EEVblog #446 - Dumpster Diving Samsung Plasma TV

[tom66]

I'm watching one I repaired right now. The technology has come quite far, but it still doesn't look quite right to me -- I'm not sure why, I can't put my finger on it.

[free_electron]

the dead giveaway on those 'caps' is the writing : 10uH   

they are the integration inductors for the class-t audio amplifier

[tom66]

Probably just class D. They're to limit the EMI produced by the switching output.

[ZeroStatic]

If the analog inputs are not working, I'd suspect a voltage rail is down in the input processing section. Check the rails around the philips SAA7119 chip.

[AndyC_772]

The technology has come quite far, but it still doesn't look quite right to me -- I'm not sure why, I can't put my finger on it.

I feel much the same way about LCD, even the best screens have a slightly smeary, almost greasy look to them which I just don't enjoy watching. For me a plasma screen was the obvious choice when I finally decided to upgrade my 10+ year old CRT.

[tom66]

Some other corrections (sorry Dave!)

Those Y-drivers are actually TQFP ICs (not BGA), each is usually 64~96 bit, with older sets having lower densities. By the way, that is minimum 64 channels capable of switching 200V so the IC design is not trivial...
http://www.fujielectric.com/company/tech/pdf/r51-2/07.pdf

The glue is necessary because humid air can otherwise lead to early failure.

The X-drivers are by necessity bonded onto the panel. With 1024 lines x RGB you need = 3072 columns, over approx 100cm you need ~31 columns per cm minimum (0.32mm pitch.) That's beyond the density of typical connectors -- not impossible but expensive. Each TCP IC switches 256~384 channels at around 70V, newer ones are 55V using different panel tech, some really early panels used 85V.

Vs is determined by the gas pressure of the plasma panel. My dad's old NEC has a 165V Vsus, but most newer TVs are around 200V as panel technology improves.

[Agony]

the SAA7.... chip thats on the yt video "pic" just looks soo wrong... it just looks as if it got a little too much heat.
Cant read out the complete info.. but partial search  shows its a digital video decoder.

[NiHaoMike]

Have you tried the HDMI input?

[tec5c]

P.S Plasmas are banned in some countries due to excessive power consumption.

More like severely restricted... they still exist but the brightness is turned way down to keep power usage low. First thing I would do is go into the service mode and set it to make it think it's in the US or another country... boom goes up the brightness.

No. They are definitely banned in certain areas. The state of California has had a ban on the sale of plasma TV's since 2009. Put in place by the California Energy Commission center. Since this was put into effect, manufacturers have revised their technology to ensure that their products meet the energy consumption laws.

Plasma is a dying technology, it won't be all that long before they won't exist on the market in any country. Panasonic had the choice some years ago about which technology they would invest in. They chose plasma and built manufacturing warehouses. Now in retrospect, this was the wrong choice and they are fully aware of this. Panasonic now have a plan in place to get out of the plasma industry and within a number of years they will cease to manufacture any more plasma units.

[M0BSW]

Well the Samsung TV seems to have lasted longer than my Samsung Cell phone, 10 months and it's knackered 2 months warranty left, wonder if they'll fix or replace, on the video that was the first time I've ever seen inside a plasma, I was given a broken LCD TV the screen was seeping, I thought there be lots of good stuff in there Wrong two boards power supply, and a main circuit board all surface mount, using the power supply, rest in the recycle bin.

[tom66]

No. They are definitely banned in certain areas. The state of California has had a ban on the sale of plasma TV's since 2009. Put in place by the California Energy Commission center. Since this was put into effect, manufacturers have revised their technology to ensure that their products meet the energy consumption laws.

I can only find proposals for California banning plasma tech. I don't think they've actually done so yet. They have mandated energy star requirements (IIRC so has every other state) which makes them much less attractive.

I think I'll keep my 4 year old Panny... I'm not bothered about the power bill yet...

Plasma is a dying technology, it won't be all that long before they won't exist on the market in any country. Panasonic had the choice some years ago about which technology they would invest in. They chose plasma and built manufacturing warehouses. Now in retrospect, this was the wrong choice and they are fully aware of this. Panasonic now have a plan in place to get out of the plasma industry and within a number of years they will cease to manufacture any more plasma units.

Panasonic still makes plasma, about 5~5.5 million per year. Samsung make approx 4.5 million. LG make about 2.5~3 million. (LCD TV shipments are around 200 million, so it's a small piece of the pie.) Neither are in a rush to drop the niche technology yet... but they'll probably be gone by 2014~2015 though as OLED steps up to the plate. Panasonic are heavily investing in OLED with Sony, so that's where they will probably go.

