EEVblog #446 - Dumpster Diving Samsung Plasma TV - Page 1
Forum section: electronics / general

author: David_AVD
author_rank: Super Contributor
timestamp: March 29, 2013, 11:57:20 pm
content: Could the "non working" PC input be due to it not supporting the screen resolution you fed from the laptop?

author: Rodville
author_rank: Contributor
timestamp: March 30, 2013, 12:28:48 am
content: I said this in the YouTube comments but I still think it could be a broken solder joint or even a loose plug.I had a loose plug on a monitor that was dropped. I just reseated all the plugs and it worked again. And as a reminder to me if not everyone else don't let your 4yo carry it for you no matter how much she screams.Sent from my Nokia 6185 using Tapatalk.

author: kfitch42
author_rank: Frequent Contributor
timestamp: March 30, 2013, 03:08:19 am
content: Quote from: David_AVD on March 29, 2013, 11:57:20 pmDoubt it. He mentions trying some other inputs @8:25, component and s-video. S-video at least should be immune to resolution issues.So we are looking at a fault that effects VGA, s-video, and component; but not over-the-air analog. My gut says that one of those custom chips takes in all the external inputs and outputs them in some format usable by the rest of the system. probably that chip, or something in its output path has failed.

author: Goophy629
author_rank: Contributor
timestamp: March 30, 2013, 03:10:36 am
content: How can I have that company build a garbage room here?just looking for a big screen here..

author: JoannaK
author_rank: Frequent Contributor
timestamp: March 30, 2013, 03:21:43 am
content: Quote from: Goophy629 on March 30, 2013, 03:10:36 amI know the feeling.. This Main PC of mine is 2008 wintage, and was not high end even back then, I'm sure many companies dump a lot newer Equip than this.

author: Rufus
author_rank: Super Contributor
timestamp: March 30, 2013, 04:57:17 am
content: One of those sold recently on ebay au for just under $200 pick up only.edit: meant $ typed £ - fixed.

author: Orpheus
author_rank: Regular Contributor
timestamp: March 30, 2013, 05:12:16 am
content: eBay AU prices in £ and not AUD?

author: daveshah
author_rank: Unknown
timestamp: March 30, 2013, 07:46:27 am
content: I wonder what would happen if Dave tried the HDMI input - maybe some analog circuit is broken? Also, could the 'Blue Screen' option interfere with anything?

author: M0BSW
author_rank: Frequent Contributor
timestamp: March 30, 2013, 08:33:37 am
content: Don't let this go Dave fix it, it would be a nice unit on the lab wall or in your home, if she who must be obeyed without question, allows it.going to keep coming back to see how your getting on with it.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 30, 2013, 10:28:36 am
content: Even if the various video inputs don't work, I think there's a clue that you got plausible video snow from the RF modulator, as if perhaps the tuner is still able to connect through to the processing and display circuits.Do you have a compatible RF signal available to test it with?Maybe there's a service manual which gives a block diagram; the tuner might not go via some piece of circuitry that the other inputs have to?

author: LaurenceW
author_rank: Frequent Contributor
timestamp: March 30, 2013, 10:52:46 am
content: Yeah, but380 watts??There goes the planet

author: hammil
author_rank: Regular Contributor
timestamp: March 30, 2013, 11:51:02 am
content: Aah! I was almost shouting at the screen...Turn off the Blue Screen mode!!

author: ecat
author_rank: Frequent Contributor
timestamp: March 30, 2013, 12:18:09 pm
content: Quote from: LaurenceW on March 30, 2013, 10:52:46 amMeh.That's only when showing a full white screen at full intensity... maybe. I did measure my old plasma once, rated at 320W but iirc it was closer to 100W in normal use.

author: tom66
author_rank: Super Contributor
timestamp: March 30, 2013, 12:26:01 pm
content: Plasma is an energy sucking beast. I got a 46" 1080p Panasonic for £70 on eBay as faulty, it was just a loose cable. It pulls around 350~400W on average TV (around 100~150W on darker scenes) and exceeds the rated 470W on certain scenes -- for example a high contrast noise pattern uses about 630W!! A 1080p display uses a lot more than a 720p display, due to the larger surface area to volume ratio of the pixels (more pixel wall to absorb light, less efficient cell.)However, overall, the reliability seems to be around that of an LCD TV. And the panels themselves are more reliable than LCD panels though vertical line failures are more common (which aren't repairable.)Dave, here is something to try. You will need to source a Samsung remote which operates the TV -- however, one for a VCR, DVD player or another LCD will work too.Turn TV into standby.Press Info, Menu, Mute, Power.Access service menu and perform a service reset.(If that does not work try Mute, 1, 8, 2, Power for some sets.)This fixes a lot of problems with Samsung TVs.I encounter more Samsung than any other brand in my repair adventures -- "Friends don't let friends buy Samsung."

