Big Screen Died ~ Need electronical help

It wouldn’t power up any more a light just kept blinking. It is a 3.5 year old Mitshibushi 61" DLP. I Googled the model number and blinking light and had hundreds of hits. There are 4 capacitors on DM board that go bad. If you have it serviced it runs between $700-$1000 for labor and they replace the whole DM board. But because the internet is such a great place there are forums where you can download the service manual and even how to's with pics on replacing the 4 capacitors. I have a friend who is a PC tech and has the desoldering tool and he offered to do it if I got the capacitors.
That part went off with out a hitch, the parts were $.056 each
but when he was putting the board back in he must have bumped the corner of the board while seating it into place. Broke some little choke coil (I think that’s what it is called) it is about 1/4" square and has 3 leads. Of course Mitshibushi will not sell the parts or give you the time of day and i really dont know what I am looking for.

Here is a pic of it, its the small square thing on the very corner, its at the weird angle.
http://archeryproshop.com/DM.jpg

If any of you electronical geniuses out there could identify this or at least give me some direction it would be greatly appreciated
.

It looks like it just got desolded a bit. I'm going to guess it's a transistor of some type. Is it really broken? If there's still a metal contact that was soldered down, resolder and you're in business. Are you sure you just didn't have the bulb go out on you?

Yea its broken. I am almost certain it would have worked after we replaced the capacitors if we had not hit that one.

Its an Inductor (or coil), all inductors have reference designators starting with "L", that one looks like "L9821", Bobby is right if there is enough of the lead left on the component then you can bridge the solder up to it and make the repair. Just be carefull when bending the component back down to the board that you don't break the other leads. Just dont use any flux when soldering it, the bridge with be easier to make kthat way.

If there is a number on the outside of it try googling that or go to radio shack and show them the number off of it, they may have one there.

On second glance that looks like a leadless component and you will have to see if there is a little metal pad still attached to it.

best bet is to unsolder the whole thing and remove it from the board, and inspect it. If you have a heat gun (capable of 600 deg or more) that would be the best way to get it off with out damaging the component any more.

I deal with these every day and those pads on there come of very easily. so don't pry it off or anything like that. you need to melt all the solder on all three joints at the same time to get it off.

basic "How To"

http://www.sparkfun.com/commerce/present.php?p=SMD-HowTo-6

We have the old one off, its toast. there are no markings or numbers on it at all.

That sucks dude, not much to do in that case. do you have any TV repair shops around you? If you can find one they may be able to hook you up with the part or just put a new one on there for you. I would try to talk to them and get a part number for it. I am sure that it cost less then a buck, those things are usually cheap. See if they will look up the number for a couple of homebrews.

I tried googling L9B21 but nothing. It could be a custom part if it's not etched or stamped on the device itself.

Ya know, the 1080p LCDs are really coming down in price and so are the front projectors.

would the inductance really matter that much? usually they are only in to chop off some high frequencies and if you replace it with one that is somewhat close it should still work. If the board is toast otherwise you may want to give it a shot. Unfortunately I don't even know what part you would replace it with.

The L9B21 might just be a running number for this particular device on the board.

BTW, how many pins are there? 2 or 4. It it's 4, it might be a transformer and replacing it will be more difficult.

Not an expert here, but I had a few classes on this back in school and used to do this tinkering as a hobby.


Kai

Bobby_M said:

I tried googling L9B21 but nothing. It could be a custom part if it's not etched or stamped on the device itself.

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Do you think it could be one of these Voltage Limiting Diodes? I think the number printed on the board is L9B22 for both of them.

Bobby_M said:

Ya know, the 1080p LCDs are really coming down in price and so are the front projectors.

Click to expand...

Actually I ordered a Toshiba 65HM167, it will be here next Wednesday, but I would like the old one fixed for in the bar

[YOUTUBE]JYb-htNQM6w[/YOUTUBE]

Kaiser said:

would the inductance really matter that much? usually they are only in to chop off some high frequencies and if you replace it with one that is somewhat close it should still work. If the board is toast otherwise you may want to give it a shot. Unfortunately I don't even know what part you would replace it with.

The L9B21 might just be a running number for this particular device on the board.

BTW, how many pins are there? 2 or 4. It it's 4, it might be a transformer and replacing it will be more difficult.

Not an expert here, but I had a few classes on this back in school and used to do this tinkering as a hobby.


Kai

Click to expand...

It's a 3 pin, I think the number printed on the board in front of both of them is L9B22 but I will have to look at it Monday, its at a friends house right now and the picture isnt real clear. I had been thinking the B was an 8 before Bobby posted with the B in his number.

The L9821 number on the board is just the referance designator, not the part number. As in "Inductor number nine thousand eight hundered and twenty one" not that there are that many on the board but that is how they designate them for the schematic so when they look at the drawing they know which one it is on the board.

I do component level repair on circuit boards and it is an Inductor, Kaiser you are right though there would be a range of ones to use but i wouldn't stray too far outside that range. If it is used in conjuntion with some capacitors and resistors to limit the curent or supply voltages to the card then you could fry a couple of components. And not knowing the value of the exsisting one then you don't know what your limits are.

what is the make & modle of the TV may be you could find a schematic on the interwebs, or call a TV repair shop and ask them where you could find one. I bet they have one.

Eh it may be a "B" but it is still the reference designator just to let them know where that inductor goes.

I am no help on the aprt number but, if it were me, I'd be happy to get out from under a Mitsubishi TV. I have one, and have sold them. They are'ny very reliable sets (judging by the full Mitsubishi repair shops).

