Deadspot on screen

[Lil E]

PowerDigi fixed my drift problem on my TX, which is awesome. I have recently developed a deadspot on the upper center portion of the screen, a bit smaller than a dime. Palm will fix for $150. Any cheaper alternatives?

Thanks,

[alt236]

Try something simple first.
See if something is stuck between the casing and the digitizer... Dusrt, screen protector, etc...

[Church Punk]

cheaper, of course!!! buy a new digitizer... is 100 bucks cheaper, just, you need to change it yourself, which is not hard at all ;)

[dmitrygr]

HeHe since you have powerdigi ANY digitizer that fits physically will do. :-) powerdigi will calibrate it. at least it should

[Lil E]

thx. suggestions as to where to purchase?

[Gregte]

pdaparts.com or usedpdaparts.com

[Lil E]

Is it particularly difficult to replace digitizer on my Palm TX. I would prefer to do it myself, as I would become unhinged if I had to do without for a week or two. Suggestions as to where to find instructions?

I think i developed my deadspot after placing a "sweating" bottle of water on the tx. does that sound likely? I've replaced my screen protector and made sure that nothing else was obstructing - and still have dime sized deadspot on upper middle. I presume this is a hardware problem and replacing digitizer - or living with deadspot are my only options. Correct?

Thx

[phreakonaleash]

Yes.

As for instructions, see http://www.youtube.com/v/PXJSnL60DlA for the open up instructions... Then, IMHo, it is a matter of reconnecting a cable (soldering?) then closing it up again...

Also, ti seems they (pdaparts) are sold out... :( be sure to add yourself to the list so that you can get one!!! I just did for my crappy digitizer.. :eek: I'd upload pictures but I may get depressed and cut myself... :o

[Gregte]

This youtube video shoes how to take the TX apart but replacing the digitizer is additional to what the video shows.

The digitizer is affixed with an adhesive to a thin metal frame that snaps onto the LCD. You need to pry the old digitizer off with a razor blade or similar item.

But before you pry it off you must disconnect the digitizer's 4 conductor ribbon cable. To do this you gently pry up the little tabs or ears on the cable's connector. This is on the left side if you are looking at the back of the LCD with the top of the LCD at the top.

To get to the cable you must peel back some tape. This tape may be a silver/gray mesh or it may be a clear plastic tape, Be sure to insert the new digitizers cable fully before pressing the tiny tabs of the connector back down. Be very gentle with this ribbon cable connector. But before you connect the cable you put the new digitizer onto the metal frame. The new digitizer will have an adhesive already on it.

There is no soldering involved.

[phreakonaleash]

See, just a matter of reconnecting ;)

Thanks for the valuable instructions, gregte.

[Lil E]

thanks greg. i've replaced the keyboard on my laptop, so i thought i could manage it. the soldering bit - which i saw referenced elsewhere - scared me off a bit. I one digitzer as good as the next? are there even options? heard that replacements are glass, which is promoted as being better. are they less likely to scratch? i use boxwave's now, which are great but not cheap.

peace,

[Gregte]

...I one digitzer as good as the next? are there even options? heard that replacements are glass, which is promoted as being better. are they less likely to scratch? i use boxwave's now, which are great but not cheap.

peace,
You can get glass or plastic digitizers for the TX. I beleive the glass one to be of better quality (will last longer) from reading I have done, and so far from my own experience of putting on a glass one.

The top layer on either is made of plastic so scratching will be the same on either. It is only the bottom layer of the digitizer which is made of glass on the glass one and both layers are made of plastic on the other.

I use a Brando screen protector which I think is almost the same thing as a boxwave. Yes, they are not cheap up front but I think they are cheaper in actual use since they outlast the cheapies many times over. I only replace every year and a half or never, depending on how long I keep the PDA.

I hate putting on screen protectors because it is so hard to get them on lint free. In fact, I would rather replace a digitizer on the TX than install a screen protector.

[Lil E]

I'm with re lint and screen protectors. Another bonus of the better quality ones - much easier to put on. Had just put one on perfectly before my dead spot debacle - first time for everything. then i had to take it off to see if it was the source of the problem. wanted to cry.

I've read that you have to be "super careful" of lint when replacing the digitizer. Is the caution overstated?

[phreakonaleash]

For the lint, here is what you do: take a hot shower with the door closed. Bring your pilot in after the shower and then put it on in there. The humidity does help alot. You may get air bubbles when you put them on but miraculously they go away after a small bit. And no lint, dust, etc!