author: ddavidebor
author_rank: Super Contributor
timestamp: March 30, 2013, 02:03:26 pm
content: yeeaaa dave nice dumpster diving!i agree with tom66... you can do a hard reset of the television... samsung tv are all bugged... i've one!

author: SeanB
author_rank: Super Contributor
timestamp: March 30, 2013, 02:27:36 pm
content: I buy Samsung Airconditioners.............. Some make it out of the compressor warranty.

author: Fezder
author_rank: Regular Contributor
timestamp: March 30, 2013, 02:32:47 pm
content: nice video, newer knew plasma's are such heavy & power hungry :S......but, looks good form inside, what i understand.

author: tom66
author_rank: Super Contributor
timestamp: March 30, 2013, 02:53:34 pm
content: Panasonic make far better plasma sets. The one I got is full of Rubycon. (Strangely, only a few Panasonic caps in it...) And much nicer overall construction -- only a couple of 'lytics on the main board (not like the Samsung one -- seems like the engineer may have had shares in electrolytic cap manufacturers?!)

author: JackOfVA
author_rank: Unknown
timestamp: March 30, 2013, 03:06:35 pm
content: If/when Dave gets the plasma TV working, please take a look at the RF noise radiated by the set - spectrum analyzer and a loop probe or even just a wire stub made by cutting back the braid and jacket on a length of coaxial cable.In the amateur radio world, plasma TV sets are notorious for radiated interference - so strong that they may be heard a km or so distant in the worst case and easily 300 or 400 meters. From what I've been told, worst signals are in the 3.5-4 MHz band, but unwanted artifacts exist up to 30 MHz or more.LCD sets are much quieter, so that (a) plasma TVs fail frequently and (b) are becoming obsolete are both good things for us radio amateur operators.

author: tec5c
author_rank: Frequent Contributor
timestamp: March 30, 2013, 03:26:21 pm
content: The blue screen mode will not effect any of the inputs. The purpose of blue screen mode is actually accidentally demonstrated in the video; When no/poor signal is being received, the unit will display the blue screen as opposed to the "snow" or noise.The fact that it powered up into TV mode means it was last used in this way as TV's have what's called power return. It seems unlikely that the inputs have failed although it is not unheard of.Dave, I have a few Samsung main boards from when I did my apprenticeship in "brown good repairs" (Old school trade name for Tv repair) laying around at my parents place.If you haven't got the unit working soon and we are still set to look at that old HP RF test gear then I'd be happy to see what boards I've got to replace it or fault find the dud.Catch up with you soon.P.S Plasmas are banned in some countries due to excessive power consumption.Jason (Thales)

author: topbood
author_rank: Newbie
timestamp: March 30, 2013, 03:43:41 pm
content: I hope this isn't considered cheating, but here is the service manual.http://rapidshare.com/files/1261898320/samsung_ps42s5hx_xex_d72a_sm.pdfI'd try composite video or s-video. They seem to take a different path to the Scaler. (pg. 23)

author: ecat
author_rank: Frequent Contributor
timestamp: March 30, 2013, 03:57:49 pm
content: The old plasma I mentioned in post #13 was 36" with a wacky 840×480 resolution. I just tested my 55" HD, on subdued indoor scene it pulled around 200W, a bright snowy landscape pushed it to around 450W, so average viewing is probably between 250 - 350W.Still, living in Scotland, it's better to think of it as a useful source of background heating, useful for 8 months of the year at leastEdit:Some of these TVs have a 'hotel mode' that is selected in the configuration. I think this mode allows the owner to restrict the number and type of working inputs so TV only for example would prevent users from viewing any video source other than TV.

author: tom66
author_rank: Super Contributor
timestamp: March 30, 2013, 04:01:17 pm
content: They pump square waves at 200kHz with around +/-100A current on the rising/falling edges (light emission), so they do produce a tad bit of EMI. Hence the heavy metal shielding. The EMI shouldn't exceed rated limits (i.e. no worse than a rated SMPS etc -- it's not as if there are exceptions for plasmas.) Older models were much worse but the newer ones are about the same as an LCD TV.The technology is pretty fascinating to study. High power usage so lots of power semiconductors. Dave's one there is an older Samsung using hybrid modules, i.e. all semis on one chip, so you're not going to see much exciting there. The newer ones do use discretes. The panel itself is actually a kind of memory module. The image is loaded into it by the column and y-drivers, then the scan sustain and common sustain drivers (the left and right boards) make the image appear. Each sustain pulse makes the written cells emit light. High contrast is possible, and motion performance is good too.QuoteMore 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. I love saving energy but I don't like LED TVs one bit. Holding out for OLED or FED/SED. (One Canon SED prototype used only 14W for a fully bright scene 400cd/m^2, damn impressive, sadly, it looks like the technology has been all but abandoned.)

