 Greetings pocket computer friends. Here's what you're going to need in order to replace the LCD on a TRS-80 PC3 or its equivalent, the Sharp PC1250 series. You're of course going to need your pocket computer with bad LCD. You're going to need a replacement LCD, which you can get in the link below. You're going to need a set of small pliers, a set of precision screwdrivers, some tweezers, some cotton wool buds, also known as Q-Tips in the United States. You're going to need two fresh CR2032 batteries, a plastic ziplock bag, some latex or nitrile gloves, IPA or isopropyl alcohol, 99.9%. Some acetone, a glass container for the acetone. Acetone eats plastic, so you're going to want to stay away from those Tupperware containers. And some lint-free tissues. Here I'm using chem wipes. Okay, so the first thing we're going to do is test the device to make sure that everything except for the LCD works. Because if something else is broken and you replace the LCD, well, you've still got another problem and you may not actually get a display on the LCD. So let's test it first. So turn it upside down and you'll see that there are these two screws that you will need to remove. So hinge the case up like this and then release it from its tabs. And you'll see this nice diagram for the battery compartment. So in order to get the batteries out, if there are any batteries, you're going to simply press on the battery compartment cover forwards and then you can lift it. Now, if you've already got batteries in there, you probably just want to take them out and replace them with fresh batteries. Because again, if you don't know that those are fresh batteries, you may still have a problem. So put one battery in positive side up, the other battery in negative side up. Replace the cover by pressing down and pulling towards you. And then you don't actually have to replace the cover at this point because you're going to need it off for the next steps anyway. So turn it around and put it into the run position and type beep 2, B E E P 2 and hit enter. And you should hear two beeps. Now, if you don't turn the machine over and push this little recess over here, which is the reset switch. You can see that is labeled below all reset. So that goes here. Just push it in, turn it off, turn it back to the run position and just try again. And if you can't get it to beep, try the reset again. And if you still can't get it to beep, make sure that the switch is in the run position. And if you still can't get it to beep, then you've probably got another problem in which case replacing the LCD will help to replace the LCD. But you've still got some other problems to deal with. Next, we're going to remove the batteries. Now, the next thing that we're going to do is remove the screws from the memory module. So there are three screws and they're the same size as the screws holding the back on. So there's no need to keep them separate. And now you can lever the memory module out and it may require a little bit of persuasion. So there's the memory module and these contacts are where the elastomeric strip goes in order to make contacts. So you're going to want to clean that eventually when we put the unit back together. And there is the elastomeric strip right over there. So the next thing is to remove the screws from the plastic backing. So this unit only has one screw but other units may have more than one screw. And then you're just going to, you may have to lever it out a little bit. But hinge it up and then just pull gently on it and eventually it'll come out. Now, don't yank on it because the speaker is connected to it and the speaker wires are right over here. And if you bend it back and forth the wires may come loose in which case now you've got a soldering job to do. Okay, so that's that part. So next what we want to do is lever the entire PCB out. Again, hinging it forward and now be careful because you don't want to drop anything. Especially not this part which contains all the keys and they're all loose. So if you hit this and the keys go flying, well, I hope you took a picture of the way the keys were on the keyboard. Okay, so now this is the unit here. So we can pull off this rubber keyboard device and we can place that over on top of the keys. And these are the contacts for the keys and you can clean those later as well. And these are the contacts for the switch which are usually a little bit corroded and we can clean those as well. So now we need to get the LCD off. So the way to do that is, again, carefully move the back away. Now there are eight tabs holding the LCD bezel in place. One, two, three, four, five, six, seven, eight. There are also tabs on the side. There's one tab and the other tab is just under this dial, just under the contrast dial. Those aren't bent over so you don't need to worry about them. So in order to take it out, what we're going to do is very carefully stick a small screwdriver underneath the tab and carefully bend it upwards. And you want to be a little bit careful, especially around the area where there may be some traces. Because if your screwdriver slips and goes across those traces, well now the traces may be broken. And then you've got another little soldering repair job to do. Be especially careful around this area because there's a processor here with pins and there