[Gregte]

I've read that you have to be "super careful" of lint when replacing the digitizer. Is the caution overstated?

The first digitizer I put on I had no problem at all with lint. The second (another TX) It got one speck which I was able to whisk of with a small paint brush. It was very simple.

Just don't remove the protective covering from the digitizer until you are ready to apply. I used a lighted magnifying glass to visually inspect, holding stuff at the correct lighting angle to see what I was doing. I did NOT want to have to remove the new glass digitizer once I had put in in place, due to the adhesive used. However, if you put the digitizer on and then later discover lint under it, I would suggest removing the digitizer, metal frame and all from the LCD rather than peeling loose the adhesive since their is always a risk of breaking the digitizer when peeling loose the adhesive. Taking off the metal frame, with digitizer attached, for dust removal is really not difficult at all. It just snaps onto the LCD.

[philgrin]

from my experience, i would be real careful using powerdigi to correct deadspots. i may have a unique tx but i do have a bad deadspot in the upper right quadrant; one of the solutions i tried was powerdigi, both versions 1 and the beta and although the specific upper right quadrant was fixed other things got wacko on me. for instance i would tap my apps tab and the launcher x screen would appear. other non-usual occurences happened. i'm rather fed up and am ready to either send in for a hardware fix or utilize the extended warranty i'm thankful i purchased with my tx (march 2006). it's been advance/replaced once.

[phreakonaleash]

ummm... IMHO, PowerDIGI does not fix dead spots. It fixes drift. And causes no problems. I have it since 1.0 and love it very much. Very little trouble until 2.0.0.0 which is now fixed in his latest beta :-)

[BrentDC]

I didn't have a good experience with PD 1, but 2 works great.

[dmitrygr]

powerdigi fixes the issue of digitizer being non-linear. deadspots are points where digitizer senses no contact. that cannot be fixed in software. it CAN be fixed by splitting the layers and washing and air-drying them, followed by careful reassembly, but in general a new digitizer is cheaper if you value your time.

[phreakonaleash]

powerdigi fixes the issue of digitizer being non-linear. deadspots are points where digitizer senses no contact. that cannot be fixed in software. it CAN be fixed by splitting the layers and washing and air-drying them, followed by careful reassembly, but in general a new digitizer is cheaper if you value your time.
and your warranty :D
could you please iterate on how to do this wash/air dry thing without borking it up?

[dmitrygr]

i am my own warranty :-)


carefully separate the layers, but not completely, the metallized sides need to stay together, open slowly and fill with warm water, i used a little handsoap. did not rub it but swirled the water around, then a bitof clean water to wash off the soap, and then dried by putting it in front of a fan and holding it open. then closed it carefully, and reinstalled in the device.

[philgrin]

dmitrygr, i am curious re powerdigi fixing non-linearity versus dead spots. here is my deal: in note pad i begin at the top drawing a line straight across. when it gets toward the right no line appears but immediately below, about 1/4" there is a downward arc, like a sagging stomach, then the straight line picks up. when i continue with another line under the first the same occurs. nice art but not right. what is that called? i'm not tech enough to represent the occurence here.

[dmitrygr]

not sure. try powerdigi v2 with detailed calibration. it might help. if so, then its just really ****ed up digitizer, else a hole

[philgrin]

i did try pd2 which as i indicated fixed the 'hole' in that i could draw a line straight across all the way; however i had the problem then with other taps as i indicated in my first reply. maybe you could give me some insight on that problem.

[dmitrygr]

no idea. a screenshot perhaps of the notepad screen demoing the problem?

[philgrin]

okay. not to keep you in suspense, i'll work on it tomorrow afternoon. thanks for the 'screenshot' aid.

[philgrin]

i'm ashamed to say i can't get a screen shot to paste here. don't know how. i copied the pertinent page from my 'note pad' onto paint and i'm able to right click and copy but when i come to this thread to 'paste' the 'paste' option is greyed out. i have more work to do.

[dmitrygr]

in paint select save as, select jpeg, and save somewhere. then in here you can attach it by clicking "go advanced" button

[phreakonaleash]

as for screen shots on the palm, check the freeware section here. under hacks/das is a screenshot app called screendumpDA. saves .bmp to card. then you use paint or sth similar to convert to jpeg and upload as dmitry said

[philgrin]

okay, here goes. no it doesn't. where is 'go advanced' button?

