Hi If you saw my dumpster diving video, you know that I scored two of these Samsung synm 204b monitors with the nice um T portrait uh, tilting stand on them. excellent uh and I assume they would work cuz I have got monitors from down there before that have worked. No problems at all, but unfortunately these uh two don't look like they work at all. the light doesn't come on.

I've tried to hook them up to a PC nothing. Usually you should get some sort of menu or something like that so it looks like these things are Cactus And of course in all these sort of uh things, well, pretty much uh, most Electronics uh, gear like consumers and computers and um, you know, set toop boxes and all sorts of things I think I've done a video on that before. One of the most common culprits of course is the electrolytic capacitors in them. They fail bad and I had a whole bunch of comments on my dumpster diving video that uh, these Samsung SN Masters are notorious for bad for having bad quality caps in them.

So I thought we'd uh, open it up and uh, try and replace the caps in it and see if it fixes the problem. Well check them out first and uh, see if that's the issue. probably I reckon with about 90% 95% certainty maybe um, it will be the caps in the power supply because Electronics is pretty reliable. Uh, just regular um, active and passive components.

Very reliable reliable. But electrolytic capacitors of course have a dialectric liquid in there that can actually dry out with use. And when they get hot and these things get reasonably hot inside. and I've done videos on this before, so almost certainly it's got to be the Caps let's crack it open and I can't see any screws on this thing I think it's a plastic retaining Clips around the edge.

What a bastard. Ah, spudger time. Well, that was pretty annoying and now you got to. it.

just looks like it just lifts out now. I would have preferred screws. hate those plastic retaining. Clips we' got a there we go back panel just lifts off real easy.

This thing is quite heavy. It's uh, really well shielded. As you can see, it's uh, bril built like the proverbial brick Ouse. I like it.

and it looks like this front panel connector just comes off the switch, front panel switches and bingo we have our scre green. We can now open this sucker up. We should only have to get into this uh, top access uh panel here and uh, that should give us access to the power supply circuitry under there I've lost my good Phillips screwdriver unfortunately. so I'm going back to the old one I've had since I was a kid I uh, had that since before I even turned 10 I think that's how long I've had that screw SC driver.

So let's have a look. Two screws there. doesn't sound right. what's going on here that's all integrated with this.

It's folded. This is all folded over the top and integrates with. Ah, it's rather annoying. Uh, ah.

There we go. All right. Couple of screws on the side and then this whole top bracket should just lift off. There we go.

Yep. Beautiful. And as you can see, there's not much to this thing. just the two main boards here.

And instantly I mean all we care about is the power supply one over here. I mean we've got some, uh, backlight inverter stuff here. This is the Main's power supply section. Andy We've got it straight away and look.

they're dodgy. Caps on Brand: Can you believe that? Samsung use uh caps on that one actually looks okay. There's no bulge in it. but these are also caps on uh brand up here which I'll give you a look at and these are dodgy.

Look you can I don't even have to measure those. You can see the bulges in them. And the choice of those caps is. uh, quite surprising because this is an otherwise very nicely engineered and laid out.

Uh, you know. Uh, Main's switch mode Power supp Supply They're doing all the right things here, except for the choice of caps. It's actually very nicely laid out and they're doing all the right stuff here. They've got, uh, trans orbs? they've got themister, they're uh, celastic in those over so that they don't vibrate loose.

The main uh DC input filter cap is celastic down. Ah, it's all happening. They've even got the dip marker to show how it, uh, which direction the board flows through the dip. um.

soldering machine. you know, the wave soldering machine. and ah, lovely. And here we go.

We have some caps on Uh 25v 330 Microfarad. You can see the Bulge in the top of the cap near the vent hole there, and that's a dead giveaway that there's been pressure build up inside there. Which means that all the Um electrolyte fluid has dried up and of course, course, this one has actually vented out. Check it out, That's an 820 Microfarad, that's you.

don't see 820 Microfarad? uh, too much these days. Um, you know, usually it' be like an even thousand. Um. But there you go.

Um, 820 Microfarad 25 volt caps on absolute classic case of electrolytic capacitor rupture. There, it's gone bad. I don't even need to get out my Bob Parker ESR Meer and measure those I know they're gone bad. Anytime you see a bulge in an electrolytic capacitor like that, you know it's gone and you got to replace it.

And we've also got some caps on Uh 330 Mic 25 volt ones on this side here and that one has a slight bulge un it too. the one behind it seems to be okay, but as a matter of course I'm going to replace all of these caps on brand caps now. I'm not sure if I'm actually going To replace that uh main DC input filter cap the Main's input filter that's 100 microfarad 450 volt cuz I can't see any signs of bulging in that at all but it is a Capson brand so it instantly um uh, you know brings into question even if I didn't know what brand it was. if you see that the same brand are all leaking and bulging over here, you got to assume that uh, you're going to have a s similar problem with this one but I reckon I can probably fix this thing by just replacing the DC output caps cuz these are the main output caps on the main DC rails which power all of your electronics here.

and of course if they're no good, if the uh, all of the electrolyte fluid in there is, uh, dried up all the pressures built up in there, then of course you're uh not going to get a nice smooth DC rail to power your electronics. you're going to get tons of Ripple on there and all your digital electronics is just going to play Silly buggers and not going to work work at all. So yeah, I don't know whether it depends on uh, how much they cost and whether or not I can get them from Jart now cuz I want to fix this one like now in the next hour so or both of these monitors so I reckon I could probably get away with not replacing that one. It's not great for the longterm, but anyway, for the short-term fix I reckon uh, just the output ones.

And if you're interested in seeing the main board here, it is. um, it's got a date code on there of Uh two 2007 by the looks of it, but it's pretty much just a single chip. um, solution. As you'd expect these days, you know, here's your uh input connector, your DVI and your VGA it's all in one chip.

