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550c Screen Stain?

LCARS

Well-known member
I've had this 550c for almost two years and I'd say this "stain" appeared about three months ago. No change in location: out of the sun in a climate-controlled office. It came out of nowhere as far as I can tell.

There does appear to be a stain on the plastic bezel but I'm not certain its related. There does not seem to be any noticeable effect on the display when on. I haven't tried an LCD cleaner on it yet; I thought it might be better to get some thoughts on here.

IMG_1593.jpg
 

LCARS

Well-known member
So you haven’t tried wiping it off yet?
Lightly with a fine microfiber edge with no change. Before I try rubbing alcohol or anything else, I wanted to post the image/question here. With the recent examples of other PowerBook displays losing polarizing film and such, I'm worried about making it worse before knowing more.

It really did appear over night. I didn't see any initial signs. It doesn't move and the space is seldom used so I know it didn't come from anyone or anything (that I'm aware of).
 

LCARS

Well-known member
🥺 No! Say its not so. To this point, I haven't seen any 5xx active matrix with vinegar syndrome. A quick search has given me hope that should this be the case, its not the end of the panel. Is that the general consensus?

I tried to remove it today and sure enough, its not on the outside : / It feels like I just got this machine operational. @techknight have you replaced polarizing film before?
 

Daniël

Well-known member
I haven't seen any 5xx active matrix with vinegar syndrome
One of my 550c displays did have it. You could hunt for a 5300c parts machine for a replacement display, they are mostly the same. Although the one I used from a dead 5300c had the display connector in a different spot from the 550c vinegar'd panel, so the internal cable is a bit coiled up which I'm not a fan of.

The main fear I'd have is vinegar syndrome spreading to other machines nearby, which apparently can happen. But if it's not on the polarizer, it might not be VS at all.
 

LCARS

Well-known member
The main fear I'd have is vinegar syndrome spreading to other machines nearby, which apparently can happen.
Yikes, I didn't realize that. That's an unsettling thought (looks at all the PowerBooks next to the 550c).

As of now, the stain is not visible when the display is on and isn't presenting the issue that far gone display do.
 

techknight

Well-known member
🥺 No! Say its not so. To this point, I haven't seen any 5xx active matrix with vinegar syndrome. A quick search has given me hope that should this be the case, its not the end of the panel. Is that the general consensus?

I tried to remove it today and sure enough, its not on the outside : / It feels like I just got this machine operational. @techknight have you replaced polarizing film before?
No, i have not. because I have not personally encountered a machine with that problem. BUT... I do know that it will happen someday, as adhesives just naturally break down over time. it just, is what it is..

Look up 60s/70s color TVs and the PVA safety glass bond.
 

Byrd

Well-known member
The main fear I'd have is vinegar syndrome spreading to other machines nearby, which apparently can happen. But if it's not on the polarizer, it might not be VS at all.

That's a fairly long stretch there, it's not like it's some evil strain taking over our precious PowerBooks! It appears common under particular storage conditions, and countries, notably older machines originating from Japan.

A similar phenomenon occurs with early PowerBook 100 displays - a kind of purple/red bloom that leeches from the centre of the screen - this is related to the mouse ball pushing slightly on the LCD over several years causing small microscopic cracks that eventually the liquid in the LCD escapes. It looks like some sort of environmental change but it's not.

@LCARS what you have isn't the syndrome - see pics of this, it's a lot worse than what you have. Not the end. One of the top layers has slightly delaminated away from the LCD.
 

LCARS

Well-known member
@Byrd thank you. That makes me feel much better. It didn't seem to be the same issue but I'm also not familiar with with. Before I get too comfortable, is this also likely to be an unfortunate outcome? Or does this issue tend to stay localized?
 
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