[BrentDC]

It should be above where you enter text, unless your already in advanced mode.

[philgrin]

found 'go advanced' pressed it, nada.everything still greyed out.

[BrentDC]

You can't copy/paste images in this forum. At the bottom of where you enter text there is a manage attachments button. Click on it then click browse. select the image you want, and post your reply, that easy!

[philgrin]

says file is too large. i have no idea how to change size, this is hardly worth it.

[phreakonaleash]

:rolleyes:
right next to post reply
EDIT: oops

[alt236]

open the file is mspaint and save it as a jpg image :)

[philgrin]

this will be my last post (for the present) on this problem. i have hot reset, power digied, cleaned with a business card, etc and i still have the issue. fortunately i bought a two year warranty at time of purchase and i am receiving an advance/exchange.

[davidf47]

This is my second TX. Palm "fixed" my digitizer drift and dead spots last time,but they're back. PowerDigi took care of drift, but dead is dead..I thought. It seems that my dead spots react to my finger or nail!! Does anyone have experience with this and/or ideas of what to do?

[braj]

This is my second TX. Palm "fixed" my digitizer drift and dead spots last time,but they're back. PowerDigi took care of drift, but dead is dead..I thought. It seems that my dead spots react to my finger or nail!! Does anyone have experience with this and/or ideas of what to do?

Your TX is slowly evolving into an iPhone
:eek:

My second TX developed a dead spot after a year. I'm using a Treo as my daily PDA now with the TX playing internet tablet/video player role now.

[Gregte]

This is my second TX. Palm "fixed" my digitizer drift and dead spots last time,but they're back. PowerDigi took care of drift, but dead is dead..I thought. It seems that my dead spots react to my finger or nail!! Does anyone have experience with this and/or ideas of what to do?

It sounds like your finger or nail is simply a broader contact area than the stylus thus making a greater area of the two contacting surfaces of the digitizer touch each other. This would be expected. It still spells "defective digitizer".

[davidf47]

It sounds like your finger or nail is simply a broader contact area than the stylus. This would be expected. It still spells "defective digitizer".

That's not it, Greg,that's why I mentioned my nail..I've tested that theory,I took a swab and it didn't react. I think(but far from sure) that it has to do with heat or moisture or oil.

[Gregte]

That's not it, Greg,that's why I mentioned my nail..I've tested that theory,I took a swab and it didn't react. I think(but far from sure) that it has to do with heat or moisture or oil.

The way the 'digitizer' (a misnomer in itself) works on the TX is it consists of two sheets of plastic. Both sheets have an electrically conductive surface on one side of them. These two conductive surfaces face each other.

There are little tiny plastic nubs that are on the surface of one of the sheets. These nubs are nonconductive. They keep the two sheets from touching each other.

When you press with the stylus, fingernail or anything else, the two sheets touch each other at that physical location. At this point an electrical current flows from the edge of of one sheet to the stylus' touch position to the edge of the other sheet. Since the conductive laminations on the two sheets are also resistive, a different amount of current will flow depending on how close to the edge of the sheets the stylus is.

The PDA's circuitry can decide where the stylus is physically by the amount of current flowing. To do this the PDA must measure the voltage drop (this is the same as measuring current flow in known conditions) and translate that analog voltage to a digital value. In other words, the PDA has circuitry that does the digitizing of the analog voltage. The clear membrane assembly (a.k.a. "digitizer") on top of the TX's LCD is not a digitizer as its output is analog only. Thus my reference to the misnomer.

Anyway, what happens to the TX's 'digitizer' is that over time and usage, breaks occur in the microscopically thin, clear electrical coating on the two facing surfaces. When breaks occur the electricity has to take a different path other than a direct straight line from the edge to the stylus. Since the electrically conductive surface is also resistive (exhibits a significant amount of electrical resistance from one edge or side to the other) more current will flow and a smaller voltage drop occurs the closer to the source edge that the stylus is. If there are small irregularities or breaks in this current path then it has to go around the break which makes for a longer path thus a greater resistance and voltage drop. This makes the PDA think the stylus press exists somewhere other than the actual physical place. This causes 'drift'.

If there are enough breaks in a given area then there is no electrical continuity at all and this causes a dead spot.

Moisture or oil should not be able to have any affect. Heat can have an affect because thermal changes cause expansion and contraction of the plastic membranes thus conceivably causing the discontinuities to change.

