|Cleaning the LCD|
Message #11 Posted by Vieira, Luiz C. (Brazil) on 6 May 2003, 5:06 p.m.,
in response to message #10 by R Lion
you may be right, unless its stated that:
"Procedures below assume you are acquainted with the process; do not try it unless you have the skills or you may damage your calculator!"
It does not apply to you, Raul, of course. PLEASE, read everything first as many times as you think you need before trying. It's harmless if carefuly done.
The major concerns are:
1 - Electrostatic discharges; take your safety precautions
2 - the two small springs that connect both bezels to the back label
3 - keep track with removed parts and be aware of alignment, etc.
You see a metal frame around the LCD and it has four locking tabs on the top and another four on the bottom, and they lock the complete assy to the mainboard. You should carefully unfold (partially, not to straighten them) the tabs so you can remove the frame; keep the mainboard with the IC's on the top and the LCD on the bottom, for safety. Be carefull not to allow the LCD fall on teh floor and cracks...
After rmoving it, take the two polymers and carefully inspect them for dust and dirty particules. Clean it with the best cleaner you have (I use alchool and, while it's not yet dried, I remove the exccess). Look at both conductive surfaces and check with reflexive light so you can "see" if it is homogeneous. It's also a good practice to clean the LCD's contact surface where the polymers touch it.
Rebuilding it needs patience: replace the polymers in their original position (they do not have a left- or right- prefetrence alignment, just place them as they were before) and then it's time to "push" them back.
First try to insert the complete set at once, gently twistint the tabs so they will all be in place at the same time. If you do not succeed doin that (I seldom do), you insert the lower part first (wtih the holes in the mainboard) and then the upper part (that borders the mainboard). Before you lock the tabs back (gently folding them as they were), chaeck if the polimers are aligned with both the LCD and the contacts in the mainboard. If you "see" they are twisted, try to pull the LCD assy back a little enough the polymer realigns itself. If it is twisted, may some segments be off.
If you are sure the polymers are in place, fold the tabs back and replace the mainboard. Remember placing the (-) pole spring. Place the batteries and try the [ON]&[×] seftest and check if everything lits. If not, you may need to remove the LCD assy and check again for cleaning OR simply checking if the polkymers are not folded or twisted.
It's sometimes time demanding and tedious, but I have rebuilt all Voyagers of this type successfuly. I cannot say the same about the flex-circuit type.
If you are in doubt, don't do it. Try with a broken voyager first before doing. Anyway, you may succeed. I do!
luiz C. Vieira - Brazil