Wednesday, October 3, 2012

Myths and misconceptions about (repairing) plasma and LCD TVs

A good deal - I guesstimate anywhere from 10% to 20% - from our support calls start with something that can be summarized this way: "My TV stopped working and I need to know if you have power board for it, becuase that's what is bad, right?"

Internet posts from DIY experts and self-promoting TV technichians add a great deal of confusion to almost any failure since almost everyone who was successful at their first DIY repair tends to assume this is a common problem for the TV and describes both the symptoms and the solution with the capacity of an experienced technicians who has seen and done it all.

Which is hardly ever close to the truth in the big picture of common failures and the various post-failure symptoms they cause.

In this article I will review a few popular misconceptions that we at Coppell TV Repair are encountering pretty much on a daily basis.


1) If TV does not start up the problem is in the power board

As said earlier this is the most common confusion we are seeing among first time callers. They often cite Internet as a source for their self-diagnostic and at least half the time they are wrong.

I have personally seen and corrected many posts at Fixya where someone considering themselves an expert - or simply someone willing to help without realizing they're doing exactly the opposite - authoratively advises someone with a question that the problem is in their power board.
Sometimes they may be right, of course.

But very often they wouldn't.

The first and most important piece of information is always the specific TV model as the issue is first and foremost specific to a particular board in that model.
(And this is why our diagnostic service starts with it.)

Next , at least for me, is the display technology as it has a great impact over the architecture and risks associated with the power board.

Plasma TVs, for example, have more powerful and more complex power boards, which feature more protection mechanisms; in addition, plasma TVs are prone to failures in other modules - specifically the sustain boards - which are, in a way, also power boards fed from the main power board and a TV would often refuse to start if a sustain board has failed and shorted.

Moral: Do not assume what's wrong with the TV just because someone said so, unless you know that someone is good at what they say.

2) If TV doesn't work replace the capacitors!

That's probably the second most widesread myth about failures.

Oh yes - bad capacitors can cause tons of problems. In certain modes and batches of those models.

They'll be OK on others and they will be the last issue to develop on many many other TVs.

For example the infamous Dell W4201C has an issue with two capacitors in the power board, but only in some TVs; in others, different capacitors were used and the power boards go for years and years, giving way to the guaranteed problem with the failing buffers and Y-Main board.

Or say the Sanyo DP46819 or Sanyo DP52449 and others Sanyos from the same family...the main board is way more likely to develop a problem than the power board and it won't be capacitors either.

Being still popular, the capacitors replacement business have created companies offering just a bag with all electrolytic capacitors from a certain board and proudly labeling it "repair kit".
I've seen a few such listings on eBay, for example this one and this one, which are funny, because they offer to resolve a problem, which practically does not exist.

Power board BN44-00161A has a high failure ratio and to my amusement there was a popular vendor on eBay who was selling for a long time a "repair kit" of 2 capacitors and 4 FETs, a combination which I have never, in hundreds of repaired boards, seen needed together, but definitely falling short of covering the most common failure on that board. It took them two years before they started selling the right kit!

Moral: Repair kits are like drugs - there's tons of them out there and everyone's claiming theirs is the best, but ultimately the only good repair kit is the one that targets your particular problem. Make sure to find detailed description of the problem they target and verify they come from a vendor who knows about TV repairs and doesn't just read Internet like you do :-)

3) Plasma TVs should not be laid horizontally

I don't know why people have that idea. When I asked a few times I got "well somehow I just thought so".

Plasma TVs have gas in their displays and gas, being intert, does not care if it is horizontally or vertically oriented in space.

You can do keep or service your plasma any way you want.

One of the benefits of servicing it horizontally is that it's harder to lose a metal bolt or screw down the boards.

Moral: If you lose a screw between the boards turn your plasma upside down and shake hard until you get your stuff back on the floor. It's fun!


4) Buying used boards from chop shops is a good idea

Well that one is kind of true...sometimes.

It really depends on the board and the failure it gets.

Some boards - particularily plasma TV buffer boards and sustain boards - are known to age with time, in fact fairly fast - 3,4,5 years...and they just fail at the end.

When a chop-shop like ShopJimmy , DiscountMerchant or any other one really, buys tons of liquidated TVs, take the boards out and sells them, they have no way of knowng how long did those boards work before getting to them.

Frankly, I dare say most of them do not know (or have not been knowing for a very long time) that the parts they were selling were fast disposables and having arrived from a used TV they have a very short life.

Of course for many other cases chop-shops are not only useful, but often only available alternative.

Moral: New is always best and sometimes repaired is definitely better than used.

5) It is best to buy replacement boards from the same brand than others

Again, it depends a great deal. Some boards you can only buy from that particular brand.

More often than not, though, you can buy the same board from a completely different brand of a TV and use it at 100%.

This is particularily true for plasma TVs where there are several major plasma display technology, which develop practically the whole plasma-related part of the television - specifically the display and the boards that make it show picture - and license it to the rest, who use their own main boards, menus, internet connection etc. stuff that is secondary to the display itself.

As of 2012 easily 90% of all plasma TVs in USA - that's over 50 brands - are made by only 3 companies: LG, Samsung and Panasonic. Fuji and Hitachi have some market, but I don't think it is of significance (except for people needing Hitachi buffer boards I guess).

Which mean that the plasma display and sustain boards in HP PL4260N are practically the same as the display and sustain boards in Viore PDP42V18HA. They work the same, fail the same and can be serviced the same.

Oh sure, HP is giving the boards different name so that customers get back and buy the same boards from HP - usually for more - but it's still the same board.

Moral: Do not buy from Viore unless you know what you're doing. HP has the same LG BS, but at least it gives you the impression of a higher quality.



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