author: ecat
author_rank: Frequent Contributor
timestamp: March 30, 2013, 04:05:33 pm
content: Quote from: tom66 on March 30, 2013, 04:01:17 pmI'm not a fan of LCDs

author: tom66
author_rank: Super Contributor
timestamp: March 30, 2013, 04:10:09 pm
content: 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.

author: free_electron
author_rank: Super Contributor
timestamp: March 30, 2013, 04:28:33 pm
content: the dead giveaway on those 'caps' is the writing : 10uHthey are the integration inductors for the class-t audio amplifier

author: tom66
author_rank: Super Contributor
timestamp: March 30, 2013, 04:30:49 pm
content: Probably just class D. They're to limit the EMI produced by the switching output.

author: ZeroStatic
author_rank: Contributor
timestamp: March 30, 2013, 06:08:56 pm
content: 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.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 30, 2013, 07:52:52 pm
content: Quote from: tom66 on March 30, 2013, 04:10:09 pmI 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.

author: tom66
author_rank: Super Contributor
timestamp: March 30, 2013, 11:20:34 pm
content: 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.pdfThe 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.

author: Agony
author_rank: Contributor
timestamp: March 31, 2013, 01:13:00 am
content: 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.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 31, 2013, 01:31:04 am
content: Have you tried the HDMI input?

author: tec5c
author_rank: Frequent Contributor
timestamp: March 31, 2013, 07:25:42 am
content: QuoteQuoteNo. 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.

author: M0BSW
author_rank: Frequent Contributor
timestamp: March 31, 2013, 08:54:13 am
content: 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.

author: tom66
author_rank: Super Contributor
timestamp: March 31, 2013, 10:49:17 am
content: Quote from: tec5c on March 31, 2013, 07:25:42 amI 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...Quote from: tec5c on March 31, 2013, 07:25:42 amPanasonic 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 isboring. 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.

author: Rodville
author_rank: Contributor
timestamp: March 31, 2013, 06:12:18 pm
content: After watching the follow up I am more convinced then ever that there is either a loose cable or broken solder joint.

author: Fezder
author_rank: Regular Contributor
timestamp: March 31, 2013, 06:15:25 pm
content: Quote from: Rodville on March 31, 2013, 06:12:18 pmfollowup? oo, gotta watch that. even if i would'nt understand half of it....

author: Erwin
author_rank: Newbie
timestamp: March 31, 2013, 09:58:36 pm
content: What about this? That does look broken.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 31, 2013, 10:40:59 pm
content: Quote from: tom66 on March 31, 2013, 10:49:17 amThrow in a Core i7 and some nice GPUs and you'll get all of those.

author: tom66
author_rank: Super Contributor
timestamp: March 31, 2013, 10:43:41 pm
content: Quote from: NiHaoMike on March 31, 2013, 10:40:59 pmHah... 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.

author: Monkeh
author_rank: Super Contributor
timestamp: March 31, 2013, 11:05:28 pm
content: Quote from: Erwin on March 31, 2013, 09:58:36 pm... there's nothing wrong there.

author: Erwin
author_rank: Newbie
timestamp: March 31, 2013, 11:24:20 pm
content: Quote from: Monkeh on March 31, 2013, 11:05:28 pmI 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.

author: k8tek
author_rank: Newbie
timestamp: April 01, 2013, 12:47:46 am
content: Nothing beats the old console CRTs.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 01, 2013, 01:55:22 am
content: Quote from: tom66 on March 31, 2013, 10:43:41 pmIt 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.

author: leno
author_rank: Newbie
timestamp: April 01, 2013, 03:10:50 am
content: This could be the the remotehttp://www.ebay.com.au/itm/Replacement-Remote-Control-for-Samsung-PS42S5H-/111004759569?pt=UK_AudioTVElectronics_Video_RemoteControls&hash=item19d8663611or one with a busted screen may be comes with a remote and u could swap the digital board to see if it fixes ithttp://www.ebay.com.au/itm/Samsung-42-Plasma-PS-42S5H-/221207079316?pt=AU_Televisions&hash=item3380f82994

author: adcurtin
author_rank: Contributor
timestamp: April 01, 2013, 07:08:47 am
content: 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.

author: tom66
author_rank: Super Contributor
timestamp: April 01, 2013, 08:11:20 am
content: 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.

author: hammil
author_rank: Regular Contributor
timestamp: April 01, 2013, 12:15:22 pm
content: Quote from: tom66 on April 01, 2013, 08:11:20 amThen 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.

