How to replace the LCD on a Sharp PC-1246/1247 pocket computer

here is how to replace the lcd on your sharp pc 1246 pocket computer sometimes the lcd might be broken sometimes there might be smudges on it due to the liquid crystal leaking out or humidity getting in and then you will need to replace the lcd so you can get replacement lcds linked down below so of course you're going to need your broken pc1246 and the replacement lcd you will also need ipa or isopropyl alcohol some lint-free wipes a small q-tip or cotton bud a sharp razor blade and this is going to be important later on and two fresh 2032 lithium batteries and they should be fresh not from the dead machine because if it was in the dead machine then maybe the batteries are dead too and you will also need a small phillips head screwdriver so let's get started so the first step is to remove the two screws on the rear now to take the rear off you can't just lift it off you have to sort of press from the top and on the bottom press only along the bottom so that you know you're sort of sliding the the rear back like this and then you can lift it up like that now it'll catch right so you push the back forwards like this and now you can remove the back it may take a little doing but you know don't worry there's nothing that you can really break on this okay so inside we have the battery compartment and if there are any batteries you can remove them by simply sliding the battery compartment up and then removing it now normally with lcd replacements i suggest that you put the batteries in and turn the machine on to see if there's any functionality at all for example if there's a speaker you can type in a program to to output beeps from the speaker the problem is that this has no speaker so 1246s have no speaker so there really isn't any way if you have a dead lcd to verify functionality that's why replacing the lcd is not a guarantee that you will end up with a fully functional pocket computer so the next thing to do is to remove all of these screws that you see over here now you might be able to see that the screws from the back are slightly different from the screws inside so this one is a slightly smaller screw okay now that we've removed all these screws the next step is to remove the plastic back so what we're going to do is we're just going to try to lift it up gently and again it may seem like it's sort of catching along the front edge so you can just sort of gently lift it out okay so here we go this is the interior here we have a grounding spring so the purpose of the grounding spring is to connect the ground of the pcb to the back of the of the machine that is the reset switch over here this is the contrast control this is one of the one of the chips and this is the external interface so what we need to do is lift the pcb out which we can do pretty easily we lift it out from the front and then gently pull it out and there's a hole in here for the spring that it may catch on so be careful all right now when we lift it out and we turn it upside down sometimes the lcd will actually stick to the pcb so just make sure that you keep the old lcd oriented as it should be you can now remove the rubber keyboard and let's go ahead and remove the lcd so we're just going to pry it off like that okay so this is where the lcd connects to the printed circuit board and it connects to the printed circuit board using this elastomeric strip now there is another elastomeric strip on the other side so it may be connected to the lcd it may be stuck to the lcd or it may be stuck up here the important thing is is that on these lcds the only connection is along the bottom side right there's no connection along the top side which means that the elastomeric strip over here along the along the the bottom of the lcd like this has the conductors in it and the other elastomeric strip does not so it's important to realize which one is which so we can just peel off the elastomeric strip set it aside there's your old lcd and there is a kind of a paper-ish bezel on it that's what we're going to remove next with the razor blade but first let's also remove this other elastomeric strip and this is really just a spacer so set that aside now over here there is also the polarizer now the old lcds these old lcds um only had a polarizer on the back and not on the front and that's why they had uh the polarizer as a separate piece the new lcds have the polarizer built in so you will not need the old polarizer okay now you might also get another little metal piece this is for the on off slider this is the on off slider right over here so the way that works is let's see so right over here along the top of the lcd right over here there are sort of four contacts and this piece presses against two of those contacts so it's sort of springy so it's really hard to put it on but in any case the point is that you can see that this thing has an orientation right versus this so when you put it back make sure that the um the the little legs sort of point up if you're putting it over here on the switch like that otherwise it's not going to turn on so all right so now we have the lcd um there is a bump on the side of the lcd right over here and it's important to notice where that bump is because the replacement lcd will need to be oriented in exactly the same way right there's a bump over here and the bump is on the right side of the machine so with the razor blade what we're going to do is we're going to very carefully stick the razor blade between the lcd and the bezel and the idea is that you want to dig in to the glue that's holding the bezel to the lcd but you don't want to tear into the paper it's it's not exactly paper it's sort of like it's almost plastic nevertheless there is always the danger that you will damage the bezel so just go very slowly and very carefully and just sort of rock back and forth and then just go all the way around the sides and what you want to be sure to do is keep pressure downwards that way you're not sort of lifting up on the razor blade and then digging into the into the plastic bezel and if you ever get to a spot where there is some resistance rock the razor blade back and forth and there you go so set this aside because you'll need it and this is the damaged lcd so that can go into the trash so when you're removing the bezel from the lcd be careful with your fingers and the razor blade don't be a paper that totally didn't happen to me okay so now that everything's apart and ready to go if you take the lcd and orient it the correct way with the bump now the bump uh if the lcd is facing up is on the right side if it's facing down it's on the left side of course um if you put the lcd just you know into the place that it's supposed to go you can see that it can shift back and forth which is a problem because these contacts are pretty fine and if the lcd gets shifted back and forth they won't make contact properly so what do you do well if you take a look at the bezel and you put it in you can see that it doesn't actually move back and forth this bezel is actually cut to fit pretty well inside this opening so what you will want to do is take the bezel and place it onto the replacement but before you do that there is always some plastic on the lcd that you will need to remove so let's do that now just peel it off that's just the protective layer so once you've done that take the bezel and put it on the lcd and sort of center it so you can see that there are these like tabs on the side the tabs sort of stick out on either side of the lcd and the lcd is just about big enough to fit inside the tabs so you know once you've done that you're pretty much good to go so the idea is what you could do is you could um put the bezel inside and then put the lcd on it maybe press it down a little bit lift it out take a look at it just make sure that the lcd does not stick out