Toshiba 55C350 How to Remove LCD?

[howardc64]

Backlight is out. Looks like LCD is double sided foam tape glued to the chassis. Have to cut foam tape with knife/blade?



Apple iMac >= 2012 use foam tape to glue down screen. But impossible to get LCD installed with new foam tape on with same adhesion. Many people have screen fall off and crack afterwards.

Looks like need to get 3M VHB tape to resecure it properly per post #6 here

https://www.badcaps.net/forum/showth...83#post1140983

[howardc64]

Re: Toshiba 55C350 How to Remove LCD?

UPDATE

Cut the foam, changed the backlight. Now need to get foam tape to secure LCD. 2 tricky spots on disassembly.

• The plastic diffuser and white reflector sheet is also double sided glued on the bottom approx 2x 8-10cm sections. Quite a mess, Basically will ripped the bottom edge of the reflector sheet cutting these sections with razor blade.
  
• Reflector sheet is also double sided taped down to the tub. Best to pull the tape up with the reflector sheet as tub is more sturdy.

[howardc64]

Re: Toshiba 55C350 How to Remove LCD?

Looking for double sided tape to glue the LCD back onto the frame. My understanding is 3M VHB is best but 1/4" (6mm+) width is smallest 3M makes.

Original double sided foam tape (cut to remove LCD to change backlight) is 4mm wide, ~1mm thick.

Consulted with 3M chat support, they say its common for some distributor cut/slit/convert the tape into smaller widths. But need to be done in controlled environment / tools to not contaminate and lose stickiness.

4mm wide 3M VHB tape available on aliexpress but of course suspect authenticity.

What does everyone use to reglue bezelless LCD TVs?

[EazyBone]

Re: Toshiba 55C350 How to Remove LCD?

I used b7000. I was in same boat of wondering what's a proper solution. I wouldn't want to scrape old sticky tape off screen, so I use b7000 and some very light clamping/weight. No issue doing so yet.

I have the tape also, but feel like it'd be too hard to do. Only done a couple though.

[howardc64]

Re: Toshiba 55C350 How to Remove LCD?

I used b7000. I was in same boat of wondering what's a proper solution. I wouldn't want to scrape old sticky tape off screen, so I use b7000 and some very light clamping/weight. No issue doing so yet.

I have the tape also, but feel like it'd be too hard to do. Only done a couple though.

Thanks. Chatted with AliExpress vendor (I think same/similar seller on ebay shipping from China) selling 3 meter x 4mm VHB 5952 tape. They said they are authorized distributor and cut when order is placed. Reviews seems to be good so I'll see about giving this a try... IF I can get the old tape off the LCD haha...

Will report back after success OR failure haha.

[howardc64]

Re: Toshiba 55C350 How to Remove LCD?

UPDATE

Almost successful in repair. Unfortunately cracked the LCD nearly the last step trying to remove debris from underside of the LCD.

Debris on underside of LCD Glass

To remove the double sided tape from the underside of LCD require exposing the underside to open air for extended period of time. Only way to see and clean all dust/debris particles is with LCD installed (but not double sided sticked down) and backlight on. The natural instinct is to tilt up the LCD while installed and use masking tape to remove the debris. Got every debris except the last one towards the center lower of the screen which unfortunately require higher tilt and stress on the LCD glass lifting it from one corner (one person). Thus cracked. If doing this again, definitely need 2 people so one can tilt the screen supporting from both top corners while the other person remove debris with masking tape. Alternatively go slower, mark the debris location, remove the LCD, remove debris, install, repeat.

4mm VHB 5952 Tape from AliExpress Works

Mounted the LCD onto double sided tape despite cracking LCD to test out the tape. Definitely sticks well. Likely genuine VHB tape custom cut to 4mm as noted by the seller. $7 for 3 meters.

https://www.aliexpress.us/item/22518...yAdapt=glo2usa

Nitrile Gloves

Wear these to avoid getting smudge to underside of LCD when cleaning off old tape and handling it to glue it back onto the TV chassis

Cutting Old LCD Tape

Didn't have rotating cutting wheel which would have worked better. Blade will leave black foam debris on top of backlight diffuser AND underside of LCD and require more cleaning effort.

Cleaning old tape from LCD

Takes quite a bit of time so go slow. Place LCD glass on flat table with hard flat surface so plastic scraper have a firm surface to scrap off the tape. Removing the tape with the shiny sticky surface facing the glass intact is desirable to avoid leaving too much sticky residue on the glass requiring further cleaning.

Clean up remaining residue with little bit of ISO on a small firm q-tip

Tape will cover 2 layer? levels of glass. The ~2mm thick layer faces outwards on the TV and a much thinner layer where LCD circuits are probably lithographed on. It is likely this ultra thin layer that cracked when I lifted one corner up too high trying to get last remaining debris.

Cleaning old tape from metal chassis

The chassis tape surface is textured. Old tape will just peel off. Go slow as some areas will leave residue (near corners) Just have plastic scraper near to aid glue removal in these regions.

Installing VHB Tape

I chose to install it on the metal chassis first. In hindsight, it might have been better to install on the LCD first. 4mm tape evenly aligned with inner edge of the chassis will have 1mm+ of sticky surface outside of the LCD glass after install. So its better to install on glass first for perfect alignment.

Removing under LCD debris

As noted above. 2 people is ideal to tilt up both top corners. To get to debris lower on the screen require tiling the LCD higher which is more stress on the glass. Going slower by marking debris and repeatedly removing LCD and remove debris sticky masking tape probably best.

[EazyBone]

Re: Toshiba 55C350 How to Remove LCD?

This is why I recommended the glue. Don't need to scrape everything off the LCD, just do a cleanup a bit for loose pieces, use the b7000 and glue with some books along the edges. I've had no issues that way so far

[howardc64]

Re: Toshiba 55C350 How to Remove LCD?

This is why I recommended the glue. Don't need to scrape everything off the LCD, just do a cleanup a bit for loose pieces, use the b7000 and glue with some books along the edges. I've had no issues that way so far

Indeed, for pros, time to remove double sided tape is prohibitive.

Its key to cut foam tape without making a bunch of debris. xacto and razor blade made foam debris that dumps between diffuser and LCD glass. What is your trick? cutter wheels?