New theory on the cause of the infamous Tunnel Vision problem - Testers needed!

[3lectr1cPPC]

I think you just have a completely screwed up screen honestly. It’s been unclear what the long term effects on tunnel vision on an LCD panel are. I wouldn’t be surprised if running the system with the display tunneled as bad as yours is long term can cause further degradation of the liquid crystals inside of the panel. It’s also entirely possible that the amount of baking you did could have caused this as well - hard to tell.
Point being I think at this point you need to source a new screen.

 

[Powerbook27364]

I think you just have a completely screwed up screen honestly. It’s been unclear what the long term effects on tunnel vision on an LCD panel are. I wouldn’t be surprised if running the system with the display tunneled as bad as yours is long term can cause further degradation of the liquid crystals inside of the panel. It’s also entirely possible that the amount of baking you did could have caused this as well - hard to tell.
Point being I think at this point you need to source a new screen.

I certainly don’t see this on the duo so far so you are probably right. It’s probably just due to the baking if I had to guess. I don’t use the 170 too frequently as my 145B is completely restored with the faster cpu card with fpu. The 145B also has a battery now so the 170 is probably going to be more of a shelf piece since it will never really need maintenance and there are no electrolytic caps in it.

 

[3lectr1cPPC]

The 145 battery will also work in your 170 in case you didn’t know - all 140 through 180c systems can use the same batteries.

 

[Powerbook27364]

Yep, I ran it for a while but it just isnt really worth using the 170 when the 145B display looks so much closer to white instead of green and does not tunnel in like the 170 does. Had no idea about the 160-180 models using the same batteries, i knew they shared some parts and didnt share others but i dont own one of those models. Just been referring to it as the 145B battery since thats what I primarily made it for and use it in.

 

[3lectr1cPPC]

Yep all 100 series besides the 100 and 190/190cs use the same batteries.
Interestingly enough my 170’s screen isn’t really green at all with the backlight on. More white, a bit yellower in person than in photos but it’s still not really yellow

 

[3lectr1cPPC]

The only real differences from the 140/145/170 to the 160 and 180 are:
Thicker display housings on color models
Slot in the back for the video out port
Larger front speaker “grate” on the middle hinge cover for the microphone and really that’s all. They have redesigned logic boards and such but they fit the same footprint. You can also swap displays between the 140, 145, 160, and 165 and the displays from the 140/145 will even display grayscale (from what I’ve heard) if they’re hooked up to a 160 or 165.

 

[Powerbook27364]

I wish tunnel vision could be completely solved. So many nice computers reduced to being unusable without extreme measures that may damage the display more. Reduces options from the 100, 500, and 200 series to the rare and more expensive color models, or the poorer display quality passive matrix models that often have lower specs and performance. I wonder if i can swap a color display into my 280 but i would probably need a new display casing too.

 

[3lectr1cPPC]

It’s not so bad. The upside is that it seems so far the active matrix monochrome and grayscale (not color) LCDs are immune to vinegar syndrome which is nice. And for most cases of minor to moderate tunnel vision, baking seems to be a sure fire and long term fix. Seems only in severe cases (like yours) that is fails. I’ve still yet to bake my 540’s display though. I’m waiting until I finally get a PSU recapped as I’d like to do long test sessions and my non recapped PSU craps out after running longer than 20 minutes and then it needs a break. Once I get that sorted it should be time to bake the screen, but my tunnel vision there is pretty minor. And my 170 is yet to be affected.

Honestly I don’t mind passive screens much. My most used 68k powerbook is my 145 believe it or not - even though I’ve got a 170 and a 180c. It’s got nice non stiff hinges, I’ve done the hinge mount fix, and it works perfectly. My others all have some sort of minor issue.

 

[Powerbook27364]

It’s not so bad. The upside is that it seems so far the active matrix monochrome and grayscale (not color) LCDs are immune to vinegar syndrome which is nice. And for most cases of minor to moderate tunnel vision, baking seems to be a sure fire and long term fix. Seems only in severe cases (like yours) that is fails. I’ve still yet to bake my 540’s display though. I’m waiting until I finally get a PSU recapped as I’d like to do long test sessions and my non recapped PSU craps out after running longer than 20 minutes and then it needs a break. Once I get that sorted it should be time to bake the screen, but my tunnel vision there is pretty minor. And my 170 is yet to be affected.

