4H.V1838.401 inverter hacking for Insignia NS-LCD37 LCD TV

This is a quick post for all the poor suckers who are trying to find 4H.V1838.401/D for a reasonable price.

I know how it feels, I was one of them myself when I bought a malfunctioning Insignia NS-LCD37 for $25 and diagnosed it with band inverter.

Well, at the time of writing this there weren't any good replacements to be found, not for a decent price anyway.

You could buy the transformers on eBay for $25 per piece, but I would have needed at least two PLUS at least two FETs that I found shorted and God only knows what else. That's easily $60, not to mention the FETs weren't available anywhere either and I would have to find and use substitutes...

This was easily a bad proposition so I set out to searching a replacement rather than repairing the inverter. You don't expect to pay more than $60 for a 37'' LCD inverter anyway...at least I don't and you shouldn't either.

In fact, I paid even less since I happened to have one handy.

Only it wasn't 4H.V1838.401/D.

It was 4H.V1448.481/C1 used in the next Insignia model, NS-LCD37-09.

Which is a totally different beast altogether, but that's another story.

The point is, while not an exact match, it is widely available, cheap and does the job!
What more could you want?!

Ah, pictures...right:


Here are the two inverters next to each other:

The first problem, as you will see, is that the connectors for the CCFL wires are different sizes:

This is an easy problem if you use good cutters. Just cut in half all connectors, including the one for the common ground which is at the corner of the board:

It's really as simple as that!

The next problem you'll encounter is that the new board is slightly larger than the original and doesn't fit the borders made by the little metal plates at the two ends.
I just bent those a few times until they broke and then put tape on top to make sure they won't short:

The great news is the main cable doesn't require any changes at all, it just goes straight in:

Next, of course, you'll need to tweak a bit the metal shield (if you opt to install it at all) so that it can do some decent covering and allows for fastening with bolts. A little tweaking with pliers goes a long way:

Finally, you won't be able to use most of the fastening bolts, but you should be able to use at least three, which is more than sufficient for steady positioning.

I didn't take a picture of the working TV since it sold and went out before I could make that extra shot.

And if you wonder how did I know all that in the first place...well, that's just how I am.

Modesty comes first, of course.

He said, I said, but he said and then I said...a look at the facts again

This post is a response to a buyer's review on eBay that we blamed everything but our own parts for his problems.

I've said it before and I'll repeat once again that people take the freedom of speech waaaay to far.

So instead of exercising in a free speech like many customers tend to do I'll yet again refer to the actual fact as they can be verified with an independent party, in this case - the eBay messaging:

You judge for yourself.

Customer review:
Went bad. Seller Blamed everything but his part. Ive repaired tv's for 10 years

 (author's note: why do so many people write "tv's" as opposed to "TVs"? Is it really incorrect as I think it is or is it just me? Not picking on this particular buyer, I often see it written that way especially by customers claiming to be 10 or more years in the business. Either English has a set of rules that I don't know of or...well, anyway, back to the point...)

Customer correspondence as fetched from the eBay history:

From: mainstreetpc
To: coppelltvrepair
Subject: Other: mainstreetpc sent a message about 6871QZH056B 6870QZH004B ZSUS BOARD *** REPAIR KIT *** #110623320783
Sent Date: Jul-23-11 09:28:53 PDT

Dear coppelltvrepair, Hi, I just wanted to let you know that this repair kit worked for about 2 days after it was installed and then blew again. Thanks Micky

---

 

Dear mainstreetpc, It does happen sometimes. Sometimes it's because of the IC in the kit - it may be just bad. People tend to presume this as the only possible reason. Sometimes it's the way it is being installed. I know because I've done hundreds of these myself. How do you apply the heat transfer compound. How do you fasten and what bolts do you use to fasten the heat sink. How do you solder. Sometimes it's other components on the board that were hit during the initial shock when the first IC failed or just components (particularily the second FET) that are so worn out they just give up and damage the IPM in the aftermath of their own failure. I've seen that too and I've seen it enough times to be certain it's a failure cause on its own that has nothing to do with the IPM. And sometimes - quite often actually after a few days pass with the baord working - it's actually the OTHER sustain board that fails and people call us and tell us that the one we repaired for them failed. I know that for a fact too since we do lots of those repairs and you can't really argue with numbers. So yes, it can be any of the above. if I had a firm way knowing which one it was I'd told you in advance and if I knew an IC would fail I would not have sold it. What would you do in my place, with so many possibilities and no engineering strict way to narrow down and avoid the problem? - coppelltvrepair

