Hi in a video on my main channel I repaired this uh, fluke 23 and well, I'm just touching the random circuitry here and it's causing it to go haywire. Of course it is. And the Lcd has this issue in the background. Like this, you can see that the uh, the contrast is still brilliant on this.

It's like, absolutely awesome, But that background is absolutely hard and I took the Lcd out. And of course it seemed to be embedded in the Lcd. But there's a few people who I said, hey, you may still be able to fix this. Um, by trying to actually remove the uh, silver backing on this.

The reflective backing. Because this is a reflective Lcd, it's not transmissive or anything like that. I've actually done a video on Lcds um, which I'll link in. So I guess here is a before shot and we'll have a look afterwards.

Uh, I'm not going to be. I'm not sure I'm going to actually be able to do this. I could actually make it worse. ruin it.

Um, but you know I it's worth a shot just for educational purposes. So we'll just, uh, get the clips off there and that will get our Lcd, get access to the Lcd and then we can lever that out. The Elastomeric zebra strips. I just meant better to call them zebra strips.

Try and try and pronounce pronounce elastomeric. Actually, that's not bad. I can sometimes, I just can't do it. Um, someone actually asked in the previous comments, how do you reattach these uh, zebra strips if they come off? Well, the good thing about zebra strips is that you don't have to worry about it.

There are. They're actually not the only thing holding it on there is just its natural. um, like it's not even natural stickiness. It's just like rubber like in long term.

it's just sort of, um, you know, sort of like held itself on there. But there's actually nothing attaching that. And the thing with um, elastomeric or zebra strips is that they might need the hang on might need the macro lens. There you go.

You can see that the there are individual little contacts on there so we're zoomed in quite a bit. And of course you can stretch that. I'm stretching that like that. And this means that it gives you many, many different contact points for at the same scale.

There it is at the same scale so you can see how many contact points there are for each pad in there. So alignment of these things does not matter. There's that's a good thing about them. There's so many of them in there.

These little, uh, like their carbon or whatever they could be. You know, I don't know what actual material, some sort of, you know, some sort of conductive carbon, uh, type thing is embedded. These little strips are embedded in there and they go all the way through to the other side and they just press fit, make contact. They just push against the surface and that's why if you ever have like a faulty Lcd with you know, a couple of segments of missing or something like that, it's probably the uh, pressure on the zebra strip here.

Actually, you know, causing that, uh issue so you can get in there, resettle it. maybe tighten the screws up to put a bit of, uh, extra pressure down, maybe wipe the contacts on the Pcb and stuff like that. So so there's absolutely no worry about realigning these because they just sit in there like that. and then it's the pressure of the screws and and the actual design of the housing.

Um, you know, the certain pressure of the in this case, between the Uh screws in here like the the Pcb and the pressure of the screws like that, and then um, the pressure on the back of the Lcd and then the case pushing down on the Lcd and that's all designed to put uh, adequate pressure on those uh, zebra strips. So yeah, don't worry about um, alignment on those, there's no problem and they can go either way. Up doesn't matter. So our culprit here is going to be the silver backing.

and somebody mentioned, oh yeah, it's probably been, uh, in harsh sunlight, which eventually, uh, degrades the you know, the silvered mirrored material. However, it is. they do it. So maybe, maybe, oh yeah.

Look, that's not that. that looks like it's going to come up in one one strip. Now if we take this off, of course we won't have the mirrored background so the looks going to be different. Oh wow.

I expected that to sort of like just shatter into little pieces. I didn't expect it to come off in one film like that, so I think I think we're pretty lucky. Look, check it out, we're pretty lucky And there it is. Oh there.

Yeah, yeah. there we go. It cracked. That's what I expected.

It actually cracked when we took that off. So now all I need is basically a replacement adhesive. uh, backing material. So like why it's failed like that.

If anyone knows the exact reason, uh, you know the like, chemistry reason behind, um, how that happens, then you know, please leave it in. the comments like you know, like it's almost as if like it's evenly leeched from the edges and then slowly like just leached its way in somehow. I don't know. You know? Look, hey yeah, I got no idea.

Maybe we could ask Mrs. Evie. Look, she's a chemist. What's what's left over here? Yeah, yeah, there's a bit of there's a bit of backing left on there.

What is that? Oh yeah. anyway. oh. you can also see maybe that that just needs a clean, but you can see those markings on the back as well.

and of course this will still work. I'll I'll actually put it back together right? I'll put it back together and show you that. this will actually still be fine. but you just won't get the really good contrast because you won't have that mirrored, uh, reflective in.

So the light passes through and then reflects off the mirrored backing. Basically, this is how a reflective Lcd works. So what's happening here? This looks like it's two layers. There's the reflective foil backing.

sort of like mirrored back in. And then what came off before? Ah, that. that's your polarizing material. So your polarizing materials just shattered.

