Hi welcome to Tear Down Tuesday or today, more accurately, Dumpster Diving Tear Down Repair Tuesday Cuz look what? I scored in the Eev blog Junk Room Another dumpster diving find Brilliant It's a Yamaha RX V57 surround sound receiver. It's not new, it's You know it's reasonably old and it doesn't work. but I think it's worth cracking this s open, see what's inside, see if can fix it cuz it's a pretty good general purpose receiver. They even thoughtfully included the remote control I Love it! Thoughtful dumpsters and they even included not the original box, but the box for the new one.

Here it is because, uh, they've clearly, uh, got. You know this thing's clearly failed and they've uh, purchased this new one and they thought, well, we'll just dump it in the new box with the remote. They even included the Am loop antenna as well, so this could be interesting. Definitely worth fixing.

I Think this is quite a score. Yeah, you can probably pick them up reasonably cheap on eBay in working condition, but this one is free. Woohoo! And here's the receiver. and as I said, it's uh, not a new model.

it's maybe five or 6 years old or something like that. It's the Rx- V57 and it's you know it's got Dolby DPS it's you know, 6.1 Channel or the usual surround sound paraphernalia. but it is Yamaha's Rx series which I believe is like their you know higher end, uh, you know, consumer Series so it's a pretty good one for its age and as I said, it doesn't seem to work it. uh I've got my energy meter here and um, it's saying it is drawing a standby power of about .12 watts and the uh, and that's what it says in the manual manual says about 0.1 Watts or they about standby so clearly like it's not the fuse in it that's gone or anything like that.

It's something to do with this soft switch power button. so uh, it should be interesting. Now you know The first thought might be oh yeah, it's a blowing cap or something like that. um possibly as we've seen in previous videos, but uh I don't know it.

uh, could certainly be something else to do with the soft power on standby or maybe something horribles happened to it. We have to open the thing up and uh, really have a look inside but this should have I would expect uh a Yamaha let alone their RX series to have premium brand caps in here. you know they will have uh, you know Panasonic nichon or something in there. Um, you know.

So I It should be a pretty good construction inside, but only one way to find out. Let's uh, crack it open I've got it on the uh I've got it on my little turntable here I Love my turntable. I Can just this thing weighs a ton and I can just spin it like it's nothing and uh, it does have all the requisite uh inputs. Of course you know it's got like all the uh, digital, um, it's got all the optical, uh fiber inputs.

It's got uh, component, a bunch of component, or a couple of component videos. It's got uh, video upscaling, it's got standard composite and S video and uh, it's about 90 wats per Channel I think um, at like a point 05% Distortion or something so or 09 or something. So it's actually a pretty good um amplifier in its own right. And this thing actually contains a ton of uh, great components in here.

or they'll be mostly through hole or serviceable stuff like that. So um, people throw away these things willy-nilly these days when they fail and you can pick them up on eBay These surround sound receivers quite, uh, cheaply. And they contain a gold mine of uh, well, if you buy a quality brand one, they're going to contain a gold mine of quality brand component. So well worth salvaging.

And it's got like a control output here plus 12v control. It's got external remote inputs in. this is going to be good that it's got it looks like a switched AC outlet as well. So let's crack this sucker open and uh, see what's wrong with it.

Now it's a little bit Dusty on the top here and uh, but it looks I can see down through the grill in there and it looks pretty uh, pretty clean inside. So I think we're going to have um I don't There doesn't look to be anything horribly wrong. inside. there's no visible anything visibly exploded.

Give it the sniff test. Nothing. uh, nothing seems to have burnt out or anything like that. So I expect um I Expect it to be something a little bit more subtle than that.

so nothing. I don't think anything's gone horribly. Boom in it? Uh, that's for sure. and it looks like it's been kept in pretty good.

Nick There doesn't look to be any dust inside, just a little bit of dust on the top. But really? I think it's been kept in very good nick. I Can see a huge Yamaha Transformer in there. so Yamaha are a quality brand so you'd expect to see this Very well built, very well constructed.