author: kfitch42
author_rank: Frequent Contributor
timestamp: April 01, 2013, 12:17:21 pm
content: Quote from: NiHaoMike on April 01, 2013, 01:55:22 amI think that exists, it is called an iMac.

author: tom66
author_rank: Super Contributor
timestamp: April 01, 2013, 01:09:06 pm
content: Quote from: hammil on April 01, 2013, 12:15:22 pmWell yeah, but they cost more because they are for industry. I have a HTPC for all those smart features. Anyway, I don't buy much electronics new any more. At least manufacturers still make some dumb TVs but I wonder how long the trend will continue.

author: Erwin
author_rank: Newbie
timestamp: April 03, 2013, 09:29:33 pm
content: Any updates yet? Wondering if that possible issue I mentioned is really something or not.

author: M0BSW
author_rank: Frequent Contributor
timestamp: April 04, 2013, 06:37:32 pm
content: I no know nothing about plasma TV's and how they work, here's my question do they have a form of degaussing like normal crt TV's, I know they don't have the normal crt screen & it's I think it's chemical makes it work, but is there anything built into the electronics for colour patches.

author: tom66
author_rank: Super Contributor
timestamp: April 04, 2013, 06:57:01 pm
content: No degaussing necessary.The operation is very different from CRT TVs.For one, no high voltage (~20-30kV.) Only 200V. High, but not impossible to work with. Secondly, the display has memory, which means it stores an image on it and displays it as necessary. Thirdly, it is a digital display. Pixels are off or on, greyscale is created using 8 or more subfields of variable length (previously binary weighted 1, 2, 4, 8, etc but now using other weightings.) The phosphors are similar to that in CRTs.

author: M0BSW
author_rank: Frequent Contributor
timestamp: April 04, 2013, 07:13:29 pm
content: Quote from: tom66 on April 04, 2013, 06:57:01 pmCheers Tom , I really don't know how they work, think I'm going to need to read up on them, aren't they quite thirsty on power use, we are getting a NEW LCD tv, a monster 42,inch I think or bigger . it's my daughters choice, going to be hungon the wall apparently Panasonic, that was the only say I got in it, I enjoy my time more on the amateur radio so watch very little TV

author: tom66
author_rank: Super Contributor
timestamp: April 04, 2013, 07:27:03 pm
content: Quote from: M0BSW on April 04, 2013, 07:13:29 pmDefinitely quite power hungry. An LED 42" would use 40~90W, whereas a 42" 1080p plasma would use around 120~250W.

author: M0BSW
author_rank: Frequent Contributor
timestamp: April 04, 2013, 08:01:54 pm
content: Quote from: tom66 on April 04, 2013, 07:27:03 pmCricky Tom I'd have to cut down their viewing, now that's an idea, I can see LED TV's a so popular, our neighbour has one of those Samsung's without the remotes ,you just swipe your hand in front of it,, nothing but trouble, I think he's on his 3rd one.

author: tom66
author_rank: Super Contributor
timestamp: April 04, 2013, 08:25:45 pm
content: Samsung make very nice TVs to use and watch... but build quality is rubbish and reliability is worse than most.

author: Remy Brandt
author_rank: Newbie
timestamp: January 30, 2014, 08:52:31 pm
content: You mentioned,cosmic radiation. But that is near nothing at the moment you are watching that TV.Most is just transistor and resistor noise.

author: charlieb000
author_rank: Newbie
timestamp: June 25, 2014, 06:46:10 am
content: Hello there,I repaired my crappy plasma (an NEC). It also gained an input issue also. I strongly recommend you track the input chip for the tuner and other inputs. because that input obviously works and the others do not then it could be the input switcher - which is an opamp, in my case a LT1260cs. Either that or its not receiving a relevant signal - you put the blue screen on so we couldnt see if it actually did try to switch or if it is stuck on tuner.If you are completely desperate for a picture, connect the antanna input to an ole VHS VCR which typically has a video modulator inside (its own analog TV station - it does turn it off because it does make the other analog stations weaker - if we had them, so make sure the "VCR" light is lit) so you can get some use out of the screen.here is the repair process on my screen. As i say here i wasted the time on it because i intend on using it as a dumb load, or i may want the power supply for later use, hence the reason for fixing.http://www.avsforum.com/forum/167-plasma-flat-panel-displays/1491776-fixing-old-nec-px-33m3g.htmlGoing by the silence on this, the screen in question has probably been dismantled.---the cables on the side are 140 conductors each (when he lifted one off they were marked in 5's. the other seems to be 50 (says so on the lock, the board print groups by 10, not all seen)some of the funny named electolytics have the samsung logo so not all questionable - but OEM brand dont mean good quality (look at the PIONEER pc drives).