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jlangford

Repaired Navigation Touch Screen

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Last Monday my wife told me the touch screen in her '07 IS-250 didn't respond to touch. Indeed, no touches registered at all, though the screen displayed everything. Which brought me to these forums, and horror stories of $6500 new parts, $2000 rebuilt, etc. My love affair with this lemon has long ended - one defect after another, recalls for so many things, too much time in the dealership. But I digress...

If your Lexus has the same manufacturing defect as mine, and you're patient/mechanically inclined, you may be able to fix it for CHEAP. As in under $50 cheap.

The culprit for this problem was a faulty connector on the touch panel. The touch panel is a 4-wire resistive panel, taped to the LCD display. The unit is made by Toshiba. There's a four wire ribbon cable that is improperly bonded to the touch panel. Sunday had been a hot day here, and upon further mental digging, my wife recalled hitting a pothole a few days before. Shock + thermal-expansion + manufacturing defect = dead nav unit = unreasonably costly expense with normal consumer operation. In my opinion Lexus should really fix this...

So the basic procedure is to remove the nav unit from the car. There are picture on the web on how to do this. The hardest part is getting the A/C vents out of the dash - when I did it I ended up removing the outer trim first, but after getting it all out I could see that the whole thing should slide out in one piece. I have some detailed photos of the clips if anyone wants them. And if you're partway mechanically inclined you can pull the unit out and a guy on ebay offers a repair service for under $600. Your car will drive with the unit out, but you have no radio, no nav, the seat airconditioning is on max, and the cabin AC is set to wherever you last left it. And the dash is lit up with pretty much every warning.

Anyhow once the nav unit is out, the outer trim for the radio, navscreen, etc all comes unclipped and slides off as one unit. To do this, remove 8 screws, undo the clips, and just pull. It required a bit of force on the right side where the cables come out, but the clips were the same on both sides - nothing hidden here. Once this is off you will see the screen unit is held in place with 4 screws. There's also a ribbon connector and a power cable that need undone. Be careful with these delicate ribbon connectors... Once the display unit is out, there are again four screws that hold the housing together. It's easy to get apart, but pay attention to the copper clips and take some photos so you remember how it goes back together.

Unhook the 4-wire ribbon connector and you're ready to troubleshoot. Labor at this point should be under an hour if things have gone smoothly, but realistically two hours.

Here's where you need a good set of test probes for your multimeter - I found a set that worked perfectly at Radio Shack for about $20 - including lots of cool micro probes, clips, needles, etc. I couldn't have made the repair without these. Also, while there, pick up a silver CircuitWriter pen for about $11. That's what I used to repair the trace.

The resistance between pins 1 and 3, and 2 and 4 should be about 500 and 1700 ohms. The resistance between the other pairs of pins, say 1/2 or 1/4, or 3/4 should be infinite until the panel is touched. When touched the resistance between those should go to something under 2k ohms. From this info you can figure out which connector is faulty. In my case the connector failed right where the two pieces of glass are sandwiched together, and by using the needle probe, I was able to get a good resistance measurement on the touch panel by wedging the needle of the probe up into the crack where the two pieces of glass join. I found a bit of live connector. So then I took a razor blade and scratched off the coating on the ribbon connector, right up to the glass, and applied some of the CircuitWriter ink there. Note that it has to dry before it's conductive. When it does dry, the panel is repaired. Seal that back up, put it together, and everything's done.

When I did this, I actually used a razor blade to completely separate the touch panel from the display, and in so doing sliced part of the ribbon connector. You can't use the CircuitWriter pen to fix that, because it has no strength. So I had to buy a $35 tube of silver conductive epoxy, and was able to repair it. This may have been better all around, but the epoxy isn't runny like the circuit writer ink, and it might have helped get under the glass panel being runny.

When I put the unit all back together (probably about two hours, being cautious, using the right screws, not forgetting any connectors, etc). The unit fired up and worked perfectly. All the warning lights on the dash were gone, and I only needed to reset the radio stations.

Financial disaster averted! I'll post some pictures of this if anyone's interested.

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that is fantastic, yes pictures would be great...some of us are willing to try anything to save the wallet....

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Hi Jacob, your post on fixing the IS touchscreen is inspiring. I have the same issue and am about to attempt the fix. One question - why did you choose to use the circuit writer vs. just touching a hot soldering iron over the bad connection to reflow the solder on it ? Could you tell that it was adhesively bonded to the glass vs soldered I guess ?

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I suck at soldering. And I don't have any precision soldering stuff. And I was worried about heat. Trust me I was tempted! Also, when I "found" the live lead I really had to press the probe's needle in between the pieces of glass - and it only made contact in exactly one spot. So I felt like the crack in the conductor was already mostly under the glass. The circuit writer ink is pretty thin, so I hoped it would flow in and work, and it did.

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Repaired it yesterday, put it back in today, works great. Total cost was $12.95 + tax to get the circuit writer stuff. Amazing fix but probably not for the light hearted ! Turned out that my bad conductor was pin #3. Thanks a ton for blazing the trail on this one, saved a ton of money.

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U think I could send u my screen and you fix it. I'll pay you. I tried it but I couldn't seperate the glass from the screen, it started chipping on me.

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I love your DIY style. I have been driving since July with a broken navigation screen. I have called in a friend with soldering experience and will attempt the fix this weekend. Wish me luck. :)

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picture of the major culprit attached, more detailed photos available at this link

https://picasaweb.google.com/jacob.langford/LexusIS250NavscreenRepair#

post-130543-0-38548200-1308117141_thumb.

