Stuck Line of Pixels, Fixed with Pressure.. returns

proffitt

n00b
Joined
Sep 20, 2007
Messages
6
Hello all,

I have scoured the internet in search of answers for how I might fix my lcd, but have found nothing which sounds like my particular case, and am now turning to posting my own story in hopes someone can advise.

I'm going to risk giving too much information. 2 things occurred which may have caused the line of lcd's. I feel almost sure it is only one of these 2, but I'll mention both.
I'm using a toshiba satellite 5205-s703 laptop. I took it apart because of a fan issue, and thus disconnected.. well, most everything. I put it all back together, and everything was working fine (but there was a limited time frame to determine). Then I cleaned my screen. I used a 1:1 isopropanol:water mix.. I read quite some time ago where lcd cleaning products were composed of this, so I made it myself (used DI water for what it's worth). In rubbing the screen, at some point I noticed a flicker, sort of a line flicker I guess, in the area where I now have a row of dead/stuck pixels. But I just barely noticed this, and it went right away. Laptop seemed fine, I put it in my bag, took it home, and upon reopening, a line of red pixels.
I massaged a bit, and they went away. next day, they were back. This went on this way for a few rounds. The line runs from top to bottom. Oh, I should mention I reseated the lcd cabling once more prior to trying massage and it did not help. Only pressing at the top of the line does any good. If I apply a little bit of pressure, it just goes away (and all the pixels in that line show the correct color). Eventually, the line persisted, it would go away for a very short time, then come back. Then it changed to purple, then blue, now white, and pretty permanent. If I apply pressure, it still goes away, but only with pressure applied at the top of the screen, while pressure is applied. As soon as I take my finger off, line returns.

Nobody out there seems to have this same issue, but surely someone has. It seems to me that while there is a hardware problem of some sort, clearly it's fixable at some level (since I can "fix" it by applying pressure). At this point I'd be happy if it was a dead pixel up there and the ones below it would just work okay.. the line is kind of annoying. I tried a few of the dead pixel type fixing programs (with flashy colors), but they don't seem to do anything, and at this point the pure massage doesn't seem to help (maybe it even hurt, since the problem only got worse in the long run).

Does anyone have any ideas on this one? I would be uber-appreciative.
 
Yes, I cleaned it while the screen was on.
I've seen advice since to not do this. I've done it about 15 times before with no problem-- I only use a small amount of solvent, enough for a kimwipe to absorb so I can rub with it, not enough for it to seep into cracks or really affect anything.. i wouldn't think.

still... it seems to me there's only a dead/malfunctioning pixel or few pixels at the top of my screen, and then a slew of fully capable pixels beneath. isn't there some way of knocking the pixel at top out of the equation?

I believe there is a way!
 
I don't know one of my lcds has one stuck pixel and I can't even fix that.
 
A 1600x1200 display would have 4800 vertical electrical connects at top and bottom and 1200 horizontal electical connects at left and right..

Most likely one of the 4800 vertical connects at the top has been discociated and physical pressure reestablish the connection.. Because of the dense vertical connections as well as the top of the laptop is most subjected to flexing stress..vertical lines defects are more prone occur than horizontal ones..

why 4800.. each pixel is compose of 3 subpixels.. defect, I assume.. vertical line of the red subpixel(s) allows it to twist open 100% to allow the light through on black background... different colours might indicate more vertical connects have discociated.. the combination of the 3 fully open subpixels would give you white..

For a temporary fix would might try to apply a moderate pressure on the metal frame (removed from the external case) holding lcd panel of layers of flims, electrical connects and backlight and hopefully the slight indent of the metal frame would provide enough pressure to keep the wires connected...
 
Askanison2,
I did a bit of reading about LCD's since my original post, so I'm with you completely on the 3 subpixels and twisting crystals.
As to the suggestion, it would of course be awesome if I could come up with something a little bit more.. elegant (I'm imagining a cool trick like heating it just right or something).. but I'm not above a little rigging, if I can make it work out. So if I understand you correctly, you're suggesting I would remove the lcd (at least partially) from it's casing, and then either bend some metal on the edging, or insert some sort of object, either solution with the intent of creating some permanent pressure on this row of pixels. I'll have to check out the service manual and consider whether the risk of this procedure outweighs potential benefits.