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 :-)

PHILIPS 37PF9431D dead, power board 310432838621 not producing output voltage

Coppell TV Repair for long offers a repair service for the above mentioned power board, but today I've got a board with a problem that I have not seen before so I decided to share it so that those blog followers who wouldn't anyway pay for a service at least get a chance of doing it right by themselves :-)


Symptom: When connected to power, the board clicks periodically about once every second - not a relay click, but an electric click as of a toroid on overdrive only more quite and nicer. Like it's trying to start and failing.

Problem: it turned out transistor 7006 had failed. Drain-Source was shorted and so the transistor had to be replaced. This is the beast in reference:

It is STP15NK50ZFP SuperMESH MOSFET  - 500V / 14A - and since we couldn't find one handy we used a substitute replacement.

Here is how it looked after the replacement:

Note the insulation barrier behind the replacement - if you do something like that you will need to have one too since the original is in plastic TO-220 corpus whereas the replacement is in TO-247 has metal back electrically connected to the drain (or source, whatever).

We checked for other damages on the board and when we couldn't find any we connected to power and voila, it worked like a charm!

If you happen to have the same problem and can't find the appropriate replacement, below is a chance to get what we used at what we call reasonable price (especially considering you've got the whole solution laid in front of you):

How to solve support problems and avoid alienating vendors

The following is an unchanged message from our mailbox:

Dear Seller!
I'm running respected and responsible Business, where I can't take "used" or "rebuilt" IC chips(what is complete nonsence) for my Customer's repair jobs! Therefore, I need 2 chips replaced(mandatory) for the new ones! Not the way you treat my entity! One IC was brand new and legidemate, second one was used, with traces of "chiseling" out of heat sink and puncture marks. Still, I showed those 2 to my Customer, before instalationin his Y-sustainer module. He, also noticed that second one was "used". He agreed to try them both, as long as they work in tandem for a while. Yes, those 2 worked for a duration of 10 minutes with TV set completely operable. Then, of course the "used one" gave up with a click and the board went inoperable. You Must know, I can't replace just one IC, but both of the at the time! Why didn't you send me 2 new ones from the beginning? thinking: asshole will eat a s...t! Just get back you reputation, before it's too late, and send me 2 NEW ones now!

- algre1

The author is making a number of mistakes that I have come to realize over time I myself do when being in similar situation. Affected, I point all my energy towards a stupid/lame/idiotic counterpart - be it a telecom, bank or my local HOA - and then wonder why not only it didn't solve my problem, but often actually made it worse.

Over time, I learned that mistakes happen everywhere and I can't stop that from happening. I can only handle it in a way that doesn't disrupt my lifestyle significantly and helps me walk out faster and easier , even if I can't resolve it to the best of my liking.

So here it is, hoping it will help a poor customer avoid having to send an email like the above and maybe thinking (certainly incorrectly!) that they've "squared" the stupid/lame/idiotic vendor right on the spot:

1. Keep your cool!
When emotionally lifted, one tends to do a lot of things that only damage their own position - using bad language (never mind bad grammar), mixing facts and assumptions, being overly demanding in a situation that requires diplomacy to solve, taking offensive stand and thus causing anger in response...and God knows only what else.

Napoleon is said to have counted to 10 before giving a response to anything that angered him.

Think you are better than Napoleon?

2. Stick to the facts, not claims or assumptions

For example, claiming that you "are running a respected and reasonable Business" is fine, unless trying to impress it on someone who has a public record of doing just that (say over 2000 eBay customers with over 99% positive ratings) and you actually do not. You may be a respected and reasonable Business, but with a public profile of 7 transactions there is nothing behind your claim to back it up.
That matters to people.

Even worse is wearing your vendor's hat and trying to think on their behalf like illustrated above: " thinking: asshole will eat a s...t!". 

Not everyone thinks as you think. Some of us even have a different vocabulary altogether!

And there are always at least two completely different explanations to everything that may have happened...looking for them rather than wearing the opposite party's hat and continuing to build to your own position is not going to help you.

3.  Communicate, do not demand

A direct consequence from the fact that there are at least two completely different explanations to every problem is that it is theoretically possible for the problem to have been in you in the first place. 