So, I have figured out that pin #1 is my problem, but I have a question on the making the actual fix. How do make sure the circut writer touches the part under the glass? I have tried and tried to wedge the probe tool and have scraped the stuff off up to the glass, but I cannot see or touch the connection under the glass. Should I just put the circut writer stuff on and hope it touches? A little advice would be appreciated.

EDIT: I looked over the pictures and noticed that you chipped the glass away to get to the wire. I have done this an was able to see the wire. BTW, Good work on the pictures. :chairshot:

I am waiting for the circuitwriter to dry now; hopefully, it works like it should. We will see...

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ITS ALIVE!!! I am soooooooo happy right now! :D

I have two problems :-(

We don't have CircuitWriter where I live and no matter how much glass I chip off, the copper gets chipped away as well :-( I tried using regular solder wire but it wont connect to the copper wire under the glass because of its cohesive force. what should I do?

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ITS ALIVE!!! I am soooooooo happy right now! :D

I have two problems :-(

We don't have CircuitWriter where I live and no matter how much glass I chip off, the copper gets chipped away as well :-( I tried using regular solder wire but it wont connect to the copper wire under the glass because of its cohesive force. what should I do?

I used a really small philips screwdriver to almost grind (not chip) the glass until i saw the copper. You only need very little exposed. Also, make sure you use a razer to see the copper wire on the paper side. You have to be sure handed. Take your time. I would order the circuitwriter if I were you. It is cheap and will help bridge the copper on the glass side.

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THANK YOU !!!

It worked :-)

I tried soldering around 5 or 6 times but it didn't work. CircuitWriter should be called MagicPen :P

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Thanks jlang for your instructions and pictures. Mine was the same #1 trace. I repaired it following your instructions and it's been working for 2 months now! One thing I did differently, was to reinforce the back of the flex cable with some epoxy. Circuit writer ink broke while I was messing with the flex cable. With a little reinforcement on the back side, the repair was solid. Thanks for your help! I didn't know how to troubleshoot the screen, and your ohm measurements were right on!

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I am having trouble even getting a reading at all from any of the connections. Where are you putting the probes? I am a total newbie with this (just bought my first multi-meter for this project). The probes don't seem to be making any contact. I've bought the mircro probes, but still no reading.

I've tested the probes on some of the circuits(I'm not sure if that is even the right word) on the board (that the screen used to be attached to) just to make sure I was using the multi-meter correctly. I am getting a reading on those circuits, just not on any of the 4 lines on the ribbon connecting at the glass.

Please help.

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YYYESSSSSS!!!!! jlangford, you are THE man! My wife's touch screen in her 2006 IS350 had been out of commission since early 2009. It was working one night, and the next morning, nothing. Lexus told me the replacement was $2,400, and I insisted that it had to be a relatively simple problem that they should be able to fix. This issue was all over the web even at that time and Lexus acted like touch screen failure was a rare occurrence. Glad I waited it out! Excellent instructions and perfect guidance on the resistance readings. I had trouble getting the initial readings for troubleshooting so I just used the circuit writer on all four traces. Grinding the glass down was hard, until I used my dremel with the flex attachment and the "dentist" bit. Thanks again! May I make some sort of donation to any of your causes jlangford?

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i created this acct. on here just to let you know your the *BLEEP* bro! i follow everything you said and it work!! thanks so much

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The touchscreen in my 2006 IS 250 stopped working. Would love to fix it without paying the $2,000+ as quoted by the dealership. Does anyone in the Washington, DC metro area (DMV) know how to fix broken navs using the jlangford method? Please help!! contact me at lola02425@gmail.com

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Jlangford,

Many thanks for posting this fix. Did exactly what you stated and the nav screen works now. Cost was $20 for the circuit writer pen. I used a high power magnifying glass to help see the joint when scraping and when applying the silver solder. Makes it much easier. Let it dry overnight, test it and viola, continuity!!!

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Jlangford,

Thank you for your post. What a lifesaver. My screen went out and I was happy to find this post. Works perfect now! The only problem I have is I accidentally scratched the screen protector when I was chipping away at the glass. I did get it off and the screen is fine. Now the only problem is my screen is super shiny and super reflective! Anyone had to replace the screen protector and if so what did you use? I know what was on there was a matte anti-glare with a slight bit of tint. Thanks again J!

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I performed this fix and now have no power above the clock. The AC/Heat doesn't work, nor does the display. Has anyone had this same issue or would you have any suggestions? I have checked all the connections numerous times and I have also checked my fuses. Any advice would be appreciated.

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I have the same problem as post 23. I tried the repair and it didn't work. I took it apart and did it all again and got good readings on the meter after the repair. I put everything back in the car and only the radio works. None of the physical buttons above the radio work now. I checked all the fuses (drivers side, passengers side and under the hood). I checked all of the connections several times. The display only shows the radio station and volume at the top, but goes blank a few seconds after an adjustment is make (like it should). Is there some kind of reset?

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Just to add to the thread... this process worked for me. Thanks very much to the original poster.

For some reason, I had trouble with releasing the tabs of the air conditioning vents in the first step. for some reason, I couldn't get a good bead on them. I ended up using a pair of screw drivers to wedge in to the top edge between where the air conditioning vent meets the rest of the console so that I could see tabs.. I was then able to get them down.

I also had trouble just removing the face plate off of the console unit by itself. I did find i had to unscrew all of the components from the frame. It turned out there were two tabs additional tabs holding the plastic face plate to the metal frame in the middle of the unit itself. I couldn't see them until I removed the bottom dvd player.

For me, I think pins 2 and 4 where busted. I had to carefully chip away at the glass over the traces until I got lucky in getting both the glass away while also leaving an exposed trace I could connect to. It took some patience, but I got there in the end. Now everything is working.

Thanks!

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