I'm not sure what it originally cost I don't think it's that like it's not their top of the line model or anything like that. but um, it certainly is not a one hung low cheepy. Let's put it that way. So I think we've got it all now, so let's crack this sucker open and Tada there it is and check it out.

Inside, it looks very nicely constructed. Check out the monster. Yamaha Transformer Here that's an absolute beast and uh, two huge caps in there. We'll take a look at those for the main rail.

uh, massive heat sink here. We'll have our bunch of mosfets along the bottom board. This top board doesn't look to be, uh, like it's the amplifier board. looks like the bottom one is and uh, lots of flat Flex ribbon cables running around the place on this, but uh basically.

um these things. as with very typical with consumer um items like this, they're all through hole. uh yeah. Well they're a mix of like surface mount so they'll have like you know, a surface mount chip like that.

They'll have surface mount parts on the back up here we can see but the boards will all be single sided and they'll contain all huge numbers of links like this so well I'll take I'll give you a better look at the individual Uh boards. I may or may not tear this down completely. so this is going to be more of a a repair video. I Think that an actual tear down video but you can see they've got Uh cards up under there so if we have a look at that, probably can't see that in there.

But there's a whole bunch of cards for all the various Uh inputs along here. so they got a card for each different thing and it looks like they are all I Know there's one double-sided board. This one here is a double-sided board but these are all singles sided with uh links going everywhere and our problem could be over here cuz here's our Main's input of course I've got it. Yes it is disconnected by the way.

but um, just be careful with these because these caps can hold a huge uh charge on them by the way. so just be careful if you are poking around inside these things. But that is going to be our first portter over here. Uh, that is our Main's input board which looks like it has a standby uh switch mode uh power supply fly in it cuz this is clearly a big linear Transformer here that powers the actual amp and they disconnect that I can see a relay down in there actually which we'll take a look at which clearly disconnects the main Transformer So they've got I presume they're going to have a secondary uh switch mode converter on there very low power 0.1 wats which powers that soft front power button.

Let's have a look at this uh top board here which is not the power um so it sort of contains miscellaneous stuff Tada There we go. Quality brand caps nichon they are uh, one of the best in the business and if we take a look at the main filter caps down here, they're are Nichicon again Kg series 85 C but it looks like they're like they've got some uh writing on there. Very hard to get in here and see it but it says like gold series or something like that hence the uh hence all the gold on them. So I detect a sense of audio Foolery going on here.

these are audio in quote marks class capacitors I Think so let's have a quick look at the data sheet for these suckers and see if there's any wank words in there. Yep, here you go folks. I was right on the money. nichon uh designed for high-grade audio equipment giving priority to High Fidelity sound quality Yeah, right.

Dry that one out. you can fertilize the lawn folks. um, the uh variation expansion of the Kg series. We've got a bit of Chinglish happening here or jingl um because I believe nichon are Japanese capacitors.

So the low profile High tone quality grade of the new development electrolyte adoption Woohoo! The center grade that the best sound is provided electrode foil with multiple use type three the highest tone quality grade by the low drag the gold pla in terminal adoption. So they've got three Uh grades of uh so gold tone so there. super through through to oh gold tune through up to the higher grade super through I guess I Assume that we have the gold tune one here because we have the uh gold, um sort of colored stuff I guess But yeah, there you go. There's a a bit of audio Foolery happening here.

but um, you know these are top quality. uh caps, these are. you know, bet your bottom dollar these are top quality stuff. So um, you know.

Although they've got this audio uh Foolery stuff in here, the wank words: these are really top grade caps they're using in here Thumbs up! Now we have a look at that uh Mains board in more detail in a minute. but uh, you can see that there's a relay on there, there's a little Reay there's another Reay down there and uh, nice looking heat sink down in there and that is the main powerboard. Don't you just love those huge uh, sort of like bus barar links in there massive links. This is a single-sided board.

They've put those huge links in there I Do love the uh look of and the design of these of single-sided boards inside these, uh uh, bits of um, you know, sort of higher end consumer grade gear. It really is quite nice and it looks like the Caps they're all Nichon brand, even the small ones down in there. so they I think they, uh, they haven't skimped at all. And as for this board up the top here.