Whether you like to admit it or not it is always a possibility.

This is not the best example for it since it is likely that customer above was right that one of the ICs they received may have been bad, but I've blogged before about how people tend to make incorrect conclusions only to justify their own thesis.

In either case, if you want to achieve optimal result you'll be better off working under the assumption that a problem may have been caused by either side.

Certainly better than to take a one-sided stand and alienate the very people you're trying to work out a solution for yourself with.

4.  Take responsibility for your own actions

If you received something - in this case an IC - that you consider bad, then why did not act immediately and did not call the vendor?! Why instead you asked your own customer (?!) what to do - if he knew he would not have been your customer to start with.

Perhaps the following in the original listing somehow pushed you off your way:

"Please make sure to test the IC you receive before you put it on a board! We try our best to pre-screen them here and catch some problems, but ultimately you will help yourself and help us if you run a few quick checks before you spend time soldering the IC on the board."

(complete listing can be found at http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110587861804&ssPageName=ADME:X:AAQ:US:1123 )

Frankly, I think most of the customer's anger comes from the fact that they did not listen to the advice, took an action against their better judgement and are now facing the consequences of that very own action.

Granted, I'd be pissed off too when I receive something that's not what it is supposed to be, but if I try and use it against the warning and it naturally fails me I am rather certain I'd be equally mad at the vendor and myself for allowing to get into such a situation in the first place.

5. Recognize the simple fact that problems happen everywhereNothing is perfect and problems happen all the time. In any business, in any activity.
If you think your own business is perfect perhaps the first thing to do is force yourself to realize that it isn't.

Nothing is.

When a Bad Thing happens you're way better off asking yourself what's the optimal way to fix it than who is to blame, because often there is nobody actually to blame.

You may have received a bad part, but that doesn't mean your vendor put it there on purpose.

Working under that assumption is as wrong as claiming your Business is very respectable when there certainly are customers - if you are any Business at all - who surely don't think so high of you. There always are.

We've got the same blames from customers who received perfectly looking ICs. They weren't picking on the look, they were just complaining that the parts burst as soon as you power them on.

Sometimes they would have been correct and the parts would have indeed been bad and other times - without a doubt since we do repairs too - it would be something else on the board that would cause it.

Either way, building up a conspiracy theory where the vendor is trying to cheat on you - YOU of all! - is flat out immature, unless you've already given that vendor something to cause them cast trouble upon you.

As almost always, there's a simple and efficient explanation for the trouble, which does not at all require drama and conflict: there may have been a faulty product and vendor may have overlooked it. it's only normal and most vendors actually actively warn you for such a possibility as indicated above:

"Please make sure to test the IC you receive before you put it on a board! We try our best to pre-screen them here and catch some problems, but ultimately you will help yourself and help us if you run a few quick checks before you spend time soldering the IC on the board."

CONCLUSION

Your own day and the day of people around you would be so much better if you manage to stay cool and try to resolve a problem working with someone rather than trying to take a command and enforce your view and solution on others!


Sometimes you may get temporarily what you look for, but with this attitude and approach you're certain to ruin your life in the long run. 

It's a vicious cycle and it gets worse and worse as you keep discovering more and more enemies as the world inevitably hits you with more and more problems.

I guess that's why Vicodine and drinking are gaining traction all the time :-)

Isn't it so much easier to just say 

Hello, I have a problem with the parts I received from you. One of them looks like it has been used, can I please send it back for exchange/refund as per your own policy?

Of course not everyone is smart/brave/strong enough for a two-liner like that.

Luckily, most of the buyers still are and that is a fact, not a belief.

If it wasn't we wouldn't have been in business.

To set the record straight, here is the response I sent to the above letter:

"You know, I believe your story and I am sorry to hear about your troubles.

What I will do is assume that the problem is on our end, apologize for your experience and give you 100% refund on your order.

I will not offer you working parts for two reasons: first, because the original pair that you had received has come from the same box that everyone else receives parts from; you don't seem to believe that story and it's your right, but I happen to be in the position to operate based on facts, not beliefs, so if anything I certainly can make a decision easier than you do. We may not have checked the IC, that's completely possible, but that's about it and to make sure it won't happen again I am just giving you the opportunity to choose someone who can do better job for you.

Second, I just can't accept staying in a business with someone who can treat me the way you do.
Service repairs business is based on negative experiences and is tough enough as it is; inability to behave in the face of yet another problem is more than a strong indication for me to want off.

