And it's junk Bin time again. And yes, you guessed it, it's another monitor. another non-w working one. I Found this one.

uh, inside a box for a new monitor I Saw the empty box there and I thought I wonder if there's anything in it? Sure enough, there's the old monitor they were replacing in this, uh instance, it's an LG Life's good. Yeah, they changed it and it's a flatron W1 1942 T 9 in it's wide screens. you know it's It's not that great, but it's certainly worth salvaging. And I have tried to power it up and uh, it gave a an image briefly for a couple of seconds and then it's just kaput.

So what do you bet? it's the Caps Let's crack it open and it's another one of these pain in the ass clip ones. Really don't like them. much prefer the uh, good oldfashioned screw, but what can you do I wonder who actually makes these design decisions to go? They're going to, uh, make this case clip instead of screw I mean I know you do save a couple of cents, but jeez, you know, really tight asses. we're in like Flynn Woohoo there we go.

Hey, there we go. This one's a bit different construction of the other one. the uh, flat panel comes out of the top and the boards are on the bottom. so let's disconnect the ribbon here.

We got our back light over here and this LG monitor is pretty darn ordinary compared to the Samsung one we looked at last time. It's not a full metal shield. uh, shazzy at all. It just sits in this little metal frame here, which is, you know, okay, in its own right.

Um, but it's certainly nowhere near the quality of the uh Samsung monitor we saw last time in terms of physical uh, build construction. and the board doesn't look nearly as good a quality. And once again, of course they got a single-sided PCB PA of the course here. But look at these dodes here.

Just pushed in. dodgy at any old bloody angle? Horrible, horrible. They've got a little kink in them. uh, to stop them going all the way through? I Mean they've done that.

They mounted them off like that to uh, uh, give them, uh, spacing and some heat sinking with the extra leads. and to get them off the board and you can actually see on there. You can actually see a heat sink symbol, so it's almost as if, well, they were supposed to mount these on heat sinks and you see the footprint in there for like a vertical To220 package device. And they've gone a buger that we won't use.

an expensive To2 220 package. Diod and a heat sink cost a fortune. We'll save some scents and we'll just whack in these ones here and just leave them free standing off the board. Oh poor form Really? H Just terrible.

and uh yeah, they're just pushed in there at any old angle in the factory. not in China in this case in Indonesia up the top here is an M205 size. uh Direct solded in fuse like that. Don't particularly like that, but hey, at least it is fused right and and they've got, you know, basic, adequate protection and um, some filter in here.

But yeah, they haven't really gone to town on the input side of stuff. They've got uh uh, Shake proof washers on the earth lug down in there, so it's it's okay, you know it's it's not too bad. I guess it's passable I Guess you could say and uh, what we're really interested in though, are these caps H Well, well, well, what do we have here? Check out that little sucker. You can see the Bulge in there clear uh, case of these things dried out and this one here as well completely dried out 1,000 M Cap 105 C rated uh Samir brand Swh.

In this case, we haven't got caps on like we got last time. It looks like there's only bugers in two of them. The other ones look reasonably okay, and the main DC input filter capacitor here looks okay too. No bulges in that.

These ones get uh, uh, less stress usually than the output caps. 450 volt rate at 105 C And once again, it is Samir brand WL series. And the ones that have clearly failed here are also WL series and Samir aren't that bad a brand of capacitor and the WL series isn't that bad either. So I think it's just probably either these things got too hot, um, and or the age of the things and they've just slowly dried out and well, you know it eventually happens to these caps.

So um, let's take so I'm definitely going to have to replace those two that are bulging. But what about the other ones? I Think it's time for the ESR meter. We didn't look at that one last time. Now the correct tool for the job here is not.

And I repeat Not a capacitance meter. What you need is an ESR meter or an equivalent series resistance meter. These are specifically designed to measure the ESR of a capacitor because the internal resistance of these capacitors is what uh actually determines their performance in these switch mode. Power supplies needs to be really low and when they heat up, the um, uh, dialectric material in there actually uh, dries out and the ESR increases, the capacitance might still read fine, but the ESR is the thing that goes through the roof with these bad caps.

Now what I've got here is the famous Bob Parker designed ESR meter. His name is Bob Parker he's an Australian and he got this originally published in Electronics Australia magazine, but this is the updated Mark 2 version from Silicon chip and ESR meters are all the same. What they do is they pass the key to it is passing a high frequency 100 khz test signal through the capacitor Because if you look at data sheets for virtually all these electrolytic capacitors, the ESR the equivalent series resistance is specified at a frequency of 100 khz and that's exactly what this ESR meter will put out. and it'll also put out a low enough voltage so that it doesn't turn on any semiconductor Junctions in the circuit.

So these are not only can measure ESR, but they can do it in circuit I Don't have to desolder these capacitors in order to measure them, and that's a brilliant thing about one of these ESR meters if you're into repairing stuff. Pretty much a musthave unit now. Uh, we've got these five output uh caps here. Only two of them are showing bulges.

So let's uh, switch this sucker on here and we need to zero it out. There We go. We've zeroed out our test leads here and it does have a table of typical figures on here, but you know that's only really rough. Rule of thumb.

Like what are we talking, these caps are 1,000 Well, 470 mik? Uh yeah. 470 mic at 35 Vols So you know I'm not really going to go by that. 470 mic at 35 vol.1 100 milliohms? So .1 on here. Eh, it should should be lower than that.

