Friday, January 7, 2011

Samsung 214T LS21BRBAB does not power / blinks once

This is a story about pragmatism. A tiny bit of knowledge sneaks it at some point, but for the most part it's just a story. If you expect ground breaking discoveries, mysterious occurrences or erotic adventures then you should move to some of the next posts. You may have better chances there. Bear in mind I am not promising anything.

A local customer called on the phone and asked if we can fix 21'' LCD monitor.

We told him it's probably cheaper to buy a new one these days, but he said he's curious what could it be and is ready to pay our minimal service fee for 32'' LCD TVs for us to take a look.

Monitor was 21'' Samsung 214T [R] S, model code LS21BRBAB/XAA and as customer told us he had looked it up on Google and, upon finding a common failure in the power board caused by bad capacitors, has replaced them to no success. So he wanted us to take a look and even if we can't fix it he'd pay us $55.

For your viewing pleasure, this is how Samsung 214T looks inside:

For the technically challenged and the rest from the normal side of the humanity the brighter thing on the left is a power board and the green thing on the right is the main board.

The power board incorporates in it functionality for providing the special needs of the florescent lamps that provide backlight for the LCD assembly.

Well long story short, the customer has replaced all caps on board and, from the look of it, has done it well.

The monitor was powering on all right, then the display would flash for a split second and instantly turn back again. Monitor would power on and off, just wouldn't stay bright.

Many LCD TVs have the same symptom and the cause us, overwhelmingly, in the circuits that provide power to the back light lamps. In large TVs they are often on a separate board, but smaller TVs and monitors they are sometimes incorporated in the main board just as shown here.

There are several reasons why something like that would happen and before troubleshooting it I took a quick peek at the power board. I was looking for a board label, something that would allow me to look it up on eBay and see what would it cost.
What I had come across was a label NB-20 towards the top of the board.

So I looked that up and a single result showed up offering me a "TESTED, WORKING POWER SUPPLY BOARD NB-20". It was asking $69.95 plus $9.95 shipping. Here's the actual link.(bear in mind it may be invalid by the time you read this).

$80 is a lot of money for a 21'' LCD TV. Way too much in my book.

But then again the link mentions that this is board "IP-58130A", so I searched for that.

Bingo! $26.99 direct from China, 20,000 sales seller, 98.8% feedback.

Reserved as I am , I think this is a no brainer.

I put together the TV as quick as possible and plan on telling the customer to pay me our standard fee less $27 and get a new board from there.

It's not about the money...and I know I can fix the damn board.

I just don't think I can do it the first time for under $27.


Bambooz said...

that NB20 model number is kinda irrelevant on samsung monitors.

the real model numer is the IPxxxxx one (stands for "*I*nverter & *P*ower board"

you can actually see it on this pic:

same thing goes for the LCD controller board on Samsungs, as can be seen here (Samsung Syncmaster 223BW 22" LCD monitor)

Model # is "BN41-00885B"

on the front in the upper right corner

and on the back

just by the way ;)

pie2mats said...

well, that's good thing to know... nice workable insights works well on future endeavor concerning the same issue..
plasma tv repair wentzville

Unknown said...

I love the trouble shooting and especially the kind that cuts prices in half or more! MOIST!

stevem said...

so did the replacement power-supply board fix the
problem ?

-steve m

KemalG said...

What solved the problem since it was not capacitors???

stevem said...

OK, I replaced the power supply and that fixed the
blank screen problem.
Bought it on ebay for ~$30. The screen has a little bit of flicker in parts of the screen. So, I think
I will replace the caps on this replacement power supply.

KemalG said...

OK, thank you Steve, I appreciate!
I'll try to do same!

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