And just yeah, that's what's actually shattered there. All that polarizing material. But it looks like the problem is not in the polarizing material. It looks like it's in that foil back in.

Or is there another layer of something in there? Yeah, you can see that there's another aspect to that film there that I've got to get off. sorry, bloody cameras in the way. I'll I'll have to do this off camera. I have to get out of the way.

now. I think that's just the adhesive between the polarizing film and the reflective backing. But yeah, as you can see, it looks like the the, uh, this has happened on, uh, the reflective backing. So yeah, it's it's not the polarizing film that's done.

It's definitely the reflective backing I believe. So you can actually see the segments inside there. That's the uh, liquid crystal itself that's all sealed like there's no way you're getting once the magic fluid escapes. Um, then yeah, you're not gonna.

It's not gonna work anymore. the active ingredient in all Lcds magic fluid. so I'll see like it's got all those marks on there from the uh thing. I'll see if I can wipe that off.

All right. Get an isopropyl wipe. Did that come off? I think it might have. Yeah, yeah, I think that's that's worked.

A treat. There you go. You can get the uh, there's my panels on the roof. There hasn't worked entirely, just needs a bit more elbow grease.

I think. Now this will, actually, um, still work without the reflective backing. Um, you just like it won't be very good. So I'll actually briefly put it back together and show you what it's like with no reflective backing.

End up Polarizer on the back, but we will see something there. You have it. It does actually work, but as you can see, it's not very good. Straight on is terrible mural, but you know if you tilt it like that, you can actually still get it to work.

But that's the importance of the reflective backing and that polarizing film that gives you that beautiful contrast. Let's try some alfoil, shall we? Not That aluminum rubbish. Genuine Aussie alfoil. So let's add some Elf oil in there, shall we and see how much that improves it.

It'll be a little bit crinkly. Yeah, you can see that. See the crinkle pattern in there, but I don't know that might add to the character. So put that back together and that's what keeps the this uh thing is designed to keep the pressure between the Lcd and the zebra strip.

Look at that, it's pretty how you're doing. There we go. That's what I talked about before about. If some of the segments don't make contact, then oh, I don't know.

There you go. That's what it looks like. It's better. It's better.

But uh yeah, we don't have the polarizing uh film in the back of it. so check that out. And of course, um, Lcds. I'll link in the video that I've done on how Lcds work because it's very interesting and uh, that's what happens if you just have the reflective backing and no polarizing film.

It's kind of like, you know, the outline of the sequel. It's kind of funky. I, I think that's kind of like it's it's not easy to read, but I like it. It actually looks kind of funky.

I kind of like it. Now if I put the screws back in, that's what it looks like. negative Meg items because that's my grubby fingers on the back of the Pcb. Um, that's it's.

kind of all right, isn't it? It's like it's weird. You're tilted on the side. Like at some angles the digits look solid like there right and then at other angles they look like they're uh, sort of. you know, like an outline with it, like in transparent in the middle.

So that's what the lack of the polarizing film at the back does because the liquid crystals are polarizing the light. so it's all part of the design. and that's how you get the great contrast. But yeah, that's if you just have the reflecting with no, uh, backside polarizer then yep, that's great.

And it's right. At this point that I remember, I'm pretty sure I've got another junked 20 series meter somewhere at the bunker in that multimeter box I talked about. So I I think I do actually have a replacement Lcd for this. Don't think about that the other day.

Anyway, we could actually, uh, you can buy some polarizing uh film of course. Although, um, yeah, we could try it. like I could, maybe scrap. I've got like a tub of Lcds here.

Maybe I've got one that has a, uh, you know, like the uh, the polarizing film at the back is hard. Like it's not like stuck on, um, a lot of them assembled without being like adhesive. Uh, stuck there. Maybe I can physically remove that and try and whack it in there.

It's got to be the right type. But uh yeah, I'll have a look through my uh, bin of Lcds. So to get this back looking good again, we're going to have to put that polarizer on the back and that's usually going to be a horizontal polarizer. and then there's also a polarizing film on the front and that'll usually be a vertical, uh, polarized film.

