Guest richardmlea Posted December 3, 2011 Report Share Posted December 3, 2011 (edited) Hi all, Use this information at your own risk. Please take care when doing this fix as you will be heating your touch-screen up. Any damaged caused by attempting this fix is not my fault. I am posting this info as it has cured my touch-screen fault and will be of use to others but USE AT YOUR OWN RISK. Back covered onto the task at hand. This is a fix for the touch-screen of the Advent Vega and other P10AN01 devices with the same Mildex touch-screen. The fault in question is caused by the internal heat of the main board (or an external heat source such as a lamp) heating up the touch-screen. It then cools down when not in use. As the touch-screen heats and cools it expands and shrinks very slightly. Because the touch-screen is made up of laminations of glass and plastic (and the metal/conductive contacts) they expand and shrink at different rates. Eventually the laminations and the conductive contacts come apart (very slightly) and loose connection. Sometimes the problem will manifests when its gets hot sometimes when it cools down, its completely random and depend on the individual touch-screen as to when it happens (hot or cold) but the problems are the same thing. We will be heating up the touch-screen hotter than it would normally ever get and then pressing the contacts back together thus making the touch-screen work again. The Fix could also be used to fix other touch-screens with the same fault but testing may be required and melted touch-screens are your fault not mine. So we are going to heat around the edge of the touch-screen (the inside 3cm of the black bit) with a heat gun or hot hair dryer. You don’t need to heat it too much, you are looking to get it just hot enough that you can still touch it but its very warm. The chances of melting the touch-screen are very slim but be carful. For test I took a smashed touch-screen and held a cigarette lighter under is the see how long it would take to damage it. It took about 15 to 20 seconds of holding the touch-screen in the hottest part of the flame before the plastic interior laminations started to bubble and melt. Bottom line, the heat we are trying to give it will not damage the touch-screen. I used a High power heat gun, the sort of thing used to strip paint. This is much hotter than a hair dryer but because it is hotter it gets the heat into the screen quickly without heating the internal components of the Vega (LCD ect). It’s probably a good idea to turn off your Vega while you are doing this. Keep it about 3-4 inches away from the Vega and keep the heat gun moving. Don’t stop in one place and don’t hold it to close. It only to me 15- 20 seconds with the heat gun to get it hot enough but a hair dryer would take longer. As your heating it with the gun in one hand, use the other hand to test the temperature of the touch-screen. You are trying to get it hot, but not too hot to hold your hand on. When you have the touch-screen good and hot you need to use a cloth and your finger to rub/press the front of the touch. You are trying to press the contacts back onto the conductive screen. Work you way around the edge of the touch-screen paying particular attention to the bottom right corner where the ribbon connects. After rubbing around the edge you need to lay the Vega on a flat surface (a glass coffee table is perfect), put some weight on it and let it cool down. I used a wooden box and a pot plant for weight and left it for about 10 minutes. Now, the moment of truth, fingers crossed. Turn on your Vega and your touch screen should be working again. Mine works perfectly, 12 hours and counting so far. Here is a video demo of how I did it. It’s filmed on my mobile so I only had one hand free but it illustrates how to do it and shows the back of the touch-screen so you can get an idea of how the touch-screen is constructed and better understand what your trying to do. video coming soon Thanks to Vinnie1 for your input. Let me know if this works for you and give thanks if you find this post useful. Good luck to all. Edited December 3, 2011 by richardmlea Link to comment Share on other sites More sharing options...
Guest Graham Macleod Posted December 3, 2011 Report Share Posted December 3, 2011 I like the way you think! This is a great idea and I can report some - though not complete - success. I used a steam iron, turned way down. It allowed me to make the screen hot to the touch, but not so hot that I couldn't press it down. The improvement is noticeable, the Vega is usable again but strangely, only if held in a certain way. In this case only if firm pressure is applied to the back of the case, where the battery sits. If this is held firmly with the left hand, the touchscreen is just about perfect. If I loosen the pressure, it stops responding. I can't quite figure out why - a loose connection perhaps, or a faulty earthing? Thanks for the tip anyway. Link to comment Share on other sites More sharing options...
Guest richardmlea Posted December 3, 2011 Report Share Posted December 3, 2011 (edited) Hi graham, After about 24 hours mine has gone dead in the bottom left corner where the home and back buttons are on honeycomb its not completly dead but instead of pressing home it selects shift (if the keboard is on. I am now thinking pressing from the inside will be the answer as this will get more presure onto the touchscreen and pressing it from the outside is not really putting any presure on the ribbon connector. i think the ribbon connection is the main problem, its litterally mm's away from the main board so if the ribbon is getting hot the connection bettween the ribbon and the touchscreen may be coming away. The trouble is that the LCD has a PCB attached that is covering the connector so to get at it the lCD will need to come out. Not too much problem for me and you graham, as we have had the LCD out before but a little extreme from most people. Some more testing is required I think. I will post my findings soon. Take it easy, Richard Edited December 3, 2011 by richardmlea Link to comment Share on other sites More sharing options...
Guest Graham Macleod Posted December 3, 2011 Report Share Posted December 3, 2011 Actually I tried it from the inside first, removing everything and putting the heat on the glass, then pressing down on a thick paperback book. That didn't seem to work at all, made no difference. So then I did it your way and there was some improvement. I'm baffled by why it needs to be held in a certain way. This has happened before, it always seems to be fussy about where exactly it is held. On a related note, do you have any idea what - exactly - the calibration programs actually do? I've seen calibration programs before but they always ask you to touch points on the screen. One that insists that you don't touch the screen is really new to me. What could it be doing? How does it get it's calibration data? The only thing I can think of is that it's scanning and compensating for noise. Link to comment Share on other sites More sharing options...