When mine was under warranty, it was being repaired frequently. Now that the warranty is gone. It just won't die and the picture is slowly, but noticeably degrading. Most of the time, it's just hard to look at even in 1080i.

Yes, its a location designator. I see L9B21, L9B22 and L9B24 on the left hand side.

What sucks is, that it's not easy to measure an inductor w/o special eqipment. Unlike a resistor where you just need a good multimeter.

I guess it's a gamble. Try to replace it with something similar and risk breaking more or paying much more money to have it fixed professionally.

Kai

I have the schematic from Mitsubishi but it just gives a part number for the board. All the places I called said that the whole board will have to be replaced.
It has been a nice unit so far, and if I could fix it for cheap it will make a nice bar room TV to watch the Packer games on.
We pulled two recliners from the living room into my little office and have been watching my 32" Magnavox.
It's kind of a bummer we could have had it fixed for a few bucks but messed it up putting it back together.

If you're at your last resort.... I have the equipment at work to measure the value of an unknow inductor. If you want you can send it to me and Ill see what I can do with it. It does have the pads left on it or at least pieces of them right?

Virtuous said:

If you're at your last resort.... I have the equipment at work to measure the value of an unknow inductor. If you want you can send it to me and Ill see what I can do with it. It does have the pads left on it or at least pieces of them right?

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I might take you up on that. Thanks

can you scan or post up the schematic. I can see what i can figure out from there. What you really need to do is find a place that does warranty or contract work for tv companies, Like This Place, and call them to try and find the part number, i bet that they would be willing to help you out. what is the P/N for the circuit board and the model of the tv and I will call a friend who works for PTS electronics and see if she can't get me the number for you.

WOP31 said:

can you scan or post up the schematic. I can see what i can figure out from there. What you really need to do is find a place that does warranty or contract work for tv companies, Like This Place, and call them to try and find the part number, i bet that they would be willing to help you out. what is the P/N for the circuit board and the model of the tv and I will call a friend who works for PTS electronics and see if she can't get me the number for you.

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I have it at work, I will get it Monday.
I did call that place last week. They do not stock the complete board & can not get it.
I was then told they do not sell just parts. Only complete boards and assemblys.

I got a friend (a couple of them actually) that work in the TV repair dept at the one here in Bloomington, like 2 miles from my house. If you get me the model number of the TV and the circuit card PN, i can probably have one for you in a couple of days and fed-ex it to you.

WOP31 said:

I got a friend (a couple of them actually) that work in the TV repair dept at the one here in Bloomington, like 2 miles from my house. If you get me the model number of the TV and the circuit card PN, i can probably have one for you in a couple of days and fed-ex it to you.

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Sorry somehow I missed this post the first time around.

It's a MITSUBISHI WS-65813
The part number for the whole board is 934C067002 ASSY-PWB-DM

this is the part I broke when sliding the DM board back in:
(it's less than 1/4" sq.)

Virtuous said:

If you're at your last resort.... I have the equipment at work to measure the value of an unknow inductor. If you want you can send it to me and Ill see what I can do with it. It does have the pads left on it or at least pieces of them right?

Click to expand...

The schematic I have just shows the whole DM card or board, no help on the bazillion small parts on the board.

Did you ever resolve the issue with your Mitsubishi TV's DM board, i.e., the inductor? If so, what did you end up doing?

samsterdog said:

Did you ever resolve the issue with your Mitsubishi TV's DM board, i.e., the inductor? If so, what did you end up doing?

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I've got the part now. Figured out it is a small transformer wound 2:1. Trying to get some one to identify the package type and try to find a replacement. Will have a 50 50 shot of getting the orientation right though. Contacted several of my repair gurus and no one can find a schematic for that specific board.
I am thinking that this TV might have had been changed in the middle of production without changing the model #. Superior, you sure this is a DLP tv? Cause all the drivers on the video side in the schematics is for a CRT projection TV. If it is a DLP Ill try to find a manual for a similar model.

You are correct, it's a CRT

Was hoping you would say DLP... Really starting to sound like Mitsubishi doesnt want that board repaired period. I'de love to get ahold of the original guy who figured out the cap fix and find out where he got the schematic

I just got this today 4 weeks after I emailed them. I will call them tomorrow, I am thinking I will just get the runaround but its worth a try.


From: MDEA Service [mailto:[email protected]]
Sent: Wednesday, March 05, 2008 1:41 PM
To: Rich
Subject: RE: MITSUBISHI WS-65813

Thank you for contacting Mitsubishi Digital Electronics America, Inc. We are pleased to be able to assist our customers via our website.

Unfortunately, we are unable to assist you with your inquiry via the internet. Please contact our consumer relations department at 800-332-2119 for assistance.


From: Rich
Sent: Wednesday, February 06, 2008 3:18 PM
To: MDEA Service; [email protected]
Subject: MITSUBISHI WS-65813

To whom it may concern,

I have a MITSUBISHI WS-65813 that I purchased new on September 14, 2004 at a cost of over $4000
Like many others it is now in need of a new DM module to correct the blinking green light. My closest MITSUBISHI service tech is in Duluth, MN (75 miles away) they said if I bring it in they could replace it for $700 if they come out it could be over $1000.
I have no way of getting a TV of that size there in the middle of a Wisconsin winter so that is out of the question.
What will you do to get my TV working again?

Sincerely,

Rich

When you call them see if you can get part # L9B21. That is for sure the part number. I'd like to know why that the DM is the only board with parts and schematic omitted from the Service manual. I never believed that things were designed with product end of life in them but I am starting to change my mind.
Even if you went by the manual you cant find a replacement easily because they reference Mitsubishi's part number. Frustrating.

I just broke L9B21 on the DM module board so I am very interested in what the outcome was