I'm not sure what this one actually is, it seems to tie together a whole bunch of others, but they've got a surface mount chip there with uh, check out those little sort of almost like heat sink uh tabs on the side of them and I love the silk screen on the bottom of these things. Check out the silk screen that shows you the links there going across. and of course they've got uh, surface mount passive components on the back of this board. but they do go into a lot of detail and they label all the Uh points as well.

So the the other thing you'll find is that we'll probably have a look at if we can. get at the service manual for this thing and you'll probably find that uh there. These things are designed to be serviced and the service manuals are uh, absolutely works of art in their own right. So anyway, Let's uh Power this thing up and uh, have a probe around on this Mains board and see what's going on.

And the other thing to note here are these wires that they've used to sort of sec cure. There you go We I've seen these in uh in gear. we saw it a couple of videos back but they're holding all that stuff in place with just these bent wires. They're everywhere.

look holding down these cable looms so they'll be solded into the bottom of the board like that. Look, they're properly crimped and everything. so they're crimped solded into the board and they just bend over like that to keep the wiring Looms in place. Really quite nice.

They've got those everywhere all over here. Look, they've got just keeping those Main's wires there. uh tidy. they're they're all the same color, they're all blue.

We're down here keeping a couple of other a little uh Transformer tap down there. all nice and tidy. and I I really like that. Look at that.

keeping a ribbon cable down one the flat Flex cable down there in place. It's really quite well engineered. I Love this thing and check this out. I Love it this.

PCB here. it's got no traces on it whatsoever, no components. Its sole purpose is to just retain this flat Flex cable and these other wires here using these wire retainer. Clips Like this: I mean they've they've You know? this is all still pretty tight in its own right.

like you know, but they've gone. Oh, we can't just have this flapping around in the breeze like that. What if we put the case on like this and it pinches it or does it? Oh, that's bad engineering. No, let's you know.

design an engineer another board. you can see the breakout tabs on there, it's been panelized and they've you know, gone to the shubble. They've gilded the Lily here just because they could. or they thought they had to cuz it's good engineering just to hold those wires in place.

I Love it. Now this Mains board here. we can uh, see the Main's cable coming in here. It's only a uh, two wire one, so it's um, uh, double insulated so the shazzy isn't Earth just in case you're curious there.

and there's a few fuse down in there, but it looks intact. It's definitely not the fuse blowing and uh, you can see this relay in here, which uh, I'm pretty sure S I haven't traced out the circuit on the back of the board yet and that's a good thing about this. It's all single sided. You can easily trace this out, but that Reay I think uh, switches this Mains the mains Transformers here and so it just switches that Mains from there over to here.

So um, I we we can verify that by measuring the back of it there, but there doesn't seem to be anything obviously blowing on this board really. But look, there's a uh, there's a diode Bridge there which is full wave. Looks like it's full wave Bridge rectifying directly off the Main's input and aha, that's what I was talking about before. That is the standby DC Todc converter using this Transformer here and there's some opto couplers over here.

That's the thing that's going to be drawing the 0.1 watts and obviously that is continually generating a uh a you know, a DC rail or a DC rail or two to power the standby power circuit. And because there's no other wires coming off this thing, it goes through a board-to-board interconnect header right down the bottom there. So clearly it's got to go into this board. and then this board has to go all the way out somewhere else because if you have a look I mean you know it's uh, this.

Well, you can't see all the wiring in here. it's hard to show, but then it's got to get all the way over to the soft power button over on the front here. And and yes, there is a Transformer tap coming off here going over to this board. but I think the DC voltage is eventually coming out here.

I Don't think this thing's powered up at all. I mean we can actually measure that and uh, see. but I don't think this Transformer is powered up at all. So let's get the meter and start measuring.