Another thing with the TX's plastic type of digitizer, as opposed to the glass backed type, Is that the little plastic nubs that separate the two sheets can get mashed down to the point of doing a poor job. This also will cause irregularities in the voltage reading the circuity gets from the digitizer membrane.

There is a so called 'glass digitizer' available for the TX as a replacement item. It uses a plastic membrane on top of a glass one instead of plastic on top of plastic. Also, I think, but am not certain, that the glass one does not use little nonconductive nubs to space the two sheets apart. I say this for two reasons. First, I can actually see the little nubs on the plastic digitizer (with a magnifier) but I cannot see them on the glass one. Also, I can see moire patterns on the glass backed digitizer which appear to be exactly what you might expect to see if a gel or oil were used as the separator. This is a common technic used with resistive touch screens.

At any rate, external conditions such as moisture, oily skin etc. should have no affect on a resistive type of touch screen such as the TX uses. Temperature can, but if it does it is because the touch screen is damaged.

There is a lot of 'Google searchable' information to be had concerning the various types of touch screen technologies. Some old Palms used surface capacitive technology. The new iPhone uses projected capacitive. There are many other types and they are all different and not directly interchangeable without a redesign of the entire system.

[davidf47]

Thanks for taking time to explain the inner working of the screen. Just one more thing.. can you explain why, when using a drawing program or notepad, I can't fill in the dead spot with my stylus,but can with my finger or nail? :rolleyes:

[Lil E]

funny. also, why does a digitizer go bad? no love?

e

[Gregte]

can you explain why, when using a drawing program or notepad, I can't fill in the dead spot with my stylus,but can with my finger or nail? :rolleyes:
Contact area and pressure are the only things that come into play with this type of touch screen. The actual object used, finger, nail, swab etc. are all going to spread the pressure you apply differently. The stylus has a very small contact area. A larger object like your finger will contact a greater area and is more likely to make an actual electrical connection between the two digitizer membranes if one or both of them has numerous discontinuities in it.

[braj]

How many people with bad digis use cases that hold SD cards in front of the screen when closed? Actually it occurs to me my digi went bad first when using a flip-cover Krussel case, it dies right where the card was. I don't think it ever was impacted by it though. I stopped using that case for a long time, then got a flip-cover that has card slots, and shortly after it got a dead spot right where the card was when closed. Again I don't believe it ever impacted the screen. Could there be something about this, it seem like it may not be just a coincidence.

[Ce]

How many people with bad digis use cases that hold SD cards in front of the screen when closed?

I never used one of these cases. I'm currently using my 6th TX and after a few days of light use it's already developing (at the moment very random) a deadspot. I hope it doesn't get worse.

[davidf47]

Contact area and pressure are the only things that come into play with this type of touch screen. The actual object used, finger, nail, swab etc. are all going to spread the pressure you apply differently. The stylus has a very small contact area. A larger object like your finger will contact a greater area and is more likely to make an actual electrical connection between the two digitizer membranes if one or both of them has numerous discontinuities in it.
Thanks,again,Greg. Conclusion, I'll get a glass digitizer when my fingers are too small to make my screen work. BTW, I saw it for $50 on Palmparts.

[Lil E]

just replaced digitizer - big sense of accomplishment for me. Deadspot in middle upper of screen has been resolved. BUT, calibration is off in the bottom left of screen (in landscape mode). I use this area a lot (datebk). I have calibrated with powerdigi, which has not helped this part of screen. could this be a problem with my installation?

Suggestions GREATLY appreciated.

e

[Gregte]

... calibration is off in the bottom left of screen (in landscape mode). I use this area a lot (datebk). ...

If the calibration is off in the same physical part of the screen regardless of whether you are in portrait or landscape then it would seem to me that the digitizer must be defective. It should have a linear resistance if it is not defective and this is why a good digitizer can be calibrated using the three target points. PowerDigi is useful when a digitizer is damaged and thus exhibits non-linear resistance characteristics.

On the other hand, if an actual physical area of the digitizer is properly calibrated in portrait mode but not in landscape then I don't have a clue how that could be. I am talking about an actual physical part of the screen which is the same place regardless of which mode you are using.

If the digitizer is truly linear then it should not matter if you did not get it installed perfectly straight. If it is not completely linear (defective) then there is no way you can install it to compensate.