I wonder what really happened now, whether some water snuck in and effectively shorted out a few transistors, or if there is a physically broken (from pressure) component. Knowing all of that could help with a solution, assuming there really is one.

This certainly isn't my #1 laptop anymore and hence why I'm not above trying some less elegant solutions. certainly would make me happy if I could come up with one just elegant enough not to have guests asking why I have a large clothespin attached to my laptop.

thx for ideas! I'll definitely post back if/when I come up with any solution (or you know, fry my whole lcd).
 
okay then,

my wife is out of town, so I've had a bit of free time to play and try to fix things, and I've come up with what seems to be a working solution, low-tech but certainly better than a clothespin.

I found some info somewhere in some mac forums where someone mentioned something similar with pressure fixing the situation, fixed by simply inserting some sort of a shim. This is what I did. I took my lcd assembly apart using a toshiba repair manual available here:
http://www.eserviceinfo.com/downloadsm/30616/toshiba_satellite 5205-s505.html

(for whatever reason this download is 4 parts, I think only part one will unpack for me though, and had all the info I needed). The disassembly is pretty easy, you remove the pieces of tape covering screws, remove the screws (on the sides of mine there are 3 screws each side, but only the top and bottom ones need be removed)-- also, the repair manual I was reading suggests disconnecting the inverter board, but this is not necessary. I simply rotated the lcd out, then looked for something to stick in there before I put it back together. I decided on taking electrical tape, cutting it in pretty small square pieces, and just taping it on a place on the back of the lcd where I determined a small amount of pressure fixed the situation. I kept the laptop on during this process, maybe not advisable, but easy to see whether what I was doing was successful. I may have slightly overdone the thickness of tape (I'd guess it's something like 15-20 pieces thick), because if I move the lcd now, I can see that pressure point in the screen, but when sitting still, the screen looks as beautiful as day one. Hopefully, the creation of a pressure point here doesn't greatly increase the risk of serious damage from a slight bump or something. But this one pretty much sits still, so I think it will be fine, and I'm so happy to have that line gone. If the "raindrop effect" around that pressure point gets to me at any point, I can always take it back apart and see if thinning the tape out some fixes that while still fixing the pixel line.

so there, naysayers! no dead pixels on my screen. I'm still curious as to the root cause of this, as I'm not totally understanding how the cleaning caused this. I now believe based on what I've read and seen that this was not a failure on the part of a pixel, but rather a failure to make a good connection somewhere back there. The pressure just restored this connection, I think.

well, thanks for your thoughts anyway, hopefully someone else out there finds this helpful.
 
Your problem is definitely a single bad connection or a partial short caused by the cleaning fluid.
Applying pressure and getting it to work doesnt help decide which one sadly.

Applying pressure to a bad connection might make the connection.
Applying pressure to the short circuit might force the fluid out, thereby reducing the severity of the short, allowing it to function.

Put the laptop in a warm dry place for a day.
This is likely to help if the problem is caused by fluid.
 
Your problem is definitely a single bad connection or a partial short caused by the cleaning fluid.
Applying pressure and getting it to work doesnt help decide which one sadly.

Applying pressure to a bad connection might make the connection.
Applying pressure to the short circuit might force the fluid out, thereby reducing the severity of the short, allowing it to function.

Put the laptop in a warm dry place for a day.
This is likely to help if the problem is caused by fluid.
The disconnect is most probably not caused by fluid.. if so you can leave the notebook in a depressurised chamber with activated silica gel..

The disconnection is most like to occur at the top of the laptop where is is subjected most to flexing when opening and closing the laptop .. resulting in the physical breakage of electrical contacts.
 
yea, I'm voting this one was not caused by the liquid, personally. I just don't think I use enough to actually get anywhere and do any harm. Also, following the cleaning, there was definitely a period of activity with no problem, at which point the screen was dry. It was only following taking it home that I had a new problem. My guess is the timing was somewhat coincidental with regard to cleaning. Perhaps the massive dismantling of the entire computer played a role-- while having the computer upside down screwing and unscrewing things, pulling on things to undo "catches", etc, maybe during all that I loosened something in there.

I'm pretty satisfied with my solution. If it fails or I decide to try for something more high-tech, I'll be sure to post back.
 
Back
Top