PowerBook 170 Dark Corners

[MJ313]

I'd be really curious about throwing it in a small room with a dehumidifier for a good chunk of time. I have a dehumidifer... just no 180. or 170. or anything else with this issue.

Then vacseal that thing right up.

 

[Rajel]

Huh, vacseal. Never heard of this stuff until now.
Cool, was going to ask what people were using to re-seal the screens.

 

[marcushe]

How do you reseal the screen?

I have recently ruined two decent PowerBook 180 screens that had minimal dark edges, trying to reseal. I used Imperial Vacuum Sealent because it was much cheaper than vacseal.

However both screens now still work but are completely distorted with black boxes, lines, and blurriness. Whats funny is if I leave it on - despite the distortion - the edges are not getting dark.

I thought the first screen was overbaked in the oven (190 degrees for 5 hours) - but the second screen I did not bake, and the same issue happened.

My process was:

1. Removed display / backlight assembly from the PowerBook case.

2. Used a pliers to turn the 30 notches on the back of the backlight assembly and remove the screen

3. Used painters tape on the screen glass, and put sealant around the back of screen. Waited two days.

4. Put screen back on backlight assembly, moved notches back into place.

5. Turned on, Screen ruined.

I have tried using a toothpick and some isopropynol (alcohol) to remove the added sealant from between / under the black spongey pad and the glass on the back of the screen. I was hoping it was just the sealant causing an electrical conductivity issue with displaying the data - as the black spongey bar seems to atually be a conductor to some pins for display data. However, removing the sealant from the screen (which comes off like flaky plastic) did not revert the screen to normal.

For now I have two ruined PowerBook 180 screens that I wish I would have never done anything with.

If you are going to try and seal the screen - I would not remove the screen from the backlight assembly, and instead just try putting sealant on the display corner openings, instead of fully removing the screen from the assembly. It seems if the screen is removed from the backlight assembly, it is runed.

 

[techknight]

Well then it appears whatever adhesive/sealant you did use was solvent based, and that will eat up the ribbon cables and its bonding to the LCD glass itself. Hence why you have this failure. Your only other option (with a new display) is silicone maybe? 

Edit: Nevermind. these displays have the zebra stripes that bond the glass to the base PCB. 

You have to clean the crap out of the glass connections, the PCB, and the zebra strips(elastometric connector) themselves, and then you have to turn the metal taps that hold everything together super super tight. they cannot be loose. Also the alignment has to be dead-on. 

 

[techknight]

Also, read THIS: https://www.eham.net/ehamforum/smf/index.php?topic=40151.5;wap2