A quick follow-up on the Samsung Plasma TV dumpster dive.
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Hi, this is just going to be a quick follow-up on this Samsung plasma. TV, because I Wanted to test a few more things, didn't have enough time last time. So We'll check this sucker out, shall we? See If we can at least get an external signal working. So Let's give it a go.

Now The problem last time was that none of the analogey type inputs worked at all.. The Component video didn't work, the SVideo didn't work, the VGA didn't work, and-- but I didn't try the HDMI. So I'm going to try the HDMI and-- now. Also A lot of people suggested it might be something incredibly simple that was just due to the blue screen mode that I had turned on.

So We'll disable that, and we'll give it a go.. Now, I've got the thing plugged in now. Now This one-- This board is completely safe to touch because it is isolated from the mains supply. And You'll notice that they have a high-voltage warning sticker up here, that is for the rest of all of the circuitry which we saw last time under there.

That's all the high-voltage stuff, you do not want to go poking around in that. But All this-- all low voltage, 3.5 volt,, 5 volt stuff, all mains isolated. So It's completely safe. So That's why they have the warning sticker on this part, and then a separate removable panel on here.

It Just allows servicing and repair on just the completely safe side of the thing. That's just a little safety aside there.. Now I've got this thing turned on and it is actually powered up, and if I do the old back-of-the-finger test, that chip there is getting quite warm. Let's zoom in on that.

That's the old back-of-the-finger test. This One is-- yow! Hot, hot, Burney, Burney, burney.. Whoa, that's the-- the main Samsung BGA part there. That's just the memory there.

That's another-- some sort of video processor. A Little bit warm, that's the HDMI panel link. That's doing nothing. That's a little bit warm.

This One's here, not a problem. So We're just searching for any parts that are particularly hot. Now This one,. A few people commented that it looked like it may have been burnt out.

So We'll take a closer look at that under the Times Ten macro lens. But It's-- it's warm, so it's powered up. But It's certainly not-- it's getting warmer, warmer, warmer. So I Don't know if that's normal for that device,.

we'll have to check the datasheet. Ooh, that one's-- that one's pretty hot. Geeze. We'll have to check out what that one is.

And The others.... Not really a problem. So Let's take a close-up look at that one. As I Note: in the previous video, it seems to be the decoder for all of the analog inputs down here,, the component, the SVideo, the RGB, and all that sort of stuff.

Because All of these AC coupling caps down here and you can just see all the traces flow from there into there, and possibly this chipset down here as well. But That one we're interested in, so let's take a look at the datasheet for that one. I Couldn't get the precise Philips datasheet, but I did get a second source one here from Trident Semiconductor. And No surprises.
It's a 10-bit video decoder with comb filter and component video. 4 studio-quality ADCs, 16 analog inputs. And I Can link this in to the notes down there, but it's, you know,, it's got all sorts of-- it's got the composite video input,, it's got the RGB inputs, it's got the component inputs, and everything you'd expect. All that-- all those inputs which aren't working.

So It's-- you know,, a fair guess that that chip-- that there's something wrong with that chip in there. Because We know that all the video processing around here all works, because it's driving the panel just fine. So Rather than troubleshoot that right now,, first thing I'm going to do is by-- essentially bypass that chip by not using the analog inputs, but using the digital HDMI input that'll go through the separate HDMI processor here,, and presumably directly into the processor up there. So Let's plug in HDMI, see if it works.

Alright, here we go. Plugged it into my notebook down here before, HDMI. And As before, we've got that blue screen. We'll switch that off in a minute.

But Let's change our source down here. You Ready? Tada! There You go. It Works a treat! As expected, HDMI works fine. Now We'll still cha-- check that blue screen thing to make sure that's not an issue.

But There we go,. we bypassed that video-- analog video decoder chip, and went straight through the HDMI. And That is perfect! I Mean there's no dead pixels, there's nothing, it doesn't quite go right to the edge down there, but that-- that is beautiful. That works just fine, I Love it.

Let's play a video on here, see if the audio and everything works. Tada! There you go! Working A treat. And The audio's-- as you can hear, is coming through the TV. No problems.

Beautiful. We Have a winner folks. Check it out. Okay, I've turned off the blue screen mode and no,, the PC input does not work.

And yes,, I've set it to the resolution possible, 800x600. If It can't do that, seriously, it does not work. So The VGA input is definitely cactus. But folks, woohoo! Check this out.

I Am getting something on the composite video input now. I've got one of these VGA to composite converter box-- boxes which is generating the colour bars there, but it's-- it's flickering. Check that out. So I Don't know whether or not that's normal, I Haven't used this box before.

But it-- yeah, I Don't know whether or not that's the TV or the box outputting something. But I Can't seem to make it, you know,, stable or anything like that. So I Don't know if that's a fault with the TV or the generator box. Nope, bluescreen mode's on.