Okay now, I've got this thing powered up and this is immediately very dangerous. When you're working on live gear like this, you should ideally have a Main's isolation. Uh Transformer I don't because I don't repair enough stuff I rarely repair stuff like this I'm not in the business so I don't have a Mains isolation Transformer Um, but that's a good thing to have. You need a residual uh Earth leakage, uh, circuit breaker in your box and you always work one hand keep it in your pocket when you're Pro I mean obviously you can't always do that because sometimes you got to have two hands like this to probe things.

but definitely don't walk up to the thing and you know, sort of lean. Uh, you know, have one hand on the shazzy like this and then go poking around inside the damn thing. I mean this one isn't Main's earthed. Okay, this is double insulated so the Shaz is not Main's Earth so it's a bit safer in that respect.

but in a Main's Earth one if you're just you know, casually leaning against a thing like this and you're poke out inside, you can kill yourself. so just be careful when you're doing this. Anyway, let's have a measure here. Let's measure the Main's input.

so we've got AC volts. We'll just make sure we've actually got 240 volts coming in. Yep, we have 240 volts and see if we have 2 40 volts going out to this. Main's Transformer here.

No, we got zip folks. So that relay is not um, turned on and it's not not switching that voltage through. so this Transformer is off. so this extra wire is not going to be doing anything at all.

so it's all in the standby power supply part of this circuit. All right now. let's probe this. uh, Diode Bridge rectifier I told you about I'm going to probe it there because I can.

It's easy and the other one is up here. I'm on DC volts now because it will be filtered. TDA Oh, that's jumping around a that's jumping around a little bit 340 240 Who that's that's jumping around I Expected that to be fairly smooth. DC You can see the bar graph really, really flickering there and uh, I don't think that is particularly that great.

So um, have we got some sort of uh filter cap in there? It's worth having a look now. Curiously, on the board here, you can see all these black texture marks. Um, it's almost as if like somebody's like checking off test points or something. and there's a number three written there.

It's almost as if somebody might have had to go at repairing this. but I don't think so. CU I See um, similar marks on all of the other boards as well. So I just think it's some sort of, um, a test at the factory.

Some sort of factory test? Mark each one's you know, probably hand tested or something like that, or hand checked. and uh, they've marked this thing for some reason I don't think it's a repair marking now just before I check that cap in there I Can see through here I won't bother trying to get a shot for you. It's not that interesting, but I can see a point marked uh, plus 5? Vols um, plus 5 like s or something. So it's probably standby.

So I'm going to probe that sucker. Aha, there you go. 4.79 that's actually. um, it's I mean technically, it's within the, uh, typical 5% spec of a 5vt rail, but it is kind of suspiciously low.

But we certainly are getting a 5vol rail there, which, uh, which is presumably the standby rail which goes through to the soft button power circuitry now. I've taken this Mains board out of here here and check this out. Another nice little touch. Yes, it is disconnected by the way folks.

Very nice little touch on here. You notice how that we could only access the back side of the board before? What have they done? They've added in these little test points. Look at these little links here like they actually go absolutely nowhere, but it's a test point for that. It allows you they've you know, routed out that slot there in the bottom of the board, so that and put that link across so that you can get your oscilloscope probe through the back of the board and onto these test points.

Absolutely brilliant. They really thought about service in when they design this thing and yes, I could actually try and download the service manual for this thing. but uh, I'm I just want to muck around with this thing first. I Don't want to.

uh, take the easy option buger that. So what we've actually got here is, let's just have a look at where of what, uh, what's going on here. We've got our Mains input here. This is our Main's input connector.

here. It goes down to this transform to this relay. You can see they're actually labeled on the back relay. so these are the two relay contacts.

Here's the relay coil over here so that contact when it switches it goes through to the fuse and this is the fuse here. So the fuse has actually, uh, got nothing to do with all the standby doesn't protect the standby power circuitry up here. It's only for the Transformer and this is the connector which goes off to the Transformer So that's basically all you know. that's pretty much all of that fused main side of it is just there for that.

uh Transformer to switch in. And of course the relay is switched from this low side this board to board interconnect down here. It's just got a uh a pin which goes up and switches that Reay on. now as a bodge hack to fix this thing.

I could of course just uh, force that Reay permanently on. So when you're plugged in the mains power bang, you know it. uh it actually uh Powers the thing up or even short the relay completely and then just uh Power the whole thing up. So getting this thing to power up um is is Trivial I can manually override that thing and uh here.

of course the other Mains input of course goes off to this Dio Bridge here. So here's the AC input here on the Dio bridge. This is the DC output here. It's got a filter cap 47 Nanofarads yes, I've measured it.

