PowerBook 150 - screens all destroyed?!

[techgeek]

From the LCD replacement hunt thread:

I'm wondering if plasticizer leaching within the close confines of a closed PowerBook over many years may be the culprit? If they're worried about the effects of leaching on drugs and foods for human consumption stored in containers within their expiration dates, multiple years of it concerns me. Dunno, but it seems to me it wouldn't take much to eat away at thin film plastics and adhesives? The variety of storage situations across environments and continents has made this my primary suspect.

As a chemist, hat do you make of that notion, techgeek?

I would rather attribute it to the adhesive's aging. I thought about leaching, humidity and what not, but these can't explain most of my observations. In theory, it should have been the humidity, since the polarizers are usually made of polyvinyl alcohol, which is known to absorb water (because it has -OH groups sticking out of the practically linear polymer chains). But in our home the humidity is reduced to a minimum, so this can't explain it. The leaching is caused by the addition of phthalates, but I see no reason for adding phthalates to PVA films  (they are usually added to PVC), since they are highly flexible on their own. Also the leaching doesn't require that long to occur (5-10 years will be more than enough). Also, the way the laptops are stored shouldn't matter much - I kept my PB 520c screen open on a shelf, because of the infamous hinge fragility. All others were stored in drawers. The other mystery is why none of my PC laptops are affected (yet)?!? My Lombard shows damage which appears to be under the glass, but this could be the second polarizer - It don't know. I am absolutely puzzled, because none of this points to a single reason. I could be a combination of many effects.

 

[Trash80toHP_Mini]

I figured the process that turns the infamous Spindler era ABS into crumbling piles of shards and dust to be leaching of the plasticisers from bad formulations. Happens to all plastics I know of, but not at such a high rate and such spectacular failures.

The 1400c I've kept open on the AppleDisplay is probably the only PB I own that has spent more than half its lifetime with the lid open. So the film's breathing in leaching plasticisers from within a closed lid over many, many years would be the one "relative" constant  I could come up with.

Aging's a good candidate, but that seems out of whack somehow. Gathering data here for statistical analysis would be interesting. Model number and date of production of failed film books and numbers on the unaffected 'Books in those collections would be a good thing to start.

 

[techknight]

Well I do know that CRTS made in the 60s and even into the 70s that had Safety glass used a PVA bonding agent that fails and causes "Cateracts" in the front and the only fix is to heat the tube and slowly remove the safety glass from the CRT and remove the old adhesive. 

Some of the early computer terminals are starting to exhibit this issue. 

 

[PB145B]

Well I do know that CRTS made in the 60s and even into the 70s that had Safety glass used a PVA bonding agent that fails and causes "Cateracts" in the front and the only fix is to heat the tube and slowly remove the safety glass from the CRT and remove the old adhesive. 

Some of the early computer terminals are starting to exhibit this issue. 

The original monitor that goes to the DEC Rainbow 100 suffers from this issue and it was made in 1982! You can see the cataracts in this image.

 

[techknight]

This has got to be the worst I have seen so far: 

https://www.ebay.com/itm/Vintage-Macintosh-Laptop-5300-series/332551182385?hash=item4d6d985831:g:i-MAAOSwLjxaf7TX

 

[PB145B]

This has got to be the worst I have seen so far: 

https://www.ebay.com/itm/Vintage-Macintosh-Laptop-5300-series/332551182385?hash=item4d6d985831:g:i-MAAOSwLjxaf7TX

:O  That polarizer is about ready to fall off!

 

[Byrd]

That looks like a real PITA to remove   Are you using any solvents/softening agents to peel it off?  Where will you source a replacement polarizing film from?

 

[K55]

The way we used to do it with old game boys (DMG's) was to use a razor blade to separate the digitizer/polarizer with a razor blade and peel it off, then clean the residue with 99% rubbing alcohol and align a new polarizer. Considering that the polarizer already looks like its done all you need to do is peel, clean, get a big sheet of polarizing film and some LOCA glue and have a polarizer that will last another 100 years.

 

[techknight]

Now, where do you source polerizers? 

I found one site, but they are different as far as degree angles, etc. Guess YMMV might apply there. 

 

[CC_333]

Now, where do you source polerizers? 

I found one site, but they are different as far as degree angles, etc. Guess YMMV might apply there. 

I guess if one could find a sheet big enough, they could turn it to the exact angle they need, and trim off the excess?

It's spectacularly wasteful, but it's something?

c

 

[MOS8_030]

Looks like someone left that sitting in the back window of their car in the summer....

 

[goncalo]

Now, where do you source polerizers? 

I found one site, but they are different as far as degree angles, etc. Guess YMMV might apply there. 

I'm so relieved having discovered my damaged LCDs can be fixed!

I've noticed several sellers of polarizer film mention degree angles - does anyone know the angle for the MB 1xxs?

Has anyone bought and applied this polarizer film?