So There you go, I'm-- so it wasn't that. So I'm not sure why it suddenly decided to work. This is the same box I was using yesterday to test this thing. So I Don't know what the deal is there.
But Composite is working, so that means that chipset is actually processing something. At the very least--. I Mean,, it can't do that, there's a lot of complexity involved in doing that. It's not like a-- I Don't think part of the chip's going to fail with the VGA input.

So Not entirely sure what the issue is. And What do you know? It does actually work A treat. So It was that box generating a non-compatible composite signal in some way. I've got it now.

Hooked up to a old DVD player with the composite output, and it's working A treat! So I Don't know why that wasn't working the other day. The thing has suddenly decided to work. Did I Actually press on the chip or do something weird like that? It is one of those BGA chips, so you know, I-- presumably I Can only think that I did actually make the chip come good. Maybe It does have a dry joint on one of the balls underneath the BGA or something like that.

Maybe We can try some freezer spray. So What I'm going to do now is freeze this BGA chip to see if it does anything. Don't have any freezer spray here in the lab, but the next best thing: air duster. You've seen this before, just turn it upside down, instant...

freezer spray. Let's go, let's see if I can get in here. Here we go, I'm going to hit that BGA chip and see what happens. Nope.

Chip's going all frosty. I've got Frosty the Snowman on that BGA chip and it's holding in just fine. Not A problem. And If you want to have a look, it's still cold.

Here we go. Aww no, it was. It was cold for a second there. But This is what it looks like when you freeze it.

You Get all the frost on the chip, like that. And There you go, it's nice and cold. And it's still working. And Just to show you that blue screen mode.

You Can see there's no signal, it's turned off. Disconnected, it's got the blue screen there. And You switch it on and it just automatically should.... hello? There We go.

Automatically switch-- there you go look! We've got some-- check-- check that out. That is not a clean signal anymore. So What's going on there, it was before. You Saw it before, it was absolutely perfect.

Now We've got this colour-- there's some sort of colour tearing across there. I'm not sure what the correct term for that is. But You can see it. Hopefully You can see that-- yeah, you can definitely see that on the screen.

There's that colour tearing on the display across here and down here as well. So I'm not-- there is something wrong with this thing. But It seems intermittent. So At least we got the thing going, I'm not entirely sure why.

Maybe I'll hit it with some more freezer spray and see what happens. Nope. Let's try... In the general vicinity.

Like the electrolytic caps and stuff like that. No, no, it's still got some tearing on there. So There you go. That is very interesting.
If You've got any good ideas about what's possibly going on there, then-- oop, no, it was good there for a second then-- then it's going it again. So If you've got any idea what's going on there--, I mean ch-- clearly the decoder chipset is working just fine, because you wouldn't get that unless, you know,, as I said, you can't get like a partial failure on that chip or anything like that. That's, you know, really not feasible at all. Whew! Your guess is as good as mine.

So This is one sick puppy here. Let's plug the HDMI back in. And does it auto-detect? No, doesn't auto-detect, but I can switch the source there. And There we go.

Nothing Wrong with the HDMI. So yeah, I don't know. Something's intermittent on this sucker, and-- but the HDMI works fine. Which makes this a very-- still a very usable set.

I mean you use-- ideally you want to be using the HDMI input for the best quality anyways.. So, it's a winner as far as that works. The Audio and Video: Absolutely first class for this, what, 8 year old plasma display. 2005 model.

And-- which, according to people complaining on the web,, this particular model has very high failure rate and was very expensive to repair after the warranty period. Which was presumably like 12 months for your standard warranty unless you got one of those extended warranty things. And No, the component video is not working either. I'm generating my component signal.

It's actually detecting that there's component input there, and it's enabling that particular channel when you cycle through the source here,. But I've got a component device which is generating component out, and zip. Now There are a few people who suggested that this Philips SAA7119 video decoder chip looked a bit burnt or something like that. It had some physical damage, and I've got to admit,, I can actually see sort of the shape of the die underneath it, but it doesn't get that hot.

And Of course it's working as we saw. It's at least doing something. So There's certainly no physical damage to the chip. And Yeah,, it does look a bit sort of thermally stressed I guess you could say, but I think that's just a natural part of the-- this particular package anyway..

So, I mean clearly there's nothing physically wrong with it, because it does actually work. Now Trevor From the Television Mag forum, he commented that I should probably do a service-- factory reset mode in the service menu on this thing. But I Don't have the service cable that plugs in the back of it, couldn't be bothered making one up, don't know how it works. And From what I'm reading, you can enter the service mode via the remote control.

