The LCD has two polarizing sheets which are 90 degrees out of phase. Inside the LCD the liquid crystal ‘twists’ the light on its path into and out of the LCD. You need a polarizing film without the reflector backing that is used on the back of the LCD.
https://www.mepits.com/tutorial/250/basic-electronics/how-lcd-tv-works Jeff Birt From: M100 <[email protected]> On Behalf Of Tom Blum Sent: Friday, August 16, 2024 8:18 AM To: [email protected] Subject: Re: [M100] Restoring LCD screen Jeff, Thanks for this. The streaks and ridges are on the front-facing glass. Is the next step to scrape/pull away the material on that glass? What will I replace it with when done? >From Ken's video, I understand how the transreflactive/polarizer sheet is >installed on the back glass. Just unclear about what happens on the >front-facing glass. Tom On Fri, Aug 16, 2024, 8:30 AM <[email protected] <mailto:[email protected]> > wrote: The screen is NOT clean. You are seeing clean streaks on a very dirty glass. Jeff Birt From: M100 <[email protected] <mailto:[email protected]> > On Behalf Of Tom Blum Sent: Thursday, August 15, 2024 7:14 PM To: [email protected] <mailto:[email protected]> Subject: Re: [M100] Restoring LCD screen Here's the photo: On Thu, Aug 15, 2024, 8:12 PM Tom Blum <[email protected] <mailto:[email protected]> > wrote: Hi Ken, I've watched your very helpful video multiple times. The attached image shows the diagonal striations on the outward-facing glass of the lcd assembly. You can feel the malformation when running a finger across the glass but there is no physical issue on the back glass panel on which the replacement reflector/polarizer will be mounted. No heat was used to lift the transreflective polarizer. It actually peeled away beautifully (the old polarizer and reflector) with minimal glue left on the back glass. Tom On Thu, Aug 15, 2024, 4:09 PM Ken St. Cyr <[email protected] <mailto:[email protected]> > wrote: Can you share a photo of the diagonal waves? Did you heat the screen while removing the transflective polarizer? FWIW, I did a polarizer replacement on an M200 screen in this video and it worked out great - https://youtu.be/eBRtDURtw00 //Ken _____ From: M100 <[email protected] <mailto:[email protected]> > on behalf of Tom Blum <[email protected] <mailto:[email protected]> > Sent: Thursday, August 15, 2024 3:48 PM To: [email protected] <mailto:[email protected]> <[email protected] <mailto:[email protected]> > Subject: [M100] Restoring LCD screen Looking for some guidance regarding repair of Model 200 LCD..... Purchased a junk M200 for parts. About 3/4 of the LCD's reflective layer is burnt. Was able to peel off the reflective layer and back polarizer. What I notice now is that the LCD glass has a few, random diagonal waves in it, as if the LCD glass was heated, became fluid and then resolidified. I was thinking of purchasing and installing a new combo polarizer/reflective sheet but am wondering if the imperfections in the glass makes restoration of the LCD a lost cause. Anyone handle this before? Tom
