YPPD-J018E, YPPD-J018C, STK795-820, STK795-821 compatibility and credibility

From the mailbox:

QUESTION:
(posted under our listing advertising STK795-820 as an alternative to YPPD-J018C and YPPD-J018E)
 
Dear Coppell TV Repair,

How can you claim those chips will replace a YPPD-J018E and work properly ?

- mygoodiefinder

 

ANSWER:

Well, as far as claims go we can claim anything, which is pretty much how the market operates at this and probably any other point.

So, with all due respect, I think the question that you wanted to ass is

Do you know and how do you know if STK795-820 can substitute YPPD-J018E or YPPD-J018C?

Luckily that's an easy one to answer too.

Take your pick:

1. Because we use them ourselves since 2009. A publicly available and independent proof of that claim can be found for example here , here and many other listings. (note: those links may not survive in a long run as eBay is getting harder and harder to please...but that's another story)
   
   
2. Because we've sold hundreds of them to customers as can be seen here and people seem to be happy with them (a proof of which is the feedback ratio)
   
   
3. Because we have seen original LG boards with the same number coming with any of the above listed components; as any manufacturer knows it is a common problem to run out of a particular component and to use a substitute until your main supply chain covers for the delay.

All in all those should be sufficient.

If I think of more I'll add them in the future.

Now, there are a few things worth mentioning here such as the fact that we mostly use STK795-820. Not YPPD-J018C and not STK795-821 even though the later is arguably a more recent and updated version of STK795-820.

Well it just so happens that we've had some bad experiences with a few batches of YPPD-J018C  and STK795-821 and ended up using STK795-820.

I've personally heard all kinds of stories from other repair shops - that STK795-820 generates too much heat; that instead it is the STK795-821 that produces too much heat; that YPPD-J018C are the better ones, being original LG part used in LG boards; that the STKs are Chinese fakes; that the J018C are Chinese fakes.

As I've said I've heard pretty much all.

My take is that other people have run on other bad batches and as sure can be said about anything in the world there are simply bad batches.
Especially if they come from China and that's what everything comes these days (milk or chicken , anyone?)

So we stick with what works for us and we'll continue sticking to it until something forces us to look again.

On that topic I want to remind the readers that newer is not necessarily better. Many times in machines and electronics newer versions are simply stripped down releases of the original, i.e. an extra circuit or component with secondary, often preventive or noise-suppressing function, is being removed as it is not essential to the functionality while stripping it down in tens of thousands of produced units has a distinct impact over the cost.

Unrelated to the current topic, but related to the question at the beginning: salesmen have always made and will continue to make all kind of completely stupid claims while pushing to attract more buyers or convert a viewer to a buyer.

One of my favorites is from all TV chop-shops (eBay and elsewhere) who claim that a sustain board has come from a TV with broken screen, but it was tested and guaranteed to work.

Suck a lame lie!

Toshiba 50HP66 50" plasma, loud pop, screen went dim - what to do

Question: 

A friend of mine recommended you. i just bought a toshiba 50hp66 50" plasma. loud pop, screen went black. after sitting off for an hour turned it back on. everything works but is very light colored and dim. pictures seems to be clear, no lines,spots etc... not sure which board would cause a dim screen. thanks in advance.  Travis

Answer:

This is a known issue with Toshiba 50HP66 and a bunch of other TVs using the same display and supporting boards.

(in a plasma TV almost everything is about the display being used; same display in two different models means that bunch of other boards are also the same, namely the sustain boards, the buffer board(s) and the plasma display controller; the main board is different for different OEMs and that's about it. Oh well, the power board may also differ, but the differences would be very minimal, e.g. an extra 15V power needed by the main board).

Anyway, what goes bad with a pop is one of the sustain boards. Sometimes both, but most commonly just one of them at a time.

Here is how the TV looks at the back when you open it (click to get larger picture):

What usually goes bad is either the larger board with three heat sinks to the left of the TV (called YSUS board , or, sometimes Y-Main) or the one with two heat sinks at the right side of the TV (called ZSUS or sometimes X sustain).