So I Don't have a remote for it. We'll probably go out and get a remote now because it does seem to work, it seems to be useful. At least certainly in the HDMI mode, not a problem. So If you've got any ideas what's actually going on with this sucker, I'm sure it's something to do with that chipset-- that main decoder chipset.
But The freezer spray didn't seem to do anything. Bit Surprised by that. I Expected something to happen there I Guess, there was a good chance of that. But I Don't know.

I Need a remote to enter-- do the factory reset, maybe that'll help, maybe there's nothing physically hardware wrong with it, maybe it just needs a factory reset. You know, the I2C codes going to that decoder chip or something, to reset it. Eh, who knows. Anyway, I think it's an absolute winner.

Beauty. I'm going to-- not sure what I'm going to do with it. I Don't have a stand, so I can't just take it home and whack it in the lounge room or replace my other one. So It's either try and get a stand for it or mount it on a wall somewhere.

Could Even mount it on the wall here in the lab, perhaps.? Well The bloody thing weighs 50 kilos, so mounting it on one of these gyprock walls, eh, I don't know. And I've had a few people comment, do I always have bare feet around the lab. Do I always work in bare feet? Yeah, pretty much. It's much more comfortable.

But Occasionally I do wear Australian safety boots. Pair of thongs. Beauty. captioned by Sen.


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By YTB

21 thoughts on “Eevblog #447 – samsung plasma followup”
  1. Avataaar/Circle Created with python_avatars eric moeller says:

    I wonder if he knows that your not supposed to have plasma displays on their backs or fronts some how it damages it it will say it on the box

  2. Avataaar/Circle Created with python_avatars Monchi Abbad says:

    The analog processor did process the analog-background noise just fine.

  3. Avataaar/Circle Created with python_avatars Dar Dar Binks says:

    Working barefoot is fun and games til you stub a toe or step on a stray component.

  4. Avataaar/Circle Created with python_avatars meepk says:

    I like to think that the "dumpster" he gets all this from is really just a delivery drop-off spot.

  5. Avataaar/Circle Created with python_avatars Eric Kelly says:

    The screen is getting worse from freezing the chip moisture is shorting it?

  6. Avataaar/Circle Created with python_avatars Drick Lorenz says:

    i just picked a 2006 Philips plasma up off the street (had no remote). The plasma screen and many boards were Samsung parts. The TV had audio and menus but no input video. I did a firmware flash/upgrade via USB and all worked well afterwards. But that didn't stop me from cannibalizing it for parts.

  7. Avataaar/Circle Created with python_avatars manystar says:

    Btw Don´t you think maybe is software/service related problem instead of hardware? Maybe if u reinstall the software/firmware might recognize the ports? I´d use it with HDMI anyways considering is an old model though.

  8. Avataaar/Circle Created with python_avatars manystar says:

    Is there any cooling solution for this kind of tv? maybe installing some 5v fan coolers?

  9. Avataaar/Circle Created with python_avatars Rui Kazane says:

    color banding, not color tearing

  10. Avataaar/Circle Created with python_avatars Ronnie Ranyard says:

    Hi voltage Is doing it

  11. Avataaar/Circle Created with python_avatars Ryu Raccoon says:

    I'd put a scope on the power supply and make sure the clock is clean. Also, look at the composite signal input on the scope to see if it's between the chip and the input. Are you sure the board isn't cracked around all of the analog inputs?

  12. Avataaar/Circle Created with python_avatars SCOTTISH BULLDOG says:

    theres butane in most freezer spray lol!

  13. Avataaar/Circle Created with python_avatars Synthematix Music UK says:

    service menu is INFO, MENU, MUTE, POWER on the remote

  14. Avataaar/Circle Created with python_avatars Synthematix Music UK says:

    almost looks like a shielding problem, you will be able to get a replacement PCB cheap on ebay for this set.

  15. Avataaar/Circle Created with python_avatars Ben G says:

    HeijDmi XD

  16. Avataaar/Circle Created with python_avatars Juan Gonzalez says:

    I like this dude he reminds me of a hobbit.

  17. Avataaar/Circle Created with python_avatars John Garvey says:

    in the other video there was a wire that you said was loose. did you put it back in .or did they use that crap solder that forms crystal bridges on the chip set.

  18. Avataaar/Circle Created with python_avatars SonicHacki says:

    If you still own the TV, you can grab a multi-input to HDMI converter box.

  19. Avataaar/Circle Created with python_avatars James Last says:

    Samsung likes to run their components at their limit. With no heat sinks on those hot running ic's.

  20. Avataaar/Circle Created with python_avatars James Last says:

    Buy that board on ebay for 20 bucks.

  21. Avataaar/Circle Created with python_avatars taiwanjohn says:

    Perhaps the "burnt" analog decoder chip was a bit under-spec'd for the ambient current, and slowly degraded over time, to the point where leakage could occur (between the micro-components) under certain conditions. That could account for the intermittency of the failre modes.

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