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Picture of Repair a Malfunctioning LCD
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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 1: Tools Needed

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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

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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

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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

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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.

Step 5: Results

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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.
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PlumsteadT21 days ago

Im struggling with a Casio fx85gt. If anyone can help me, Im at the ribbon stage. If you can help me please reply! Or at least guide me.

Photo on 11-03-2015 at 5.17 pm.jpgPhoto on 11-03-2015 at 5.16 pm.jpgPhoto on 11-03-2015 at 5.17 pm #2.jpg
PlumsteadT21 days ago

Im struggling with a Casio fx85gt. If anyone can help me, Im at the ribbon stage. If you can help me please reply! Or at least guide me.

Photo on 11-03-2015 at 5.17 pm.jpgPhoto on 11-03-2015 at 5.16 pm.jpgPhoto on 11-03-2015 at 5.17 pm #2.jpg
Thanks
JDurbin071 month ago
assbanger1 month ago

Excellent method !!! I recently repaired my trusty CASIO fx-911Z calculator. Tools used – hair dryer. Probably the proper (not too high) temperature is the key, not the pressure itself. My LCD started working properly some time after the heating took place. Probably the adhesive set again properly. Kudoz to you !

SparkyRadar made it!1 month ago

Thanks! I was able to repair a "Kill-A-Watt""P4480" power meter that had lost all of it's digits on the LCD display (just a few "ghost" segments). Applied heat from heat gun & rubbed down the ribbon where it attaches to the PC board with pencil eraser & the edge of wood nail file. This meter has lots of screws to remove to get the circuit boards loose but was worth the effort...a replacement is $45. or so.

Kill-A-Watt_P4480_Fixed.jpgKill-A-Watt_P4480_Ribbon.jpg
nitin.deoli2 months ago

THANKING YOU ADMIN

USING YOUR TECHNIQUE I MADE MY FLAIR FC-995 MS CALCULATOR TO WORK AGAIN AND I WILL SHARE YOUR TECHNIQUE TO MY FRIENDS ONC AGAIN THANKING YOU.

BEST WISHES

ThusharaA13 months ago

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

Your the best mate. It worked perfect
tcambrón4 months ago

Thanks maan. I was thinking of doing this on a TV. Other TV repair people only put some rubber padding thing. When putting the LCD frame back on the rubber padding will press against the tabs. Today was my first LCD repair I did so I did with what tips I know and was going to try the heat gun thing next.

okanagansage4 months ago

Thanks!! I fixed the lcd screen on my Panasonic land-line phone. The lcd was unreadable and now it is functional. The third row of text is missing a bit off the top but it's readable. The lcd is glued directly on top of a small pcb board so I used a hair dryer on the back of the board and then pressed the two together. It took multiple times and I had the hair dryer nozzle pressed right up against the back of the pcb board, moving it from spot to spot repeatedly and then pressing on either side of the board/screen. Had to put on a pair of gloves, though. It heats up quite a bit.

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robina.kerr.55 months ago

Worked perfectly. Set my Aoyue 968 to 140 degrees celsius and pushed with a plastic spudger.

djmachet5 months ago

100 quid saved on my honeywell CMS921 thermostat display. 95% display fixed but good enough to read the temperatures again!!! lets see how long this lasts - thanks a bunch

kingofrandom92 made it!7 months 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!

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brooney21 year 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.
HadassaF brooney27 months ago

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

haha

HadassaF7 months 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-kilr10 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 lepreazul11 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 Hebron11 months ago

cool good job on the i'ble

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 51 year ago
Thanks! Works great! GOD bless you
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