Trouble I see for the TV industry is "where next"? OLED is almost perfection: Infinite contrast ratio, sub-millisecond response time, extremely good energy efficiency, very high colour depth.

You can't really improve it so will we have another stagnation like CRT tech for ~70 years until someone invents something like holographic true 3D displays? Meh, I hate 3D TV anyway.

Another thing I don't like about OLED is it is boring. Everything happens on the display panel. No high power electronics! I want big heatsinks, cooling fans, and a beefy power supply, like in a plasma.

[Rodville]

After watching the follow up I am more convinced then ever that there is either a loose cable or broken solder joint.

[Fezder]

After watching the follow up I am more convinced then ever that there is either a loose cable or broken solder joint.

followup? oo, gotta watch that. even if i would'nt understand half of it....

[Erwin]

What about this? That does look broken. 

[NiHaoMike]

Another thing I don't like about OLED is it is boring. Everything happens on the display panel. No high power electronics! I want big heatsinks, cooling fans, and a beefy power supply, like in a plasma.

Throw in a Core i7 and some nice GPUs and you'll get all of those.

[tom66]

Another thing I don't like about OLED is it is boring. Everything happens on the display panel. No high power electronics! I want big heatsinks, cooling fans, and a beefy power supply, like in a plasma.

Throw in a Core i7 and some nice GPUs and you'll get all of those.

Hah... the newer TVs are coming out with quad-core 1.3GHz processors now.
Give me a "dumb" TV any day over a silly smart TV.

[Monkeh]

What about this? That does look broken. 

... there's nothing wrong there.

[Erwin]

What about this? That does look broken. 

... there's nothing wrong there.

I agree it could be a shadow of a solder blob on top, but from what I can see in the video, it does look like a crack in the solder joint. (that black streak has some very high contrast difference)

Edit: That thermal stress on the '10-bit video decoder' could well be from someone with a hot air gun, trying to repair it.

[k8tek]

Nothing beats the old console CRTs.

[NiHaoMike]

Hah... the newer TVs are coming out with quad-core 1.3GHz processors now.
Give me a "dumb" TV any day over a silly smart TV.

It would actually be quite interesting if they designed a TV that could run Windows or whatever x86 OS you wanted (like Linux). Or an ARM based TV that runs Android. A smart TV is actually great if done properly, but I'm not aware of any that are.

On the other end, I think there's quite a market for dumb TVs that are really just big monitors.

[leno]

This could be the the remote

http://www.ebay.com.au/itm/Replacement-Remote-Control-for-Samsung-PS42S5H-/111004759569?pt=UK_AudioTVElectronics_Video_RemoteControls&hash=item19d8663611

or one with a busted screen may be comes with a remote and u could swap the digital board to see if it fixes it

http://www.ebay.com.au/itm/Samsung-42-Plasma-PS-42S5H-/221207079316?pt=AU_Televisions&hash=item3380f82994

[adcurtin]

Hey Dave,

No one else has mentioned it, but it looks like you're using the Hauppage HD-PVR as your component generator. The HD-PVR does not generate a reliable component output when there is no valid input. My monitor (Dell u2410) despises the output and sleep mode goes in and out of sleep mode when there’s no input to the PVR. It's like the PVR is outputting a valid component signal for half a second every 5 seconds or so. Maybe it's the processor waking up the ADC to see if it's got an input yet.  Anyway, I wouldn't rely on that signal without a valid input to the PVR. I’d suggest trying a different component source.

Cheers.

[tom66]

I want the TV to be a large, 1920x1080 display panel, nothing more. If smart features are included this adds a path for the TV to go out of date. I think this is the only way manufacturers will be able to "improve" each generation, with more/better smart features.

[hammil]

I want the TV to be a large, 1920x1080 display panel, nothing more. If smart features are included this adds a path for the TV to go out of date. I think this is the only way manufacturers will be able to "improve" each generation, with more/better smart features.

Then buy a basic display panel, there are plenty of them... Like those used for computer displays.

'Smart' TVs started out by integrating the digital tuner into the body of the TV, which gives a much more seamless experience for the consumer, hence their popularity. As technology developed, companies started integrating more features, such as streaming, and even web browsing. If some feature doesn't fit the bill, the consumer is still free to plug in an external box, but in most cases the built-in variants are reliable enough to use.

Even if you bought a simple display panel, it will still eventually become obsolete. Huge flat-tube CRTs cost thousands, at one point, but now are almost useless. The first TFT displays were truly awful. And when we're all using millimetre-thick OLEDs (or similar) with million-to-one contrast ratios, we'll laugh at how silly we were with our plasmas and LCDs.

[kfitch42]

It would actually be quite interesting if they designed a TV that could run Windows or whatever x86 OS you wanted (like Linux).

I think that exists, it is called an iMac.