Guest richardmlea Posted December 3, 2011 Report Share Posted December 3, 2011 On a related note, do you have any idea what - exactly - the calibration programs actually do? Sorry no. I suspect it may have something to do with magic and fairys but i cant be sure. :rolleyes: Link to comment Share on other sites More sharing options...
Guest richardmlea Posted December 3, 2011 Report Share Posted December 3, 2011 (edited) seriously, if i was to make an educated guess.... The touchscreen works by measuring the capacativity of diferent sectors of the screen (the glass has transparent a condutive coating of indium tin oxide). As you touch the screen the electrical charge in you finger changes the screens electromagnitic feild, the changes are picked up by the many sensors around the edge of the screen and the device uses these readings the know if and where you are touching the screen. So the calibration tool will zero these sensors, like pressing tare on a electric scale but for each individual sensor. Edited December 3, 2011 by richardmlea Link to comment Share on other sites More sharing options...
Guest richardmlea Posted December 3, 2011 Report Share Posted December 3, 2011 Hmm, maybe i am being a electronic hypochondriac but i think we may be getting Parasitic capacitive coupling. Link to comment Share on other sites More sharing options...
Guest Graham Macleod Posted December 4, 2011 Report Share Posted December 4, 2011 Electronic Hypochondriac? Could be those Dutch herbs :-) Let me run today's theory past you. It doesn't seem completely correct, but bear with me. The idea is that the problem is caused by removing and replacing the LCD. This involves separating it from the touchpanel by breaking the glue strips on the side. They break messily, leaving some on the lcd and most of the remainder on the touchpanel. Replacing the LCD is easy, but there's no good way of replacing the glue strips, so we just slap it on top of the damaged ones and hope for the best. This means that the new panel isn't glued in properly and moves a little - this matters because tiny changes in the gap between screen and touchpanel will throw out the calibration - calibration which is a very sensitive and tricky business reading and compensating for the electrical noise caused by the lcd panel. The second part of the theory is a bit more controversial. It's that that the three provided methods for calibration in Vegacomb don't actually work. The first is the calibration on startup. I propose that, on my machine at least, this doesn't do anything. This can be demonstrated by using multitouch visualiser, showing no difference before and after a reboot. Then there's the Shuttle tools app, which 'completes' so quickly that it's hard to believe its doing anything, and again it doesn't seem to make any difference. Finally there's the Module AP utility which complains that it's the wrong digitiser, seems to work anyway and also, makes no difference. So the result of this theory is to suggest dismantling the vega and gluing the lcd firmly down onto a pillar of superglue. Then flashing stock and using Module AP to calibrate the screen. Then and only then restoring Vegacomb. Having got this far, I think I'll try HoneyIce anyway. I'll let you know how I get on. Today is FIX THE SO**ING VEGA day. Nothing but perfection will do! Graham Link to comment Share on other sites More sharing options...
Guest richardmlea Posted December 4, 2011 Report Share Posted December 4, 2011 Hi graham, I will give a full eplaination later DONT put Cyanoacrylate (superglue) anywhere near your LCD or touchscreen. You will destroy it. Link to comment Share on other sites More sharing options...
Guest Vinnie1 Posted December 5, 2011 Report Share Posted December 5, 2011 Hiya Richard, Like a dragon would say, 'I'm out!'. Decided to send my Vega back to Currys today, as I was just about stil in the 3 month warranty, and my problem was not due to me opening it. I believe it was there from day one, and as it was a refurb, it may have been sent back in the first place cos of the screen and never repaired. As I have the chance, thought it was better to get the money back, and wait till the sales to try and get a new one for hopefully not too much more than I paid for the refurb (£139). Although, the heating up of the screen did improve it, it always seemed temporary, and then when I tryed multi touch it went nuts still. However it was perfect if the screen was flexed so as the middle was pushed 'up' ever so slightly, but then I wasn't able to touch the screen!! Good luck with your fixes, and hope you get a solid screen soon! Link to comment Share on other sites More sharing options...
Guest Graham Macleod Posted December 5, 2011 Report Share Posted December 5, 2011 Hi graham, I will give a full eplaination later DONT put Cyanoacrylate (superglue) anywhere near your LCD or touchscreen. You will destroy it. Ooops! Oh well. It seems to be working fine. Further disassembly could be a problem, but as you can tell, I'm not planning to put much more work into it. It is working quite nicely now though. I think the most important factors were firmly taping down the ribbon cable where it meets the motherboard, and placing some bubble wrap between the rear case and the battery. It's not exactly scientific :-) Link to comment Share on other sites More sharing options...
Guest richardmlea Posted December 21, 2011 Report Share Posted December 21, 2011 Well I have snapped the end of the ribbon off my touch-screen while messing about with the touch-screen while it was outside of the case. I tried to save time by doing the repair with the touch-screen outside the case but still connected to the motherboard so I could repeat the heat treatment over and over until it was completely successful. I should have been more careful or just disconnected it in-between heating’s but I didn’t and its knackered. I have tried to transplant another ribbon off another broken screen but this didn’t work (I didn’t think it would work but without any other option I had to try it). I am now stuck to using it on the dock until I can get another touch-screen (when I have more money in the new year) Overall the repair (before I tore off the end of the ribbon) was reasonably successful. The touch-screen went from completely random and unusable to 98% perfect. The only bit I didn’t get working was a half inch high by inch wide section in the bottom left corner where the home button and back buttons are in honeycomb. If used the right way around the back/home buttons and shift key on the keyboard didn’t work. If I used it upside down this solved the problem by moving it to another location. I could have used it like this but think I could have fixed it. Que Sera Sera :) Link to comment Share on other sites More sharing options...
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