Yes, it's good. Um and uh. then we've got a bunch of uh, switch mode control uh circuitry on the high side here. Uh, the Transformer is uh down over here.

sorry. so it links in. so there's the Transformer. There's a link.

You can see the link going directly over there, from the diode bridge going over to the primary side of the Transformer. the secondary side is over here. These are the opto couplers for the feedback and uh, that is about all she wrote on on this board. So there's not a huge amount.

There's standby and as I said, I've measured that + 5 there I'm getting plus uh 4.8 which uh, should be good enough. And just to give you a look at these surface mount parts here, you can see those little red blobs coming out from under those little Uh 805 resistors there there. That's the Uh glue that holds it down in place while this thing gets wave soldered. So we' got to p Couple of passives here.

Here's the Uh transistor. There's a transist, there's a T92 transistor on the other side which drives the relay here and uh, and just a quick check on the Reay here. I think I've got it around the right way. Yep, you can hear the Reay going, so not a problem at all.

And of course, the other thing that's needed is the 12vs to drive the relay over here. So this is this output here and this should be 12 V So let's check. Let's check this, shall we? Oh, 10 10.6 It's jumping a bit over the place. that's suspiciously low I would have expected that to be 12 Vols Because this is a 12vt rated relay, it doesn't actually say it's 12.

Vols it's not marked on here. Maybe if I check the schematic service manual, it might say that, but I might try and load that down and see if that drops. Okay, so what I'm going to do is I've got the Agilant 1272a here and that's got a low impedance mode so I'm going to use that low impedance mode I switched it to measure DC There, it's mainly for AC but it also works for DC as well. And let's there we go.

It's still 10.5 Vols So even when you load it down with a few k um, it is still reading there so that that would still be enough to pull in that relay though. but I don't I don't know. It just seems suspiciously low to me. And for those who are curious to see an LCR meter in action, uh, measuring ESR in circuit as opposed to, um, a more specific instrument like this Bob Parker ESR meter here? Um, here it is.

I've got the Agilent U 1733 C and uh I've got it set to 100 khz so no there 10 KZ sorry I was McKing around 100 khz. There it is and we're getting 07 Ohms this is a 30 300 mik uh 16v cap so that's pretty much the expected uh value I Don't think it's a certainly gone high and you can see that change with the frequency. This is 100 htz. it's going to jump around there, it's going to increase bang.

So we're talking 7 Ohms at 100. Yeah, it's all dodgy at 100. Htz doesn't like it 120. That's at 1 khz and that's at 10 khz.

It drops a bit more and at 100 khz it gives you your lowest figure as you'd expect. so that appears to work in circuit. It's another thing I'm easily able to check and that is that is there a signal actually getting to I'm pressing the power button on the front here. Is there a signal getting through to that rear light? and no, there isn't.

So it's not like the transistor circuit on that relay is dead or something like that. So I think it might be time just to Simply Uh, bypass this thing and uh, you know, just jewelry, rig it, turn on the Reay there and uh, see if the whole thing Powers up. All right. So what I've done there is just sold out a 10K on the other side of that resistor, so straight into the base of the Reay Drivin transistor to the 5V standby.

So as soon as you power this thing up, the Reay should come on and bang. It should just override that uh, soft power relay without interfering with anything because that other series resistor is still there going off to whatever circuitry the soft start circuitry which is designed to power this thing. So let's power it up. give it a try.

Here we go. think I heard the relay I Heard a relay go but nothing's pairing on. Bummer and well, it is definitely uh powered on. It's drawing 44.2 Watts but uh no.

I'm getting absolutely nothing so looks like there's something else horribly wrong with this thing. So unfortunately I don't like the look of this at all. I mean here's the uh little switch board and yes, I've checked the tactile switch and yes, there is now voltage coming out of this Transformer tap because we're Force the relay on and you know the whole thing's drawing 42 WTS and it's powered on, but the pro processor in the thing somehow doesn't realize that it's powered on obviously. Now if you're curious to see this thing without the front paddle on it, I was able to take that front faser off and it just lift it off and you can see the tactile switch is still in there.

