpire.

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