Wednesday, August 17, 2016

Fix for RCA L46WD22 LCD TV without audio or having intermittent sound / audio

This is an old TV, but in my opinion well built one that will likely outlast great many of the TVs manufactured in recent years bare one silly defect in a fuse.

Hope this will save a good product from the dump and save someone a few hundred dollars:

Any 1A fuse will do the job, we just used a pico fuse we had handy.

If you need it you can get one at

Friday, June 24, 2016

Power restored at Coppell TV Repair service facility

Power was finally restored on Thursday evening at our facility.

We will be working around the clock to catch up with orders.

We estimate that it would take at at least a week and due to additional load factors it may as well stretch between 2 and 3 weeks.

We strongly recommend that you avoid calling us on the phone for most of July as we will be focusing on repair services rather than phone support, which happens to be quite inefficient anyway.

If you have an open service request already then the best way to contact us (and the fastest way to get informative response) will be through the service request thread available in "Service requests" under "My Account" at .

If you have not opened a service request then the best way to contact us would be via the "Contact us" link at the site.

We apologize for the inconvenience.

P.S. Special thanks to Electric Pros, Inc. and their owner Justin Klump for standing up and delivering what an average pool of about 10 other electrical companies we contacted failed to deliver! He was there within minutes on Monday and he delivered on every single promise he made. Kudos!

Monday, June 20, 2016

Service disruption due to major power outage at CTVR facility

This is a brief update to report that we are experiencing a major power outage caused by a driver losing control of his vehicle and driving over the power transformer supplying power to our and a neighbor building.

The incident has happened early morning on Monday June 20th 2016.

There is no power, no cooling, no Internet and - mostly - no phones at the site.

This will continue for at least a few days. It is not sure for how many exactly and it depends on forces beyond our immediate control such as local electric provider and electric service companies, possibly the police, insurance companies etc.

During the downtime we will NOT be able to work on any service jobs.

We will do our best to ship ordered parts and modules, but there will be delay with those too as we will have to be printing shipping labels in other places, then going to pick up modules from the main building etc.

Our site and email are for now fully functional.

Anyone who has sent their module(s) for repair and does not want to wait can have them shipped back the usual way for the sole cost of the return shipping, just as if we had failed to repair them in a timely manner.

We sincerely apologize for the inconvenience and will be providing update as soon as we know more.

Wednesday, April 27, 2016

Panasonic TC-P55ST30 7 blinks help and repair SC TNPA5351 and buffers

Just finished uploading a video on troubleshooting Panasonic TC-P55ST30 plasma TV that doesn't want to start and blinking 7 times on the front LED.

It was actually broken up in 3 parts you can find on YouTube:

Troubleshooting Panasonic  TC-P55ST30 part 1:

Troubleshooting Panasonic  TC-P55ST30 part 2:

Troubleshooting Panasonic  TC-P55ST30 part 3:

Those are not a complete DIY videos and do not show you how to actually do the replacement and repair parts; they are focused more on diagnosing the problem.

We haven't activated the corresponding repair services and repair kits at the site yet, but chances are by the time you hit this posting we already would have had it done. (is that a proper tense?)

Those should help you find them:

Now, I would like to summarize the videos that way:

1) To troubleshoot a TV you need a multimeter. It doesn't have to be a nice Fluke, a generic $30 device would do 99% of the time.

It is worth spending some time watching YouTube videos on how to measure voltage and resistance with the device.
For sake of finding shorts and generally troubleshooting resistance (or continuity, which is the physically and mathematically opposite of resistance) is usually measured using the DIODE symbol on the device's dial for reasons you can find explained elsewhere.

2) You need to take off the back cover of the TV. Some TVs allow it to be taken while the unit is on its feet/pedestal, others require that the pedestal is taken out and the unit is laid flat.
It is quite OK to lay a plasma TV flat on a table.

3) If you see lots of dust in a TV (or any other device) take it out and suck it or blow it out of it. Doing that earlier is better than doing it later when you've picked and / or inhaled large portions of it.
Do as we say , not as we do in this video :-)

4) Most commonly failing power components in plasma TVs are transistors and diodes.
Transistors have 3 electrically different legs and diodes have 2 even though it is possible for a particular component that is a diode to have 3 legs and look like a transistor; this would be when inside there are 2 diodes with one common electrode or simply two of the legs would be the same electrode.
On boards didodes are often marked with prefix D followed by a number while transistors are often marked with prefix Q followed by a number. D101 is a diode, Q101 is a transistor.