Geez. I can remember monitors I can remember uh working on Um flat screen monitor designs back in 1994 I think it was about 94 is and to do what they're doing inside this? Mona even at lower resolutions like 800 by 600 at the time, this is before our widescreen really kicked in. Um was hideously complex and it required a, you know, a board full of chips just to digitize the Uh VGA input and convert it to flat screen. Now it's just one little Qfp package, thank you very much.

And you can see the RF uh Ferite bead there for Um Emi uh suppression. So uh, that will knock some of the edge off those digital signals. high-speed digital signals flowing through that parallel data link there. And of course, there are some surface mount electrolytic caps on this logic board.

But really, you know I don't think they're going to be a problem at all. It's definitely the ones on the main power supply board and you can see on the back of the board here they've got some uh, insulation actually very nicely um clipped into the main board. I Really like that? um Samsung Have really gone to quite a bit bit of effort to design this thing properly, which is all the more disappointing. Why they're using crap quality caps in this thing.

Check out the bottom of the board here with its uh, nice sexy black solder mask on green. It really does look very nice. I Really like it. They've uh engineered this thing quite well.

as I said, look at the uh high voltage isolation slots they've routed into all this stuff. they H someone's put a bit of Pride into this uh layout. Let me tell you, it's beautiful and we've talked about this before in other videos. You can see the selective Um removal of the solder mask on those traces as they thin down.

You see how they're fatter here and they thin down here and just to increase the current capability of those traces just a tad. and they've done the same thing down here on the main. this is the Main's input switch here, the I connector with the Uh main switch and they've done same thing there. So after a quick trip to Jcar I picked up some dubious brand low ESR capacitors here I Say that because uh jar don't exactly have a stellar reputation for supplying primes.

speec Quality Parts It's like whatever they can get really and these are SI brand. Never heard of them I don't know. don't trust them as far as I can throw them. but the only choice had if I wanted to do this properly I would have um gone to Fels much further or ordered them I can't wait I wanted to fix it within the hour.

So these are the best that I could do. um, 470 microfarad 25 volt replacing the 330 microfarads. If you're going to replace these, uh, don't go down in capacitance value. if anything, go up.

They didn't have any 330s. Um, so I'm using 470 25 volt. They're a bit physically bigger, but they are 105 C uh rated? That's what you want. Uh, because the life of capacitors um, drops with an increase in temperature and if you've only got 85 C-rated ones, they're not really good enough.

Um, and it's a low ESR type. That's what you want with switch mode power supplies like these. You don't want regular capacitors low ESR Trust me, that's the business. So I picked up that and I picked up a uh once again SI brand th000 mik 25 volt Uh, once again, low ESR physically quite a bit larger I think it's the same uh pin pitch here.

Um, but hey, Beggars can't be choosers. it's all they had. Um, you know if I went to F Els Yeah, I could have picked up. Um, just exactly the right uh, cap that I wanted in the slim profile and you know, a quality reputable uh brand Source from the you know, the no one, um, reputable Supply But anyway, we'll throw these in.

it'll get it up and running. Um, as long as they physically fit, let's give it a go. So there you have it. I've replaced five caps here.

these ones. um, as you can see, they weren't physically the same. uh, diameter. They're a little bit, uh, uh, wider in the diameter so they don't quite fit in there that well.

But anyway. uh, good enough. it's going to work I Um, didn't uh bother to replace the Uh Main's input? uh cap. cuz they were like 750 each at JC Car Screw that, but these ones only cost me, you know, a dollar or two total.

So hopefully, um, that will get us up and running. All right. let's power this thing up and see if she works here. We go.

Hey, the LED You probably can't see that, but the LED is consistently on and it's working. look Tar: analog, digital. No problem does menu work. So there it is.

Check signal cable that is working a treat. I'll put the Uh front panel, clip that back on and uh, no worries. I'm sure if we hook that up to the Uh VGA um output of the notebook or the DVI output, it'll work a treat. Beauty And here's inside the second identical monitor.

the main input uh filter cap looks fine once again, the same caps on Uh brand. These ones look okay, but I'm going to change them as a matter of course. And there we have the bugies. and there they are and the second monitor I've replaced all the caps in there, lights coming on and and bingo there it is fixed as well.

No worries whatsoever. H And there it is. Works perfectly. both of them.

So there you have it. Two repaired. Samsung Synm 204b 20in monitors I Got from the dumpster. good old dumpster diving.

Fantastic. Fixed with a 10 minutes work and a couple of bucks worth of caps. and these are excellent monitors. Beauty And there's probably some poor design engineer at Samsung right now just doing a big face palm because they designed and uh built this thing beautifully only to have some in the purchasing department purchase dodgy caps instead of probably the Panasonic ones they specified in the bill.

materials. You know, purchasing? just. oh man, we'll get the cheapest caps we can. We're going to make a million of these monitors.

Oh look, I save the company, you know, 50,000 bucks in capacitors Beauty not and just remember when you're fixing uh, bad caps like this to replace them with good quality low ESR types. The low ESR is important because it's the high ESR that uh causes the internal Heating and then the pressure buildup and the uh drying up of the electrolyte inside the capacitor that causes all these problems in the first place. So they're a bit self-perpetuating in that respect. If they start out you know, a little bit dodgy, then uh, they're going to heat up a little bit inside.

that extra heating uh increases the temperature inside the cap, increases the ESR equivalent series resistance, which then increases the heat even more, dries out more of the electrolyte and so on, and so on. and it just snowballs until it just music, guts, and uh, stops working at all like we saw in these monitors. and lots of stuff. Uh, lots of consumer items uh PCS and set top boxes and DVD players and TVs a lot of them will be an easy fix like this by just changing the caps in them.

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