Sometimes, but relatively rarely, it is the large board in the middle of the picture (and the TV) that goes bad  - that's the power board; if the TV is completely dead and has no front LED indication, no response to power button then the first thing to check is the power board.

Anyway, in your case it is mostly sure that it is either the YSUS or the ZSUS board that is bad.

And since you say you do have a faint, dark image on the display then it is most likely that it is the ZSUS board that has failed.

Here's a closer look at it:

 

Now, customers often ask how to make sure the board is bad before sending it.

They read around Internet and search for swollen capacitors , burn marks and other signs of a failure.

Well in case of those boards the truth is you don't normally see signs of a failure.

What fails is under the heat sink and above the board. There's simply no way for you to see it there, but for your eyes only I've blogged about the subject before so you can actually see what has happened there if you're curious:

http://blog.coppelltvrepair.com/2010/02/y-sustain-6870qyc004b-6871qyh039a.html

Sometimes the failure results in a short and that can be measured , but often times (as in your case) it results in an open circuit and that just can't be measured without applying power.

Which means the easiest way to test the board is to put it in a working TV to see if it will still be working.

And that's exactly what we do when we receive one of those for service.

If interested in using our service or servicing it yourself...here's a link for  you:

Toshiba 50HP66 repairs and modules from Coppell TV Repair

When 6871QYH039B fails, should buffers be replaced too? (same for 6871QYH039A, 6871QYH039B)

Question:

Hi. My concern is should I go ahead and get the Y-buffers too. Cant a bad buffer blow the new Y-sus? How can I check the buffers without replacing the Y-sus? Do you carry the buffers? Thanks, Geo.

Answer:

With this particular YSUS, an in fact with most sustain boards made by LG (at least in the 2004-2007 models) I would not worry about the buffers when a YSUS fails for several reasons:

 

First, the popular concept that when YSUS fails one should look for the buffers is most likely coming from the Samsung designs from the same time period. LG electrical design is similar and does not have the same failure characteristics as the Samsung boards.

In the Samsung cases it's the buffer board that fails first and damages the YSUS.

With LG, the sustain actually fails before the buffer and usually does not affect it.

Second, when the LG buffer ultimately fails (because that can happen too) it does not tend to damage the sustain. It is possible for it to happen, but it is rare.
 

Instead, when an LG plasma buffer board fails (e.g. in Toshiba 42HP66 or  50HP66) it will typically cause a vertical line as explained in this previous article.

As with any failure it is not guaranteed that it will happen that way. It's just the most common result.

 

So, in a nutshell, it's not worth worrying about the buffers at the time when you know the problem is in the sustain.

It's not bad to check them, but it would be unusual for them to have failed at the same time with the YSUS.

Dell W5001C power issues, sound without picture problem and some other thoughts

Below is a request from a potential customer and my response to it.

This time it is not the usual customer complains, I promise.

The email, I take it, points to an earlier post in this blog, where the issue is also mentioned...but I figured I'd post the question and the answer anyway.

After all other professionals deserve to know what we think about them...and maybe even that we tend to sometimes admit we might be wrong...

Question:  How much to send in what ever boards for you guys to fix?  I turn the power on, and it takes 3...4...5  8 mins for it to boot up.  Then the tv is fine for hours and hours.

The Caps look good, but like you said maybe they are out.  I read a few ppl that posted after they did the fix you told them they get no picture now but sound and high pitch sound.

So how much and what are the odds you can fix my issues.

Thanks,

Another DELL Suckka

Kevin

Answer:

First off, Dell has very little to do with all this.

Like most American brands these days it's just a hat over an Asian company. In this case - Samsung.

The few ppl who have picture but no sound have a completely different problem (probably this one), which is the actually the even more common issue with those TVs and is more expensive to fix too; it is completely unrelated to the delayed power on.

What you describe sounds 100% like bad capacitors. It may be the ones from the post, it may be different ones...it may even be capacitors not on the power board, but on the main board...because there are ones in both places and they actually even do the same things...so there's always chance that it may be the other ones that have gone bad...and there are quite a few of them too.