So um, yeah, it's not just enough to have that, uh, reflective back in. Otherwise, we've just got the single polarizer in there and we get that, yeah, weird sort of transparent effect. Anyway, Um yeah, watch my Lcd tutorial if you want to know how uh, these certain like the three different types of Lcd technology. This one, as I said, is a reflective type Lcd with oh, it's got a segment missing.

there aren't bad contact on the zebra strip. Anyway, uh yeah. as I said, this is a reflective Lcd, but there are three types and the other one is uh, transflective and that means that that pretty much say, does like half uh, reflection and then allows uh, the like, a backlight to come through um as well. And then then you've got a full transmissive uh type which has no reflective uh properties whatsoever.

and you can, um, do all these in various ways. And you can design Lcds so that you don't have black segments. you have like a black background with a like, a, you know, a white uh segment or whatever. So yeah, that's all to do with the uh type of Lcd and the type of filtering and the transmissive properties of those.

but this is a reflective one. and yeah, we need that rear polarizer. Unfortunately, I couldn't find anything really suitable in my kit of Lcds tub of Lcds, so I might have to go down the bunker and just, uh, do the cop out option and just try and find an old fluke 20, um, 70 series Lcd. All right, I'm down here in the bunker with a tub of old meters.

This is actually my, uh, not the boxes, not the two boxes of multimeters I've got. but uh, this is a box of just, I don't know, random old multimeters. and um, here is the first. Oh geez, the color balance in here sucks.

Um, here is the first digital meter that I ever owned. The saw me five double three. I'm sure I've done a video on that. Um, I did not buy this one because I couldn't afford a digital multimeter back then.

it was actually given to me, um, by my cousin who was into, uh, repairing, uh, pinball machine like you know, arcade machines and um, there's stuff like that. Didn't really know him, uh well. but anyway, he, um, this was surplus to requirements. uh to him and I thought this was the absolute ducks guards.

I was, maybe you know I was like 10 at the time or something like that. You know, 10 as something like that. I just had a my analog meter of course and um, so anyway, so that's that's my first ever digital multimeter. I believe it still works.

So anyway, I was very disappointed. I was devastated when uh, fluke came out. I just tweeted this the other day actually fluke and I'll see if I can put the ad up here. Fluke actually came up and they posted this ad which um like how to beat the high cost of cheap meters And there was this meter.

I think it was like the upgraded model with an extra button or something and it had extra current range or something. And it was, um yeah and it was just like beat up held together with gaffer tape or something. in the background. there's this shiny new fluke in the foreground.

So yeah, I was, um, absolutely devastated when I saw that because I thought it was the dark scars. Anyway, um yeah, these are probably like old mailbag meters, but ta-da here we go. A Fluke 70 series. This would have been.

I'm sure this would have been the one that I blew the arse out of, wouldn't it? Um, so yeah, I'm going to. uh, I'm going to take that back. and um, I think the Lcd looks still even got still, even got the protective film on it. Jeez.

Anyway, so I'm going to take that back and that will work. A treat winnowing a chicken dinner. And here it is. Anyone remember that video with Doug Ford and his uh what was it 40 jewel or was it 400 dual? um Destroyer? um of meters and uh yeah, that was a famous old video that I had.

Um, I think yeah, I don't know. Did it go viral at the No? Well, went viral for like 11 years ago? Anyway, um and yeah, people love that where I blew up a meter and I believe this was the one that I blew up. The knob actually blew off. um, from it.

So yeah, it's somehow reattached, but uh, if I remember, uh, rightly yeah, it's um, just the um, like the input mobs or something blue and probably the fusible resistor as well. Oh, I've got feet. I can, I can use those, but let's crack this sucker open. Got myself some new screws too I can use and I could probably reuse the bottom half of this case too.

Um, with the threaded um studs that I had. I like it should be. Although this is a series two, this is a series two, but I don't believe there's any fear. I don't think there's any physical differences.

Can't reuse the entire case because uh, then you know we don't have the um, the amps jacks over here because this one doesn't measure current but still got ourselves some new screws. New bottom half case make it into a Franken monster. So let's take it open up. Yeah, uh yeah, yeah.

I think the uh, I think that there's a bit of a bit of charring around the mobs down there, and uh, the input resistor looks fine, so that's all right. let's take it out. Hello. Oh what, somebody's bodged it That was not me.

that was not me. I have to re-watch the previous video. Um, somebody's bodged that this has had. This had a failed input protection resistor just like the, uh, fusible 1k resistor.

Just like uh, we had in the previous video and someone bodged it. they didn't have a replacement. They bodged it. That's what happens when you bodge it with the quarter watt jobby that I did in the previous one just to get it working again.

Um, so that would be interesting if I replace that to uh, say oh yeah, Trace has come off. There we go. My guts are. but yeah, it'd be interesting to know if that still works.

I'll look now. now. we've got the surface mount tents now. Um, so yeah, that's the that's the Mark Ii job.

Um, series two job. Anyway, Oh yeah, we can get the Lcd out of that more Ernie Bernie Marks. Another interesting difference between the Series one and Series two is that, uh, the series one has, uh, the silk screen printed on the outside like this, whereas the Series two has a silk screen print on the inside. I guess they learned that, uh, you know this was even though it's yeah, it's on the it's on the inside There I did.