Let's go check the data sheet and sure enough, I checked the data sheets for these WL Uh series Samir caps and uh, the value is um 0.027 or 27 milliohms maximum. um at 20 Uh C for these particular caps 470 Microfarad 35 Vol So let's uh, measure them here and see what we get. So let's measure a good one here. The these two a good one.

So let's flip this puppy over. We've zeroed our meter here and we're looking for something under that 027 Mark There we go. 0.01 Not a problem. 02 You know it doesn't have the resolution really to go that low.

but ballpark, that cap is just fine. So really, uh, there is no reason to change that unless you really want extra long life. I mean this one. These This one might eventually fail as well, but at the moment to get this thing back up operational again, we don't need to change that cap.

It's just fine. Now this one next to it here. and by the way, make sure warns you on here discharge capacitor before measuring. You don't want to blow the ass out of your ESR meter.

So this is another one which is not bulging and there we go. 0.02 Ohms 20 Milli Ohms that one's fine I wouldn't bother changing that one now. this one here. This one here is a bulgy and so is this one.

I Can feel it and you can see it. We're seeing the close-ups on that. So these two, well, let's measure this third one over here which isn't bulging. So let's do this one and we've got .02 Again, that one is fine.

wouldn't bother replacing that. But first Bulgy One, Let's take a look. There's the two pins there. and the great thing about this is you can actually measure the in circuit and cuz it's a low enough voltage, it's not going to switch anything else on this capacitor.

These large value capacitors will be by far the lowest impedance device in this whole circuit parallel across that voltage output rail. So really, it basically essentially ignores everything else. So let's have a look at it. Hey, there we go24 240 milliom.

An order of magnitude higher than what is than what the spec for that capacitor is. So it's clearly failed. So even if it didn't have a bulge in it, a bulge is the usual giveaway, but it doesn't always have to have a bulge in it. So the standard practice would be to go around measure all the caps in a product like this and see which ones are out of spec.

And here we go next: bulgy one. But I found that most of the time they they do bulge. When they do fail, they do bulge. and oh, look at that one.

That's a shocker. 61 Ohms. And by the way, no, the polarity doesn't matter a rat's ass. With these things, it doesn't matter at all.

Um, electrolytic capacitors are polarity sensitive, but because this is such a low voltage, it doesn't matter. You're not going to harm any good capacitors by doing that. So there you go. Bingo with these two culprits.

I need to replace those. They're Gonsky. There's a little one down here hasn't bulged I might actually measure him as well just for good measure. but I don't He's not a big output DC Rail cap.

so I'm not I'm not too fussed on that .14 It sounds about right for a cap of that that size. So yeah, good enough. need to replace two caps there. There you go.

Check out the Uh. Check out the Charing there under underneath the Um backlight. uh Transformer there. it's been getting a little bit hot that one.

and uh, here's the base of the board. nothing special. It looks a bit looks a bit groy, not not that impressed. It's not as good as the Samsung one we we looked at anyway, but yeah, they're kind of doing the right things on there.

And for those curious, I will measure the big Um high voltage cap over here. Yes! I Have checked, there's no voltage on that. it is discharging. Usually they'll have a bleed resistor across it, but always measure it before you do that one.

This is only 68 microfarads at 450. Vols so let's flip it open. where is it there? over? That's that one. and that one.

0.8 Ohms, That sounds pretty decent. I Mean if you go by the Uh chart here, it doesn't go up to 450 volts. but you know 68 it? you know, I expect it under an OHM and that's what I'm getting. So really I don't think that one is a drama at all.

And just to clarify that, we do actually have a mix of WB series and WL Series. So the two that are failed of the WL series these 470 mics um uh, WB series. they're all fine. But the two that failed here they are the W L series at 1,000 mic and the best I've got are these J car SI brand th000 mik 25 Vol instead of th000 mik 16 volt.

Once again, you can go up in voltage. no drama at all and you can go up in capacitance. No drama at all. but uh, do not go down in voltage.

That's a big noo. and don't go up uh sorry. Don't go down incapacitance either. You maybe get away with going down a little bit in general.

you, uh, don't really want to do that. so let's just whip these out here. All you got to do is heat up one pin and pull out one side and then heat up the other one. What? I got my IR set to here.

not that great so that pops out. And of course we can't stick our capacitor through that hole there unless we've actually got a hole. So we just whx some solder Wick over that and put it down and bingo it Wicks the solder away and Tada we have a hole. and we do the same thing here.

Got to have solder Wick It's absolutely essential and that should Wick that away Bingo And we're ready to whack in our new caps. Make sure you get the polarity correct and there's the uh, their low ESR type. Of course you must use low ESR types for these switching power supplies. Crappy SI brand I know, but it's all I've got.

They are 105 C rated so let's stick those in and solder them and see if we can fix this sucker. And just to prove that that fixed it, let's measure our Sr again. There we go: 0.03 Not as good as the other ones, but near enough. There we go: 005 Good enough for Australia That'll get us out of trouble.

that'll at least get this monitor up and working. Let's give it a try. So here we go. let's give it a try.

I haven't snapped the bezel back on yet I'll just, uh, hold off until we get the AOK Tada Hey, we have a blue light. We have a blue light and I saw the LG thing there TDA check signal cable and bingo there there it is for gone. Conclusion: It works. An absolute treat.

Perfect. Another win for dumpster diving I Love it. Catch you next time.