very much so this is probably pretty good okay so put the lcd back in now with the elastomeric strip um first of all let's deal with the spacer the spacer just goes on the top part so the spacer does have a rectangular um a rectangular outline so one side is narrower and one side is wider you want to set it up so that it's taller right so just stick it in there and there you go so the tall side goes up okay now here's the elastomeric strip and the the relative position back and forth doesn't really matter because the conductors inside are fine enough that it doesn't really matter but the thing is that you don't want any dust or dirt on this elastomeric strip so what i suggest you do um and i use a set of tweezers just to make sure that my my fingers don't get any dust on the elastomeric strip um but you know if you don't have a set of tweezers you can just use your hands and just make sure that your hands are clean so run some alcohol on the elastomeric strip this will just get rid of any dust that's clinging onto it because remember the elastomeric strip is a little bit sticky so i'm just going to use my tweezers and pull it through i'm going to use a fresh wipe and pull it through just to get rid of the excess and this is why lint-free paper towels are important because if it's not lint-free you're going to get lint on the elastomeric strip and that is going to interfere with the conductors so next thing next thing is again you will notice that this has a rectangular profile one part of it is thinner than the other make sure that it is pointing up the right way and you can sort of tell because um maybe you can't tell in the video but there's a sort of black line that runs along the top those are the conductors there's no such black line if you turn it on to its side make sure that the black line is facing up and then just put it in right there and just make sure that it is facing up okay you can actually gently press it down because again the strip is slightly sticky so it'll stick to the glass just make sure that it fits inside the uh the outline that it isn't like raised up or that it's not like diagonal or anything like that so so that should be pretty good alright so the next step is we need to find where the or the on off switch went so here's the on off switch okay so i'm just gonna put that back in okay and then we need to put the uh metal strip for the on off switch and there's a little hole in that strip so oops and there is a little post on the on off switch that that hole can go on to so once you've done that the next step is to put the printed circuit board back now what i like to do is just you know go over it with ipa just to make sure that all the contacts are nice and clean that there's no dust on them because remember this is not only for the lcd but also for the keyboard so any dust could interfere so just make sure that it's nice and clean okay now let's put the lcd back so we simply carefully drop it into its place okay and then because i'm slightly paper put the keyboard on first okay just tap it down gently make sure that all the buttons are in their holes now you can put the pcb on okay now it's in place now all we need to do is uh screw the pcb into place by taking the plastic part and putting it on now here again there's a hole for the spring make sure that the spring goes through the hole and then just press it down just to make sure that everything is nice and flat because the last thing you want is for it to rise up on one side and then you won't be able to put the thing back together again so so let's start with one of the center screws just to hold everything down then maybe we'll go with this far screw over here this far screw over here and let's see right okay next thing to do is uh we don't have to put the back on just yet uh we're going to put some batteries in so according to the diagram that's right over here we have one battery goes up with the plus side up the other battery goes down with the negative side up so do that and then take the battery holder and press in and down okay next thing to do is to turn it on and hey it works um now if it doesn't immediately um underneath on the bottom there's a reset button over here just press in with you know a screwdriver now it's important to actually test that all of the digits work so you know just hit some digits and we can see that something's gone wrong so you can see that there's an area over here where the digits just aren't showing up and that is basically a sign that the lcd needs to be shifted slightly back and forth so if i sort of uh move my fingers a little bit i think you can see that if i shift the lcd this way that the digits work if i shift it the other way the digits don't work so that means that i need to shift the lcd slightly this way so slightly to the left which if i turn it over will be slightly to the right so no worries let's just do that so here's what we can do to space out the lcd maybe a little better so here's the lcd we need to move the lcd a little bit so what i suggest we do is you can take this polarizer which you don't need anymore but it has a little bit of thickness to it and what you can do is you can cut some strips out of it as spacers so they don't have to be very big that's about the size of mine and what i'm going to do is i'm going to start with two spacers and i'm going to put the spacers up against what is now the right side and then i'm going to take the lcd and push it up against those spacers push it up against those spacers on the one side and then just press it down so that will allow us to and then i guess i can remove these spacers now so that will allow us to fine tune the position of the lcd and it will always be in increments of you know whatever whatever thickness this polarizer is so now we can do everything again and it's always important to remember to put the metal piece onto the on off switch so that the two little prongs face upwards and the hole is on the post now another possible symptom is rather than needing to shift the lcd back and forth pressing on the lcd will actually work so in this case what's happening is that the the elastomeric strip is not being pressed down far enough over time the elastomeric strip may actually deform a little bit because in on the printed circuit board the contacts are actually raised slightly so there are a few things that you can try one thing that you can try is to carefully remove the elastomeric strip flip it over and then put it back the other thing that you can do is well apply a little more pressure and the way we're going to do that is we're going to use our strip of and the way we're going to use that and the way we're going to try to do that is use our polarizing strip which again we don't need so the idea is that we're going to slip a piece of the strip underneath this bezel so that it applies just a little more pressure to the lcd now you might also be asking yourself well why don't we just use the polarizing strip and again the reason is that there is already a polarizer on it so it'll end up looking much darker so to do this i'm going to cut a thin strip along the long side of the polarizer just like that then i'm going to lift out both the bezel and the lcd then i'm going to put the strip on the bottom side and then i'm going to put the whole thing back and there we go that worked so the key was to shift the lcd properly using two pieces of the polarizing strip on the left side over here and one thin piece of polarizing strip on the bottom now it is kind of important to get that bottom piece as small as you can make it because otherwise it'll stick out and it won't look so good uh so if you want to take it apart and do it again that's perfectly fine to do you've got plenty of this plastic that you really don't need so that's pretty much it just put it back together again and you should be good to go you