But, statistically speaking, you can't go wrong starting with the ones the article talks about.

I know that's what I'd do before investigating anything else.

Working in TV repair industry for a while made me rethink my opinion of doctors who tell you bunch of seemingly useless stuff to do whenever they see you.

I mean if you see 50:1 ratio of problems with certain syndromes it is only natural - a sign of intelligence, in fact - to expect that the every new case with such symptoms will carry the same cause and therefore be treated the same way...especially if there's no big hurt doing it anyway.

Seriously, doctors are maybe not such a morons after all :-)

Should I replace / repair one or both sustain boards in my plasma TV?

 Dear Coppelltvrepair,

I have a blown fuse on my YSUS board, but not on the ZSUS. Do they need to be replaced in pairs, or can we just fix the YSUS? Thanks!!

- tightwadcowboy1954

We get this question all the time and we give the answers all the time, so once and for all we'll post the answer here and just point people to it.

Right answer: It depends.


Short answer: Yes - service both.

Long answer: Read below.


What are sustain boards and what do they do?
 
Every plasma TV that we know has two sustain boards - Y-SUS and Z-SUS (also sometimes called X-SUS).

Below is a picture of a randomly picked plasma which shows their location, which is again the same in all plasma TVs that we have seen this far. You can click on the image to see it in full size.

Y-Sustain and Z-Sustain have very similar functions, but, as can be seen, the YSUS is a bit larger than the ZSUS. It also produces output that goes into what's called YSUS BUFFER board(s) which in turn output to the plasma display whereas the ZSUS outputs directly to the plasma display.

It is because the YSUS does a little more work than the ZSUS. Roughly said, while the ZSUS activates all display lines at once (thus affecting the whole display at the same time) the YSUS, with the help of the buffers, is able to activate (technically address) the individual lines on the display.

Other than that, though, they do pretty much the same thing.

The two boards work together on the display in order to produce proper images, however they do not need each other in order to function. In other words the function of one does not affect the function of the other.

They work on the display practically independently from one another, only in a fashion synchronized by another board, so that you get to see what you want to see.

Direct conclusion from the above is that with some exceptions

When one sustain board fails it does not affect functionality of the other.

In other words if your YSUS failed that should not and usually do not affect your ZSUS and the other way around.

The most notable exception that I can think of is when one of the boards takes power from the other and not directly from the power board. This is the case in some LG 50'' models where the ZSUS 6871QYH044 takes power through the YSUS 6871QYH039; when YSUS fails it may burn the fuse and thus cut ZSUS from power.

Technically, however, ZSUS' functionality is still not affected in this case - the board is functional, only the power to it is cut.

Which is to explain and underscore that functionality of one sustain is not affected by the other.

Still, it is affected by something completely different, which suggests

It may still be better to service or replace both sustain boards at the same time.

Here is what it is:

Sustain boards are the hardest working boards in plasma TVs. Many of them, especially those designed in the early plasma technology years - 2001 to 2005 - are improperly designed and/or improperly built so that they work at too high temperatures.

As you should know from your basic physics course matter expands when its temperature raises and shrinks when temperature lowers. 

The higher the temperature differences, the bigger the physical difference.

This cycle of expansion and shrinking , let's call it thermo-cycle, is also affecting other properties of the matter than its size. It also changes its electrical and mechanical properties.

Those changes are practically aging of the matter and, most simply put

Most plasma sustain boards have practically limited life

To summarize: because they work on too high temperatures, their expansion/shrinking is too drastic and that leads out to too limited life expressed in failures every several years.

Is it a design failure? Or is it simply badly built semiconductors?

Was it done on purpose? Or was it just another side of the wild competition leading to lower quality?

I won't discuss those here. But I'll return to the question at hand: 

What happens with your sustain boards during their life time?

Well, they wear out, that's what happens.

The example I like to give is two car tires on the road.

