Tunnel Vision On Monochrome Active Matrix Powerbooks

[Shaddam IV]

I could try turning on the Powerbook as its screen is being toasted… what do you think?

 

[3lectr1cPPC]

I'd let it cool down first.

 

[Shaddam IV]

I've now let it run for 2 x 6 hours. I let the screen cool down and tried it. No change (tunnel vision is still creeping in after a few minutes). Maaaaaybe a bit slower than before. But it has the same extent. So I'll keep toasting the machine.

 

[Shaddam IV]

The result of this experiment is: The IR lamp does not sufficiently ameliorate the tunnel vision. I'm stopping now. Interestingly, the screen didn't get any worse either, although it's been exposed to a lot of heat. If the tunnel vision effect is really caused by moisture, that moisture apparently doesn't (possibly because it can't) escape from the inner areas of the display when heated.

 

[Shaddam IV]

I put a 180's screen with moderate tunnel vision in the oven at 98°C for 12 hours. The tunnel vision effect is much slower to appear now, but appear it does (after 30 minutes or so). My conclusion is that the liquid crystals themselves are degraded, and that short of cracking open the panel, scraping out the liquid crystals (they appear to look like goo), and putting in a new layer, there is no permanent fix. I have no clue as to how to open an LCD to get the crystals out short of breaking it apart - so I'm giving up for now.

 

[Paralel]

I put a 180's screen with moderate tunnel vision in the oven at 98°C for 12 hours. The tunnel vision effect is much slower to appear now, but appear it does (after 30 minutes or so). My conclusion is that the liquid crystals themselves are degraded, and that short of cracking open the panel, scraping out the liquid crystals (they appear to look like goo), and putting in a new layer, there is no permanent fix. I have no clue as to how to open an LCD to get the crystals out short of breaking it apart - so I'm giving up for now.

Replacing the LC in the screen is impossible. The glass sandwich part of the screen can never be taken apart successfully.

 

[JCAHCULL]

¡Bingo! Sí, eso es catalán. Soy de Barcelona. No se tradujeron muchos sistemas operativos al catalán. Sólo 7.1 y 7.5.3 creo, o al menos así es. Y luego nada hasta León.

Sobre la pantalla, creo que se puso negra mientras estaba en el horno, era difícil de ver. Lo mantuve entre 80 y 90ºC durante unas seis horas dos veces. Temperatura por encima del punto de ebullición, para evitar la expansión de gases y lo dejo enfriar toda la noche dentro del horno. No abrí la puerta durante el proceso para evitar cambios térmicos bruscos que pudieran romper la pantalla.

No sé cómo volver a sellarlo. De hecho, no desarmé la pantalla en sí. Leí en otro post a alguien que lo intentó y no le fue muy bien, así que enmascaré la parte de atrás de la pantalla con papel de aluminio y toda la pantalla dentro del horno. Lo mejor que se me ocurrió para evitar que esto volviera a suceder fue mantener las bolsas de sílice adentro.

 

[JCAHCULL]

Buenas Tardes, Tienes todavia los disquetes en Catalan?, estoy rescatando del olvido mi viejo PowerBook 170, y ya con el BlueSCSI instalado el silencio despues de quitar el disco duro es de agradecer, soy de Barcelona tambien, mis disquetes son de la version 7.0.1, en castellano, lo proximo sera hornear la pantalla, no esta muy mal pero padece del mismo efecto tunel que todos los PowerBooks 170. Dispongo aun de los cables SCSI y un lector Iomegazip SCSI, que sustituire con el BlueSCSI de 25 pin que funciona muy bien.