They just go directly to the board behind it and the uh lever power button over here and it's all rather intricately uh designed and this thing just uh comes off here on these plastic hinges like this. You undo a couple of screws and you can actually get that front panel out to actually access it. so that's not too bad I thought I had to take out all of that stuff in there, but it turns out I didn't So what I can do now that I've got access to the back of this board? I can actually follow the soft power switch over on this board here and I have actually checked it does short out and it goes over to here and I can see the Uh CIS power line coming in there. So I can follow that all the way over there it is.

you can see it. Sis Sis Power There it is. So that's that's the power switch. It comes in here looks like it's got a pull up or pull down resistor there and presumably a pull up and it links over to here like this jumps over and then I can follow that trace.

It doesn't go to this puppy, so it's crazy. It looks like this soft power button goes all the way through this wiring harness here. onto this board through here. it's got a pull-up resistor, goes all the way across here, across here, off to something.

oh maybe something else in there. I'm not sure what and then out this flat Flex cable goes all the way over here and then it pops in this board all the way over here and eventually goes into this main processor chip over here. Oh man. Okay, what I've done now is I've unsorted that bodge resistor I've put on there.

So so it's in its original condition now. I'm going to see if I get 5 Vols on this board because there should be 5 Vols coming all the way from the main Uh board over there. generate well, 4.8 or whatever it is, it goes through that bottom board, down the bottom with the big caps on it, and then it comes up this ribbon cable. Here, this flat.

Flex cable. Onto this board. It's powering this processor over here. Then it's coming through this flat Flex cable all the way over here to the pull-up resistor.

On this point here. Crazy. but uh, that is the uh, that is what's going on here. So I'm going to measure.

where's the pullup resistor again. There It is right there. So on this side of it, we should get 4.8 volts. And yep, we do.

There it is. So we're getting our voltage all the way across the bloody system all the way over to here and let's have a look at that point there. 4.8 Vols It's the pullup of course. So if I push this switch over here, it should drop to zero.

Bang. It does. So that soft power switch is working at least to this point here, and presumably all the way over the flat, flex and all the way to that processor. And I've managed to prize this board out here and it was a bit of, uh, effort.

There was one screw holding it in the back up here on this, uh, metal, uh tab, right? This metal threaded? uh tab here. But look at all the connectors which connect all the different boards across here. Five boards. Look at the system design involved in this.

Just from a mechanical point of view, you've got the you know, it's it's It's a motherboard design essentially an inverse motherboard design with these board-to-board connectors and that sits in there like that and joins all five of those boards together. You can see the black marks on there like that and it it lifts off and this is clearly I Mean you know there's not much on the top here. as you can see, they're mostly all links. Once again, it's a singles sided uh board they've got happening here and uh, really? oh I see a uh, we've got ourselves a backup battery on there that's worth measuring, but surely that wouldn't uh stop the thing from working.

But apart from that they got a couple of other caps which looking reasonable condition. So yeah, I don't know. um let me measure that battery. sorry that's not actually a battery that is a super cap and uh yeah, it's got some voltage on it so it is, uh, charged up in standby mode.

but well, oh man, hope it's not the main chip gone, but there's something going on. Maybe it's not detecting something that I don't know which is stopping it. You know, some sort of sort of safety mode or something to stop it from switching on. It's getting rather complex now and there was only one way to verify that and that was to look at the service manual and I was able to download the service manual for this thing no problem at all.

I'll show you the whole thing in a sec cuz it is a bit of work of art, but this is what we're interested here. This is the powerboard which we're looking at. You can see the Uh Mains input over here. Here's our switch mode: uh Transformer Here with our Bridge rectifier.

there's the Uh switched output for the Reay the relay is down here and this is our output here and you can see that these Uh numbers in red or is it pink or something? they're they're telling you. 6.3 Vols AC out of here and typically out of that dire Bridge 10.3 volts and that goes to the 12vt Reay So there you go. Um, it is. um, fine and dandy and the 5V uh rail? of course that's so that was the S10 uh thing.