Not sure it will get through properly, but in a nutshell that's what it is: we are sorry if we have made a mistake, but those mistakes do happen, they are not purposeful and we are handling them the best we can.

In this case, we will take the complete loss and we will also take the possibility of you deciding it's all our fault and making sure we get our negative coverage for it.

We can't and won't do anything to stop you from doing that.

We just make sure that we've done the best we could for a customer and then for us to stay out of future trouble.

- coppelltvrepair"

I would not be surprised if case develops further, but at this point the only thing I really wished to say was that I am always sorry seeing how the concept of "competition" actually leads to spoiling customers by being forced to give them anything they want or else.

In long run it works against those very customers and this is something that every American is now feeling and is about to feel much more as the economic crisis unfolds further.

AKAI LCT3201AD LCT3285TA does not power up - fix power board MLT169A MLT169B

Dec 2012 update:
You can now buy the repair kit or have your power board repaired through our web store.

This is yet another classic in the bad capacitors department, so without further delay here is all you need:

SYMPTOMS may vary since all caps on the board can go bad and it's impossible to know which go bad before which. On that last board shown on the picture below almost all capacitors on the secondary side of the power board were bulged and in cases like this it may become fatal first on the inverter power line or on the main power line. Depending on that the TV may stop powering on or may stop losing back light (display) while still working.

In our case the Akai LCT3285TA had the typical problem of first not wanting to power on the first time the button was pressed and, after a few weeks, not wanting to power on at all.

Click on the pictures below for a higher resolution image and please pardon the quality  - they were made with a phone this time for a difference:

There were a total of 8 apparently bad capacitors on that board - two at the bottom, three in the middle, one at the top and two smaller ones hiding under the heat sink as indicated above.

I think I got a picture of those too, but when I got to posting the blog there was no picture in the phone and the TV was already closed and returned to the customer.

So here are the pictures were available:

Replacing the two below the heat sink required that first the two transistors using that heat sink get unscrewed from it and then the heat sink itself gets de-soldered from the board.

That's pretty much all of it...you can get the caps, find replacement and do it all by yourself...it doesn't get much easier than that...you can source the parts or you can just buy them at our store...or you can have us repair the board.

Either would be better than replacing the board with another used one that may do the same thing very soon!

Proview 3200 / RX-326 does not power on / shuts off / 200-100-HX276 problems

The Proview 3200 / Proview RX-326 is rather old and if you go through all the pain to actually disassemble it it may be worth to read this article to find if you can save a buck or two by repairing the power board and the main board by yourself rather than spending just south of $100 for a replacement of each.

These are the typical problems I am seeing with those TVs:

1) Completely dead TV - no front LED, nothing - suggests bad power board 02144-B306.
See this article for how to test it (note it's slightly different as its normal output is 12V and not 24V!) and if you need it repaired check the Coppell TV Repair online store.

2) TV comes on, but there's no display back-light. You may be able to see display changes with a flashlight or at the sun, but no back-light - that's either bad inverter or , very often, again bad power board.
See the links in the above case scenario for how to test the power board and send it for repair if you have to.

3) TV's standby light comes on, but when powered it either flashes green for a moment and then switches back to standby orange (or red) or switches to green, but display remains dark and you can't switch it back to standby color by pressing power, or display flashes for a second and then TV turns off, or sometimes it may turn on and stay on, but next time you try to turn it on it won't move...or any combination of the above.

This article is actually about that case...it's not only power board repair infomercial :-)

But, while at it, first and foremost again check the power board and make sure it produces reliable 12V on the primary as explained in our article.

If that's good then the problem is most likely on the main board 200-100-HX276 .

To make the long story short here's a picture of what you need to replace:

This picture was taken after the replacement was done.

The original capacitors were aluminum ones and did not show any signs of malfunctioning visible to the naked eye.

As you can see we've used standard replacements and not aluminum ones. In fact on this picture one of the larger ones is 680 uF. Don't ask - we just did it.

If you need the capacitors, drop us a note and we'll add a link for purchasing the four at a reasonable price. But the post here is with the main idea to share the know-how , not to benefit from selling the kit.


The replacement itself is not a rocket science, but is somewhat delicate partially due to the tight space.

Still way better than having to pay $90 plus shipping for a replacement board!