Road and friction do to car tires what marginal thermo-cycles do to semiconductors (and everything else actually).

So you've had two tires that have been working side by side for so long that they both got very worn out. You didn't see the treads, but if you were to look maybe you would have seen them.

And one sweet day one of your tires just couldn't take it anymore and blew. Just from wearing out.

Car tires - and semiconductors - are never really exactly the same, so they'd rarely wear out in the exact same way and burst out at the exact same time.

But you can make a very good guess as to the condition of your other tire or sustain when one of them bursts.

Granted,

sustain boards are NOT car tires after all

You don't risk your life or someone else's life  when you watch TV.

Often the second sustain board would fail fairly soon after the first - hours to days.

About equally often it may take weeks.

It would be unusual to take months, but it is not unheard of.

Hopefully you get the point.

This is also why it is better to have a board serviced than replaced with a used working board

Of course it is best to replace it with brand new one, but this is often prohibitively expensive or even impossible. I personally wouldn't advise anyone to spend $250 for a brand new sustain board on a 42'' or even 50'' plasma TV made in 2005 or so. It's flat out insane, first because TV prices dropped a lot since then and second because we know now that soon that TV is likely to need at least another board replaced. $500 for service of a TV that can be replaced for $600? Thanks, but no thanks!

Service, on the other hand, ensures (when properly done) that the power components will be replaced with new ones.

Replacement with a used board obtained from a chop-shop like Discount-Merchant, ShopJimmy or eBay is going to replace one used board with another used board...with very short life expectancy.

You do the math.

How to test STK795-518 YSUS IPM for defects

This article will tell you a few quick checks for the most common failures found in Sanyo's STK795-518 used  in YSUS board LJ92-01200A and a 50'' plasma sustain board (let me know the number if you have it!).

We at Coppell TV Repair do our best to protect ourselves and our customers from bad parts, but ultimately nobody would take care of the customer than the customer himself.
Of course by publishing such information we inevitably also continue to indicate our competitors some of which we are proud to see as subscribed followers of our blog.

For what it's worth, that's the nature of this business.

Competitors, feel free to copy this and post it on your sites...you are going to do it anyway, you might as well do it with our blessing.

Now back to the task at hand.

The tests described below are applicable with the IC on and off board. Of course we strongly recommend that you apply them before you solder any IC on the board - you'll save time and you'll also increase the odds of being able to return the IC back to the vendor with least worries.

Those tests are not complete in a sense that they do not guarantee that the IC will work properly.

But they clearly indicate if it is bad and while it's not guaranteed, we find that 99.9% of the time when an IC passes them it works good on a board.

It all boils down to detecting continuity (shorts) or low resistance (ohms) between certain pairs of pins on the module..

If you find one the STK795-518 is certainly bad.

The tests can be done with the IPM on or off the board.

Here's a picture of the pins of interest:

As you can see there are 4 points of interest - GND (Ground), Vs (supply power), SUS and ER, which are the two outputs for the sustain and energy recovery accordingly. Those two are shorted on the board, but on an actual IC are NOT connected to each other.

Here's the simple rule:

THERE MUST BE NO CONTINUITY (SHORT) BETWEEN ANY COMBINATION OF THOSE!

IF YOU FIND A SHORT THEN YOUR STK795-518 IS DEFECTIVE.

This is actually 100% correct for all other plasma IPM modules.

There are 4 inputs/outputs which result in 6 possible tests (Vs-GND, Vs-SUSout, Vs-ERout, GND-SUSout, GND-ERout, SUSout-ERout), but in reality two are the most common failures that we see in STK795-518:

1) Vs shorted to one of the two sustain outputs:

 

2) The other sustain output shorted to ground:

How to uninstall 6871QYH053B and compatible boards from 42'' plasma TV

People often ask me how to uninstall the YSUS board 6871QYH053B (or some of its compatible models - 6871QYH048B for example) from their 42'' plasma TV.

Coppell TV Repair services those boards and the question is natural considered we expect you to send us the board for repair.