I measured point I measured at 10.3 Vols Now unfortunately, it gets a bit more complicated. I've uh, taken out the little Uh switch uh Power front panel uh tactile power switch board and you know there's nothing on it except a tap. a 5vt tap from the Uh Transformer which I've checked and there is voltage there after I've uh, modded the relay to switch it on. so I'm getting 5 volts into there I Don't know why they need that extra Uh tap coming off, but they've got the tactile uh standby switch and that goes to the Um net is called PSW So if we search for PSW we get um.

if we get the correct board that's not the that's this service manual is for different Uh models so you have to be careful. Here we go. Now that's the V457. We want the V557.

so if we search for Nets here we go. Go. What's this there? There we go. RXV 557 So this is the Uh Wir in harness going off to that board there and it's coming in and well, you know it's getting reasonably complicated here.

It's going all the way around here into this huge Um LSI device here and well, jeez, who knows how this Um soft power on function works. Seems to have some sort of Transformer uh uh, feedback kind of winding on it, but that isn't activated until you actually activate the power switch and it's all getting rather quite messy and I've forced the thing on and it doesn't Nothing comes on the screen at all, nothing seems to boot up, but that's because. uh, the um. that's because the microprocessor probably doesn't know that it's been switched on because the switch didn't come on and there's something else happening there.

and I don't know. it's getting really, really, uh, ugly pretty quickly. I don't like it now I Found this little block diagram here hidden away in the Uh service manual. and here's the power supply board here.

Here's the power relay that we're trying to switch and it shows another one IC 452 which uh then supplies various plus 5 volt rails and power save mode and all that sort of stuff. So I see 452 is what I might try and find and if we get in here to IC 452 I've found it over here. here we go. that's our that looks like the input.

there we go 10.1 Vols and our output is 5.42 and here we go here it is over here I see 452 which is a linear regulator. It takes that 10.1 Vols input that we get from that S10 that we were looking at and it outputs um, it looks like it permanently outputs um various. uh well you know a 5V rail. uh basically for plus 5 Vols Buu plus 5 Vols M plus 5 Vols s and then there's this P detect signal and it's all quite complicated and this C1 and C2 here.

aha look this tied into this reset pin which goes off onto this board somewhere up here. You follow it all the way up here and it goes out there and it's that goes off to the main board. Oh it's crazy. but anyway C1 and C2 they actually give you couple of screenshots down here.

Check it out. Power on Power off you you connect the power cable, disconnect the power cable P there's a power on Logo in power pulse there so you know I mean it's all the info is here. but jeez the system design of this thing is just so convoluted. Ah, no wonder it's taken forever.

Well, unfortunately I think I've spent more time on this thing than it's bloody well worth it's a bit Elusive and I've probably missed something obvious, but the um Power detect signal on the main board here is fine. The reset signal is fine. I've checked that the power the standby power rails are all fine on both boards up there and this one. I'm able to manually override and activate the rear lay I was able to do that when it was all uh, powered up I didn't use the pull-up resistor I was able to probe through there and activate the Reay and still nothing.

um switches on it. doesn't matter what I'm what I try and do to this thing I cannot get the Beast to power on so I don't know I've probably missed. Maybe there's something obvious I don't know. read the service manual more.

Yeah, perhaps. but H it's not going to happen today. sorry H just waiting for all the flame. YouTube Comments: you missed this.

You missed that? Yeah, right. PR Box 7949 bham Hills New South Wales 2153 Australia give it to me in writing. Anyway, yeah, I'm a bit disappointed I Thought this would have been easier than uh what it has been, but h no it's a little complex beast in terms of the Uh system of powering this thing up and all the different rails and stuff like that standby rails. it's just crazy H it's all over the shop anyway.

uh maybe I'll have another hacker it in the future. So there you go I hope you enjoyed that even though we didn't get the goods in the end. but oh well, it's It's not a bad dumpster dive anyway. even if this thing is um, scrapped and I do and I never managed to get the thing working, there's some great Parts in here so well worth getting.

So anyway, if you like tear down Tuesday please give it a big thumbs up and if you want discuss it, jump on over to the Eev blog. Forum Catch you next time loser.