SHARP LM 64P58 assembly removed from the backlight unit:



The polarizer film peeled off:



LCD with the adhesive still on:





Adhesive peeled off and flat blade:



Finished LCD unit:

 

[Franklinstein]

I'm glad people are trying to replace the polarizers on these displays. I may have to try it myself, though an internet/eBay search usually turns up a suitable replacement LCD for a reasonable sum.

I'll reiterate since it seems to be a common theme lately: old batteries may be outgassing and/or leaking electrolyte directly onto the screens when stored which will likely damage the display. I have purchased several PowerBooks lately (160, 5300c, 5300cs, 190, 550c, 520) with screens ruined like this and all of them have had serious battery leakage problems. All of them have had different types and manufacturers of screens across several years of production. Now every time I buy a PowerBook I completely disassemble it to remove the backup battery and then store the computer without its main battery. I think the 1x0 series used soldered button batteries underneath the display hinge on/near the brightness/contrast controls so I'm not sure if that battery will pose as much of a problem as the later models which stored the backup battery underneath the keyboard or palm rest somewhere. iBooks of course use supercapacitors in place of backup batteries so they shouldn't suffer from this sort of thing if batteries are indeed the culprit (at least, not if the main battery has been removed).

Also, many LCDs have electrolytic capacitors somewhere, especially on older units, and they're probably starting to leak which can only make this sort of thing worse.

TL;DR: REMOVE THE BATTERIES, INCLUDING BACKUP. You'll save yourself a lot of headache in the future.

 

[Alex]

This is one very interesting post. Man I wish there was a wiki. I have to read this entirely as I have some of these affected models. I better go and check them out.

@Franklinstein, excuse my ignorance but what is a polarizer?

 

[Alex]

Ok, I feel pretty dumb, polarizer, as in Polaroid as in the film that is being peeled away in all this talk. Sorry about my complete fumble. I should read first instead of littering this gem of a post.

 

[digitalrampage]

I'm glad people are trying to replace the polarizers on these displays. I may have to try it myself, though an internet/eBay search usually turns up a suitable replacement LCD for a reasonable sum.

I'll reiterate since it seems to be a common theme lately: old batteries may be outgassing and/or leaking electrolyte directly onto the screens when stored which will likely damage the display. I have purchased several PowerBooks lately (160, 5300c, 5300cs, 190, 550c, 520) with screens ruined like this and all of them have had serious battery leakage problems. All of them have had different types and manufacturers of screens across several years of production. Now every time I buy a PowerBook I completely disassemble it to remove the backup battery and then store the computer without its main battery. I think the 1x0 series used soldered button batteries underneath the display hinge on/near the brightness/contrast controls so I'm not sure if that battery will pose as much of a problem as the later models which stored the backup battery underneath the keyboard or palm rest somewhere. iBooks of course use supercapacitors in place of backup batteries so they shouldn't suffer from this sort of thing if batteries are indeed the culprit (at least, not if the main battery has been removed).

Also, many LCDs have electrolytic capacitors somewhere, especially on older units, and they're probably starting to leak which can only make this sort of thing worse.

TL;DR: REMOVE THE BATTERIES, INCLUDING BACKUP. You'll save yourself a lot of headache in the future.

All of my batteries are removed and have been for 10+ years. This is not. Battery issue. 

 

[digitalrampage]

I'm so relieved having discovered my damaged LCDs can be fixed!

I've noticed several sellers of polarizer film mention degree angles - does anyone know the angle for the MB 1xxs?

Has anyone bought and applied this polarizer film?

SHARP LM 64P58 assembly removed from the backlight unit:

View attachment 24834

The polarizer film peeled off:

View attachment 24835

LCD with the adhesive still on:

View attachment 24836

View attachment 24837

Adhesive peeled off and flat blade:

View attachment 24838

Finished LCD unit:

View attachment 24839

View attachment 24840

Did you end up finding replacement polariser?

 

[goncalo]

Hi. This is a long haul project, it is on standby at the moment, sorry ;-)

 

[Paralel]

Anyone interested in a polarizing polymer that can be applied directly to the surface rather than as a sheet?

I talked to an old professor of mine who is an optical chemist, and he says he knows of a material that acts as an optical polarizer, it is applied to surface, and it polymerizes into a solid film on the substrate (surface) it is applied to.

I thought this sounded like something that would be an awesome and inexpensive (he said making up a batch is easy and inexpensive) way to replace the polarizing materials that seem to be failing on us.

A bonus would be that since it is applied to the surface of something, there is no air gap, so there is no risk of moisture intrusion in the future, and the polarizer is naturally hydrophobic, so any moisture that tried to get in would be repelled.

 

[Franklinstein]

I think the simple application of the polymer would result in a gloss style screen, not the matte style that we're used to on those old models. Personally I prefer matte screens for the glare reduction and the softening of the pixels (which are huge and blocky on those old displays). I wouldn't mind trying it on one, though, just to see how it would look. The question would become: how is the polymer applied? Is it self-leveling or does it require an applicator? Are there finishing actions required or is it good to go as soon as it's dried?