On 03/03/2014 1:39 AM, Sjouke Burry wrote:
On 03.03.14 9:18, John Robertson wrote:
On 03/02/2014 1:26 PM, Sjouke Burry wrote:
On 02.03.14 22:04, N_Cook wrote:
On 02/03/2014 20:25, Sjouke Burry wrote:
On 02.03.14 13:55, N_Cook wrote:
Cause and any amelioration, short of draining the liquid and starting
again (for elfin safety in nothing else), and of course unobtanium
replacement displays
Where I used to work a batch of early large LCD display Philips DVM
meters for the engineers.
Every now and then , despite warning labels, someone would leave
one in
direct sunlight (UK version) for a while and the display would become
next to useless, permanently.
Presumably the LC migrates out of its assigned wells and does not go
back in them. Anyone know of a localised heat/cold/pressure
treatment or
something like that ,at least, won't make matters worse , and may
actually improve the splodge a bit?
Apply 30 atm in a pressure chamber, then wait a few hours.
makes some sort of sense, I always assumed the sun-heating business was
making the fluid expand and force open the seal between the glass
sections. OK, so apply your high and even-handed pressure but how to
stop the glasses separating again?
The fluid tends to stay in place,it likes the glass sheets.
Years ago I made lcd glasses, to switch the visual field
in experiments.
Production:Separate the glass with a thin mylar film(dupont),
glue two opposite sides with 5 min epoxy, remove the mylar,
then put a small drop of lcd fluid on one of the open sides.
And a miracle happens, the drop gets sucked between the
glasses(~10 minutes) very slowly.
Then clean the open sides, and apply epoxy to them as well.
Worked for me.
So only pressure or heat tends to drive the fluid out.
Bad mounting can cause unwanted pressure and damage.
The air pressure repair works, if the fluid is still present
around the leak, else you are out of luck.
I could see using a vacuum pump first (LCD in a bath of fluid) to draw
out any air. Then, with the LCD still bathed in the replacement fluid,
pressurized to the 30ATM to force the liquid back in. Then seal with
whatever works best.
John :-#)#
You cant replace the fluid, the pressure treatment
just tries to force back in what was there in the first place.
Maybe.
The fluid had a price tag of 500 dollars for 4 cubic centimetres,
and has wildly different specs for various lcd's, so
forget getting new fluid.
My lcd's switched between transparent and milky, and did not
use polarization.Working voltage 500 volt AC!!!!! on/off.
Also checking the mount for unwanted pressure points
does improve things.
Ah, thanks, that clears up why no-one is resurrecting them...
John :-#)#
--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."