are other traces around it. And you might want to use an even smaller screwdriver for that. Okay, so now we've levered all eight tabs so that they're pointing up. Now to remove the LCD, simply flip the unit over and then get your screwdriver again. And we're simply going to pry gently at the bezel from one of the sides. Or from the bottom maybe. And it's going to be a little bit sticky. Okay, and just lever both sides up because again it's going to be a little bit sticky. Okay, so that's it removed. And again, these are the contacts that touch the elastomeric strips in the LCD, which make it work. So we're going to clean that when we put the unit back together. Now we can place the PCB aside and now all we have left is the LCD itself. So we're going to take the tweezers and I'm just going to take some lint-free towel just to get that ready. And what we're going to do is we're going to pull the elastomeric strip off. Now it may have been left on the PCB, but in this case it's in the LCD compartment. So let's just pull it out. Again, it's sticky. So just pry it up from one of the sides and just peel it right off. You're going to need it, don't lose it. Same thing with the other elastomeric strip. Now I'm handling this literally with my hands because we're going to clean it later. But right now we don't need to clean it. Okay, so what we have left is the bezel and the LCD. And there's actually a plastic top on top of this that we're going to remove. Now you can't just take the LCD out because it's actually stuck down to the bezel with adhesive. So what we're going to do is we're going to place the LCD in the plastic bag, pour acetone into the bag enough to cover the LCD, put the bag in a container so that if the acetone leaks out, it doesn't go all over the place and melt other things. And then we're going to leave it there for about an hour or two. And what that will do is it will loosen up the adhesive enough so that we can press the LCD out of its bezel. And now we just start a timer for an hour or two. You can check after an hour to see if you can gently press on the LCD to get it to come out. If it doesn't seem to come easily out, just wait for another hour. Okay, it's been about an hour so let's go ahead and see what we've got. So we do have one piece of polarized film which we will not need because that is integral to the new LCD. So I'll just set it aside. Okay, I'm just going to push gently to see how loose this is and it's really not very loose at all. So I'm just going to leave it in here for another hour and come back later. Okay, another hour has gone by. Let's see where we are now. Okay, it's loose or it's loosening a little bit. It could probably stand to be in there for another hour. The edges are actually flexible but the middle of it is not yet. So the acetone hasn't really penetrated to the center over here. So I'm just going to leave it in for another hour. That would be three hours total. Alright, so it's been another hour. Let's see what we've got. Okay, this came off quite nicely. So usually what happens is, first of all we don't need this LCD anymore because it's dead. So usually what happens is you will see a strip of adhesive on both sides of the bezel. You can leave it there or you can scrape it off either way. It doesn't really make that much of a difference. On the top there is another strip of adhesive which held the top polarization strip and you don't need that. So I would definitely recommend that you just clean that off. Now we're just going to set this aside and you can dispose of this down the drain with plenty of water. Now the next step is to clean up the contacts here. So we're going to take our isopropyl alcohol and a Q-tip and I have a dispenser of IPA. This is the kind you see in the doctor's office. So they push down on this and IPA comes out. IPA is supposed to come out. Maybe I just need to refill it. So now we just scrub and while we're at it we may as well just scrub the keyboard contacts as well. And the switch contacts also could use a little bit of cleaning. Yeah, those switch contacts were pretty dirty. So now they're nice and clean. Okay, the next step is to place the new LCD into the bezel. Now it was very important to note the orientation of this little dot right here. So the orientation of the dot is this way. So it would go on like this. And the second thing is the orientation of the LCD. And the LCD has sort of like a little glass bump on one side. Also if you look in the light you can see that there is a gap in the contacts over here which matches up with the gap in the contacts over here. So that means of course that the LCD would go like this and the bezel would go like that. So before we do that there is a protective film that you need to remove from the top of the LCD. Now don't be deceived when you pick at it and you feel something else. That's actually the top polarizer. What you're really interested in doing is getting rid of the top piece of plastic protective film. So now because the bezel is oriented this way and the LCD needs to be oriented this way then all you have to do is turn the LCD over and place it inside the bezel just like that. And you can press it down a little bit if you've still got that adhesive in there. Now the next step is to clean the contacts on the LCD. So we're going to do the