This is a really quick tutorial that is board-independent and TV model independent.

It is important to say that while different board models do not have any differences in regards to dismantling procedure, the TV models may make it a bit different as to how do you get to the board.

Again, this short guide is aiming at all models and I will point out where differences are expected.

To uninstall the board, first lay the TV flat on the floor, face down.

Unscrew and remove the base, as most of the time it gets in the way. Sometimes it does not, but we usually remove it when we work on a TV.

After taking all the bolts of the cover (and sometimes ones that we shouldn't take out) and removing the cover we look at something like this:

On all plasma TVs that I have seen the YSUS is on the left and the ZSUS is on the right. They look differently in different makes and models, but they are always left and right and YSUS is always a bit bigger than ZSUS.

Otherwise they share a lot of functionality and, logically, appearance.

Anyway, the trick to pulling out the YSUS is usually getting access to the lower right corner of the board where there's a screw in the corner and - in this case - a very fragile flat ribbon cable connector.

To get to there, you often need to uninstall and move the whole central block assembly containing the main board:

In this case, there were two bolts on each side that were holding the assembly, plus three more on the bottom that were holding an L shaped metal supporting the assembly by tying it to the chassis.

In your case this may be slightly different and in some cases you may also need to remove the vertically standing support bar used for both wall mounting and construction support. At least we've done it a few times but most of the times - possibly always - you can get away without having to do that.

After all the bolts affixing the main board assembly are removed, you can simply pull it up and/or push it to the side:

As I said what you're aiming at is access to the lower right screw of the YSUS board and, of course, the fragile connector P8 just above it.

This is how the beast looks up-close:

Again, it is OK that your cable is white and ours is not. We're the pros, we can afford better cables, wink-wink.

The cable in your TV will likely be white and not orange-brownish as in our picture. Do not pay attention to the color and please do not call to ask if that is a sign of anything. It isn't.

To uninstall the cable, you need to flip the right side of the brown plastic covering the flex cable so that from horizontal it turns vertical. The hinges are at the ends on the left side and are extremely fragile.

I hear there are special tools that let you open it, but I am old school with fingernails and do it this way:

If you can't make a difference between the two pictures, look at how the brown cover is already flipped up on the second one.

The trick for me is to have relatively wide access of the force that pulls up and to also push a little bit inwards in addition to upwards.

Wide contact is necessary so that you actually make the whole length of the cover to wish to turn up. If you apply force only in one point in the middle the brown cover will likely bend and break the hinges.

So if you are using a screwdriver make sure you get one with wider tip.

A great idea is to use two fingers if you can do it - pointing and middle finger work great.

HP PL4260N suddenly lost picture - how to identify failed sustain boards

Synopsis: this article discusses the most popular failure in HP PL4260N (and the bunch of other TVs based on the same plasma display set by LG), the means to diagnose which board has failed and provides links for repairs / replacements for the failed boards.

Question:  I have an HP PL4260N plasma TV  (purchased 2006)  that has suddenly lost picture.  I don't know whether sound is still there since it is run through a home theater receiver.   I have taken the back off and none of the fuses are blown and there is no obvious bulging of any capacitors ( with one possible exception of a large 450v, 330 mf capacitor... it is so very slight that it may not be a bulge at all).  All fuses (there are 5) show continuity.  When the on switch is pressed it turns blue and then back to red.  No picture at all.

I have read your very interesting blogs but have found nothing specific to my Hp model... some say is was actually manufactured by either Samsung or LG.  I realize the information I'm giving you is sparse but from what I've read, I assume the failure of the Y an X boards as well as the power supply involves the failure of their fuses.... as mentioned, no failure noted.  Should I go ahead and replace the suspicious capacitor as the first step?  What can I do to determine the faulty board or combination of boards and what would each cost to repair.  Also, if a board tests OK by you, what would the charge be for the testing?

Answer.  Yes, this is likely a YSUS or a ZSUS board on your PL4260N.