5) You check for defective diodes and transistors by testing each possible combination of electrodes for low resistance near to 0. A true failure would have the same low resistance in both direction, e.g. by swapping the places of the meter's probes you should get the same low reading.
Low reading in only ONE direction is usually indication for a GOOD device.

The separation between diodes and transistors is only important for the sake of knowing that in some cases you will find "shorted" electrodes, that are such by design - namely in diodes made with 3 electrodes.

6) Two things to watch for when looking for shorted components:

First, often times components are in parallel; one shorted component may make others appear shorted as well. Which means the first component you find shorted is not necessarily the actually bad one.

And second, sometimes low resistance can be found between two electrodes of a power component by design; this is fairly common with transistors in particular and easily recognizable once you establish the pattern, which is that such resistances have "rounded" values of say 15 or 20 ohm, which are hard to achieve my a failure (not impossible though!) and, most importantly, can be easily tracked to a resistor located nearby.

7) Not just SMD components fail. Check the ones on the heat sinks as well.

In addition, not only components included in repair kits sold by SJ and others fail. Many times companies sell you repair kits that were not even based on actual experience repairing boards.
Do not trust that if you buy a repair kit from SJ or even CTVR it will have all the parts you need!
But naturally I think it stands to reason to trust companies who offer repair services in addition to repair kits.

8) Transistors are sometimes organized in groups of 2, 3 or more working in parallel (one particular electrode labeled G leg is usually connected to the other G-s via small resistors while the other electrodes are directly electrically connected to the same electrodes from the other components in the group).
Determining which one of those has failed is subject of another article for sake of space, but it is a good idea to replace all of them when one fails.
It is not a must in most cases we've seen, but in some cases it is.
For Panasonic TC-P55ST30 it doesn't seem to be, but we still do it.

9) We've seen different failures on different boards; the video identifies the components we've seen fail.

You can get a repair kit from us or send the board for repair if you wish.

10) When the sustain board fails a buffer board may or may not fail along with it.

When it fails it is usually, but not necessarily the top (SU) buffer board.

The videos show you how to test for failure (short) on a buffer board and how to identify the faulty IC.

The method shown is 99% reliable meaning it leaves about 1% of the times when the board would be bad, but the shown check may not reveal it. The devil is in the details, right?

You can buy the ICs for the buffer board repair or send them to us to have them repaired and tested.

Hope this helps!

Vizio M470NV main board 3647-0302-0150 repair service available

I am happy to announce Coppell TV Repair LLC now offers repair service for the main board 3647-0302-0150 found in Vizio M470NV.

We also offer a board sale with trade-in option, but knowing how people tend to either not return old duds or return ones that have been badly tampered or - let's be honest - in some cases return duds that are perfectly intact and we still fail to repair - I wouldn't be surprised if we run out of working boards as well.

Just for the record, in order for us to announce a repair service it means we've been successful repairing a few and have typically seen at least two different issues; of course we are fully aware there's probably a whole lot more we haven't seen yet.

That is one of the reasons we do not promise success for any of our repairs (although for some we've done so many and have so many duds at the end of their life cycle we actually can promise a working board back, even if it means repairing and returning one of those old duds; then again, at this point of the life cycle people usually do not rely to repairs, but just buy cheap working boards off eBay..which is not always wise).

It is also one of the reasons why we do not charge upfront for any repair at .

A failed Vizio M470NV can cause loss of HDMI ports, loss of audio or video or TV that is totally dead, stuck to orange front LED or forever blinking and possibly others.

We also offer the flash memory IC (often referred to as EEPROM) for this and other Vizio models.

Friday, April 22, 2016

Vizio XVT553SV totally dead or HDMI ports not working

Lately we've been doing a lot of Vizio power supply and main board repairs.

As you may know by now the Vizio  TV brand is almost exclusively handled by Sharp and a lot of problems are common for their TVs since they follow the same design and production pattern and transfer the same design and production defects among different models.

One common issue we see is TVs failing to power or starting up with some issues such as HDMI ports not working or the audio output being either too quiet or missing at all.

We started offering the flash memory ICs for some Vizio models as well as repair services for the boards:

Friday, October 9, 2015

Why Y-Main and buffer boards should NOT always be replaced together

In a daily language "experts" are usually people who do something more intense and, preferably, do it for living as opposed to as a hobby or on the side.

"Specialist" is a bit better word in that context and frankly I do not want to go down to semantics as much as I'd like to separate people who develop extensive expertise in a particular area versus all others.

Without being top notch I consider myself an expert in plasma , LCD and LED TV repair due to the fact that i do it a lot and , if anything, my experience and guessing would likely be better than that of an average customer even if I happen not to be the brightest of service engineers out there.