same thing with some IPA and a Q-tip. And you don't want a lot so just be sure to squeeze off the excess and then just lightly run once over the contacts and then use the other dry end to just dry it off. And the reason you don't want a lot is that you don't want the alcohol to go underneath. The next step is we need to take these elastomeric strips and place them back in the LCD. Now first we need to clean the strips. So to do that we're going to take another piece of lint-free paper towel and we're just going to add some alcohol to it maybe to both sides and then we're going to pick up the elastomeric strip with the tweezers so that we don't touch it with our oily fingers and then we're just going to pull the strip through the paper with the alcohol on it and then we're going to place it onto the contact area and lay it down just like that. Now the orientation up and down doesn't actually matter so much. What does matter is that you can see a little black line that runs across and that needs to be facing up, up and down. And I just like to run the tweezers down one side and then press down because the elastomeric strip is sort of naturally sticky. So this gets it positioned nicely and straight and now it's in there. So we can do the same thing with the other side. It doesn't matter which elastomeric strip goes where. I see a tiny bit of dirt. So the black strip is electrically conductive. So if there's dirt on top of that black strip then there will be a contact on the LCD that doesn't actually make contact and that's not great. I'm just going to press down a little bit and I'm just going to put my tweezers between the bezel and the strip just to get it to line up a little more straight. Again it doesn't really matter if it's a little curvy. So now that we have the strips in the LCD module, all we have to do is place it back onto the PCB. So to do that, keeping the orientation correct, we're just going to rotate it and then place it so that the tabs go right back into their holes. And of course I got the orientation wrong. The hole goes that way. There we go. So now we're going to carefully turn the PCB over and we're going to press down and now what we need to do is bend the tabs back over. And now what we need to do is bend the tabs back over. So for this I'm going to use the pliers and keeping pressure, downwards pressure onto the LCD, I'm just going to bend the tab over and that tab I'm going to have a little bit of problem with because I can't reach in there. So I'm just going to do the other side now remembering to maintain pressure. Okay now for the one that I can't really reach I'm just going to use my screwdriver to lever it down and then use the pliers to go the rest of the way. Okay and that's the LCD installed. So now we can put the cover back on. So before we actually put the back plastic on, what I'd like to do is take another Q-tip and some IPA and clean the contact on the memory card for the memory card. Okay and there's an elastomeric strip that's sort of sandwiched inside here. We can gently go up and down with the alcohol. And I don't think you really want to press very much because then the strip may fall out and then you have to put it back in. So I'm just going to dry it with a fresh Q-tip. Okay and that's how that would go like that. So the next thing that we're going to do is we're going to take the keyboard side and make sure, do I have this in the right way? Yes, we're going to place it. Okay so there are these two little things here which go through the holes in the rubber pads. So just make sure that's done. There is this piece of metal here which is another bezel. You can just leave it there. Okay notice that it does actually move and it actually has a little seating point where you can feel that it's in its place. So the next thing that we're going to do is rotate the PCB and put it in from the bottom first or from this side first. Make sure it's in place and then just press it in. Just like that. And do the same thing with the plastic. We push it in there and then press it down. Okay so the next thing is I'm just going to take one screw and put it back into the plastic part. Put the plastic back just to secure it in place. Now we have the memory card. So again, we can just put some IPA on the contacts and then dry it off and then place it face down into its place. And it should just drop into place wherever it goes just like that. And then use the three screws to screw it back in. It doesn't have to be really tight, but it just needs to add enough pressure to the board to push down on that elastomeric strip. Okay. The next thing that we're going to do is we're just going to put the batteries back in. So plus for the top one, minus for the bottom one. Put the battery cover back into place. I guess it only goes in like this. And then just for good measure, we're going to press the reset button, turn it around, put it into the run position. And you can adjust the contrast. So there we go. We've got contrast and now we can just go beep to. And everything's working properly. So let's put the back back on. So again, we sort of, there are these hooks here that hook in this way. So hook it in there and then make sure that it hinges down and feels good. Screw the two back case screws in and there you go. We have a newly working TRS-80 PC3.