Well, that'd still be very well protected, but I don't know. They determined that, uh, when they upgraded this that I don't know, it was easier, better, whatever to, um, put it on the Lcd itself. So there you go. Um, yeah.

so I can't just swap out the Lcd module because then I'd have fluke 70 Series 2 underneath that and that would kind of suck. But anyway. and so yeah, I'll have to physically remove the Lcd itself. For those curious to know.

Yes, uh, they haven't gone to gold Plated yet. Still, that tin plate? rubbish. It looks like they haven't changed the plastics there at all either. so we'll just extract that from there and we'll get this one out of here.

It's going to be a little bit stuck after all these years. Yeah, it's stuck on the zebra strips so we'll keep keep everything original, shall we? So we'll put those back in there like that. Then we'll transplant up. Don't need my, uh, dodgy back in anymore, Transplant that over and that will work.

a treat so we'll work that back on there. Oh, I cracked it. Damn it. What the? Oh yeah, I was slightly off.

I cracked it. Ah, Kamikaze. Hopefully that shouldn't matter on the pressure. Oh idiot.

There you go. Winner winner chicken dinner. Yeah, great. But now I'm thinking uh, like this is a series two meter.

like you could actually populate this with the jacks. You could. Actually, I didn't. I know.

Yeah, I'm not gonna do it for this video. but anyway, I will actually power this up. um to see if it still works, but it has at the snot. Absolutely.

Oh yeah. look, oh boy. hello, oh wow. Looks more like it's chipped away rather than it's night night.

No, it's blowing away. It's had the it's not blowing out of it but so I don't know if you technically, um, it's a it's the same Pcb uh, and the same, presumably the same chipset. It'd only be a jumper link that sets the uh functionality of it. Yeah, you know you might be able to turn that into a fluke 77.

maybe. You know, if you put in all the protection, uh, parts, the fuses, and uh, whatnot. and um, yeah, in theory. Anyway, so the million dollar question is, are these back cases compatible? I think they look pretty done compatible.

To me. They have changed slightly. how that, uh, condom, the, um, the shielding? uh, tape now? um, contacts directly. It doesn't have the spring anymore.

But um, yeah, I mean, that looks good. I think they've used exactly the same mold. Oh no, no, sorry, no, they've got the extra blast shield in there. Oh, that's interesting that's not going to fit anymore.

No, oh no. I could shave that off. If you were really desperate, you could shave that off. So yeah, the new Pcb has the um, the shield there, um, separating the volts and the uh, and the protection stuff just for some extra clearance there.

So yeah, that's that's very nice. So they upgraded that uh design a little bit. uh to go from like the previous little tiny slot here that they had. Um, but that was it.

So yeah, we'll have to stick with the stick of the previous one. But there you have it, that is now a working Fluke 23 multimeter with replacement Lcd when you win a chicken dinner. But I got a bonus holster for it. Ouch Ouch.

Ernie Bernie, I had to turn this on quickly. I like I was touching the back of this. um, and it doesn't come on like you probably might have seen that And I was just putting my finger on the back and I burped myself. probably through that resistor.

There was, um, heating up. I was just, you know, handling the thing and um, the energy from the 9-volt battery is going through there. So yeah, this is one sick puppy. Um, yeah, that might have to be another.

It must have been that because I it must have been that resistor there bodged on the back that the 9-volt battery was just causing it to do that. Um, so yeah, I turned it on and I had my hand on the back and all of a sudden. yeah, Ernie Bernie, so that's interesting. Yeah, that one's uh, one sick puppy.

but the Lcd comes on everything so the processor might still be good. Yeah, could potentially repair this thing because I'm gonna snip that out of there, right? I'm going to get that out. and let's see. and uh, well, yeah, I guess I can measure it.

Oh geez, why not? look? you might. But it's going to be open. Yep, yep, it's open, right? So let's plug the battery back in, see if it, see if it burns me again. No, there you go.

It's just. nope. Nope. Nothing's getting hot.

So it's um, yeah, like it's it's on. So obviously there is, um, some way, like for that Lcd to come on. the processor has to work. There's the boot up delay, there's the turn on delay, and then it comes on.

So to me, that indicates that the processor works. but it's not. Well, at least it's well. no.

I guess the Lcd driver works. I guess maybe that's just it. But um, yeah. Anyway, that's one sick puppy that was interesting.

I didn't expect to get burnt for a blunty nine-volt battery, but you know there's a decent amount of uh energy in these puppies and they can can deliver a reasonable, uh, amount of, uh, power. It's not great. There's only there are only uh, six, four a cells in there. but still, you know you hook that up to a low enough value resistor and yeah, it's it's going to heat up.

Catch you next time you.