All that said, I am often reminded how bad an expert advice can be.

A quick illustration is a blog article I came upon today, which explains why is it better to replace a plasma sustain board along with buffer boards.

The contents of the article may change after my post, so I'll copy a snippet here without author's permission. I looked for place to comment under the article to tell them what I am telling you, but there was no option to leave comments , so I am instead doing it here.

"This is actually a fairly common problem amongst Plasma TV's. The Y-Sustain Board often times go kaput and you run into the problem of "no picture but still having sound". Everything else seems to work like volume control, changing the channels, and even changing the input from one to next. No problem, you think to yourself. Just replace the Y-Sustain Board and you should be good to go, right? Hold on there, cowboy. Before you go and do that, understand for a moment that Plasma TV's, unlike LCD TV's and LED TV's, is a different type of TV technology and thus, the way it operates is also different. If and when "a part goes out," it works in a domino effect. In other words, when one board goes out, it often times takes out another board with it. 

In a Samsung HPT5054, it uses this Y-Sustain and Buffer Board set: LJ92-01490A & LJ92-01491A & LJ92-1492A. Now, inside your TV, the direction of electrical current travels from left to right and when this set is inside your TV, from where you stand with the base of the "TV Stand opening" facing towards you, it would be from the "bottom up" that the electrical current travels. And in this particular TV model, usually the "short" comes from the lower buffer board (LJ92-01492A) that ends up blowing out the Y-Sustain Board. In other words, when the lower buffer board goes bad, it usually takes out the Y-Sustain Board along with it. And before you go jumping the gun and concluding that maybe it's prudent to replace the Y-Sustain Board and just the lower buffer board without also replacing the upper buffer board as well, this is actually not a good idea. Why? Because if the lower buffer board goes bad and takes out the Y-Sustain Board along with it, it is just a matter of time before the upper board goes bad. And then you run into the same problem except this time, it will be the upper buffer board blowing out the Y-Sustain Board. In this case, it's a lot like how your mechanic recommends that when you replace your tires or shocks and/or strut assemblies, that they should be replaced in pairs, rather than individually because of the same rationale: when one goes bad, it's highly probable that the other one is on its way out even though it appears to the naked eye that nothing seems to be wrong with it. And if nothing else, replacing the Y-Sustain Board together with the Buffer Boards will sufficiently eliminate the possibility that the short was coming from the upper buffer board thus minimizing the chances that you would end up blowing out one of the two working boards that you just bought. Ultimately, it saves you time and money to replace them together as a set rather than replacing two of the three only to have one of the old boards blow out on you and taking out one of the two perfectly good board you had just bought a week ago. And these Y-Sustain Boards don't come cheap nor are they easy to find."

While there is definitely some truth to the above, there is also a fair amount of errors and misconception resulting, at the end, in an incomplete at best, and more rightfully misleading conclusion and recommendations.

Here's why:

1) The article builds a case based on one example and fails to review everyday practice for other possibilities.

Samsung HP-T5054 does have a tendency of blowing a buffer board and taking down the Y-Main board as a result, that is correct.

However I can list tens of TVs - practically all Hitachi models I know and most of the LG based ones as well - where this is NOT the case.

HP PL5060N is a 50'' plasma from about the same time when Samsung HP-T5054 was made. It tends to blow the YSUS and the ZSUS boards however rarely ever the buffer boards are affected.
And the buffer boards are practically never the source of the YSUS failure.

So the case of having to replace all 3 boards together goes down the drain from the sake of cost efficiency and even pure technical requirements.

In case of the Hitachi plasma TVs from the same time frame, buffer boards tend to fail a lot - kind of like with Samsung - but they rarely ever affect the sustain board. 1 in 100 or something to that extent.

We highly recommend that people do not replace the sustain board simply because it is not needed.

In short: Y-Main and buffer boards SHOULD NOT always be replaced together.

2) The article talks about the lower buffer board failing on HP-T5054 and specifies it as LJ92-01492A.

That is flat our wrong.

We have about 200 lower buffers L92-01492A available here, result of customers replacing the set of buffers with new ones.

The lower buffer rarely ever fails!

What is the conclusion?

Well, whoever wrote that article is not really a TV service technician. No offense meant.

For my two cents whoever composed the article is fairly intelligent as it is well written (well interpreted from other sources is my exact opinion) and it improvises a bit over the original.

But it lacks what it needs most, which is first hand experience and proper application of logic specific to the issue.

I do not mean to offend the author or the other company in any way.

I want to make a point that one should not believe everything they get from what can be perceived as an expert in a certain area.

That includes our own advices, of course :-)

Take any way you want.