I forgot about the vinegar syndrome. I have gotten it on 6 displays so far, one 2006 macbook pro, one 2003 dell laptop, 4 2009 asus monitors. Nothing else so far and the affected displays are gone to avoid them affecting my other computers. I wonder what makes them immune... Strange that the layers are failing on the hosiden panels but not the polarizer. Have there been any affected hosiden displays yet?

 

[3lectr1cPPC]

I even made a dedicated thread asking if anyone has seen it - no one has. Another thing to note is that I browse a LOT of eBay listings for PowerBooks. I’ve seen every single passive matrix and active color PowerBook from the 90s with it in a listing at least once - but not once a Hosiden mono/grayscale panel.

Also wow you’ve gotten unlucky with screens. I’ve yet to hear someone get it in a display that new (2006 and 2009) but it’s certainly possible. Same type of film was being used then.

 

[Powerbook27364]

Well thats certainly a benefit of the hosiden panels then. I just need to keep buying some more until my luck improves and i get one without any tunnel vision. 2 buys so far and both are extreme lol

 

[3lectr1cPPC]

Yeah…
More notes on Hosiden - they absolutely made other LCDs, Color TFT. From a page I found they were used in a lot of thinkpads of the time, including the 701c! No signs of tunnel vision there thank god - but NONE of vinegar syndrome either. I’d think with how popular the 701c is I’d find at least some mentions, but NONE. Makes me think they used a different type of polarization.

 

[Powerbook27364]

Yeah…
More notes on Hosiden - they absolutely made other LCDs, Color TFT. From a page I found they were used in a lot of thinkpads of the time, including the 701c! No signs of tunnel vision there thank god - but NONE of vinegar syndrome either. I’d think with how popular the 701c is I’d find at least some mentions, but NONE. Makes me think they used a different type of polarization.

I wonder if there is any information into that because if people could replace failing polarizers with ones that (at least currently) have no record of failing, it would be really nice for long term reliability

 

[3lectr1cPPC]

Modern LCDs use a different film I remember reading somewhere a while back… not sure though. And also if it would be compatible with older LCDs, which I’d think it would be.

 

[3lectr1cPPC]

It would be nice if we could find some chemical evidence of what type of film Hosiden used though, just for interests sake. Their displays are always a wild card - not very common in 90s laptops and they seemingly left the space after that. All the others have Sharp, Hitachi, Samsung, Toshiba, or ToriSan (Sanyo) LCDs which all get vinegar syndrome.

Edit: according to Wikipedia at least they still make LCDs but I’ve never heard of them being in any laptops past the 90s.

 

[Powerbook27364]

View attachment 50544
I don't think I posted this before but this was the initial tunnel vision effect for reference if anyone wants to know.
took about 30 minutes to fully tunnel all the way in.

So, I was just looking back through the thread and i noticed the weird display problems were definitely not there before so I think that confirms baking damage. Maybe my oven is a little bit off on temperature.

Also, there is a bit of a weird behavior on my duo. The display tunnels pretty quickly most of the way in, but the burn in is significantly less than the 170 ever was. It is kind of like a lighter burn in. It still burns in but is less noticeable and once the area of the display is fully tunneled it lessens even more to the point where it is harder to notice and not too bad to use.

 

[3lectr1cPPC]

That burn in differences may have something to do with the duo being grayscale and the 170 being mono. My 540 has light temporary burn in but it’s only mainly visible on off angles and maybe directly after I close a window that’s been open for a while.

 

[Powerbook27364]

That burn in differences may have something to do with the duo being grayscale and the 170 being mono. My 540 has light temporary burn in but it’s only mainly visible on off angles and maybe directly after I close a window that’s been open for a while.

I will have to test how long the burn in lasts. I would hate to damage the display by baking if the burn in is only for a short time. I can see it no matter what angle I look at, but it definitely is more pronounced when looking at an off angle.

 

[3lectr1cPPC]

Here’s it visible in an old photo:


Might have posted it in this thread earlier - unsure.

 

[Powerbook27364]

Here’s it visible in an old photo:
View attachment 56829

Might have posted it in this thread earlier - unsure.

I only seem to get burn in on the duo in the affected areas, but that may just be because I have not tested it enough. I will have to test alot more before making any choices to bake or keep.