(for those who do not know what YSUS and ZSUS are, here's a quick pictorial guide:)

A blown fuse is the most common and apparent indicator of a failed board, however sometimes a board can fail without blowing a fuse.

So while a blown fuse is a guarantee of a failure, the lack of a blown fuse is still not guarantee of anything.

Since your TV refuses to power on (going blue and then back to red) that would suggest the faulty board is shorted. When the power component on it has failed, a power semiconductor element there (one or more) have melted and has created a permanent (short) connection between power input and ground.

This is one of the possible outcomes of a power component failure and should not be taken for granted in all cases of a failure, but is still a very common one.

The same shortage is the reason why fuses blow in the first place. In your case, as we said, the power supply board has responded faster than the fuse and shut itself off.

Now when powering on it again detects the short before releasing full power voltage in that circuit and shuts off, which is why you see the TV going from blue back to red in a very short time.

When there is no burned fuse on either sustain board there are two major possibilities for a failure:

1) When the TV would not come on at all
That would indicate that a board has failed and shorted a major power line, but did not blow a fuse and as a result when TV is turned on, the shortage is detected by the power board and it automatically shuts itself down.

It is very easy to figure out the failed board since it prevents the TV from coming up: all you have to do is disconnect first one of the boards from power, say the YSUS board, and attempt to turn on the TV.
If the TV comes on and stays on (of course without anything on the screen) then the disconnected board was the one that was stopping it.

If the TV keeps on doing the same then connect the board back to power and disconnect the other one, then try to power on again.

If TV comes on this time then you've found your faulty board and if it still doesn't then the problem is most likely in neither of the sustain boards (although it is theoretically possible that both of them are bad).

Another simple way to find the failed board is to use DMM to measure resistance between Vs and GND pins on the power connector of the board. Zero or low (ohms) resistance in both directions indicate a failed board.
Please note that this is not the only possible short a board may develop, only the most common one.

2) When TV would come on with black screen or , sometimes, very dim, washed out screen
This is actually the more common failure than the above.
Dim and washed out image is most commonly caused by a failed ZSUS board.
If there is nothing on the screen, however, it could be either the YSUS or the ZSUS board that is bad (and very rarely both of them).

The easiest way to test which of the two may be bad is to let the TV run for 5-10 minutes (with dark screen) and then feel the heat sinks on both boards with your hand.

The one that is not hot is probably the faulty one.

If both are hot then the best thing to do is to send both of them for complete test in an actual working unit.

It is worth noting that a good number of times when the board fails it does not end up being short. It is still malfunctioning, but not necessarily short. Even more, sometimes it may have blown the fuse and still NOT be short. So if you replace the fuse you'd be able to power on all right, but still without an image or - sometimes - with a flashing light on the screen or other defects.

Once you figure our which board is bad - or if you can't figure it and need to check both - feel free to send them over to Coppell TV Repair (see section below) or, of course, any other vendor of your choice.

It is also worth noting that the same thing is going to happen on your other sustain board, so you may consider doing a service on both - one because you must and the other one in advance.

Here's a link to another article discussing the pros and cons of servicing one versus both sustain boards:
http://blog.coppelltvrepair.com/2011/05/should-i-replace-repair-one-or-both.html

UPDATE: here are a few tips on disconnecting the Y-sustain board hopefully without damages:
http://blog.coppelltvrepair.com/2011/03/how-to-uninstall-6871qyh053b-and.html

SENDING YOUR BOARD(S) TO US

We have separate offers for repair of the YSUS and ZSUS boards, however should you decide to do both of them simply send both together, that's all.

YSUS repair:
http://www.coppelltvrepair.com/p/164/1032298-hs-ysus-board-hp-pl4260n-repair-service

YSUS exchange:
http://www.coppelltvrepair.com/p/397/1032298-hs-ysus-for-hp-pl4260n-buy-now-then-return-your-old-board-to-get-credit

ZSUS repair:
http://www.coppelltvrepair.com/p/295/hp-pl4260n-zsus-board-repair-service-dark-image-bleeding-colors

Hope that was helpful!

See you soon!