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Im about to replace the Convergence IC on my Mitsubishi ws-55511 is it better to completely remove the board or is it possible to replace the IC while installed in the projection unit.
 

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It depends on the set and how the wires are dressed. IIRC, I usually just pull the chassis out and stand it up on these, removing a few wires to get the slack needed.
 
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Hello,
I have a Samsung HCM5525W, I replaced both Ic's, and when I fired it up I cannot adjust red, and it is bowed along the top and sides. I check and found that I had two burnt resistors, the rz144 and rz145. I replaced those with 2 3.9 ohm 2 watt resistor. When I turned the set back on the red is still not adjustable. When I was removing the IC's i did knick the board a bit, but I bridged the gap I created with a bit of solder. Any advice on what could be causing this problem? Thanks in advance for your help!!

-Warren
 

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Open connection, damaged IC, inferior parts quality, bridged solder connection, DCU problem... lots of possibilities, check your work.

Please start a new thread when discussing a new problem.
 
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This may have been asked elsewhere, and I read everything from the first page the third post. I have a Pioneer SD-643HD5 with convergence issues. I am going to replace the ICs on the convergence board. I pulled the board out and found they are the STK392-110's, but I have two STK392-180's. I got them after reading this post:

http://home.earthlink.net/~oleg.filippov/ConvergenceFix.htm

Are these the wrong IC's for this board? Should I reorder and get the 394-160's or will the 392-180's work well enough? Thanks for any help you can provide on this matter.
-Robert

EDIT: Is this the wrong area for this question? Do I need to start a new post for this question? Apologies if I have posted incorrectly.
 

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The STK392-180 is perfectly OK as a sub for the STK392-110 IF the manufacturer was actually Sanyo. The important question here is where did you get them and how sure are you that they are not a counterfeit or second quality part?

Yes, you should always start a new thread for a new question. This is the right forum in which to post the question.
 
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Hello,
I have a Samsung HCM5525W, I replaced both Ic's, and when I fired it up I cannot adjust red, and it is bowed along the top and sides. I check and found that I had two burnt resistors, the rz144 and rz145. I replaced those with 2 3.9 ohm 2 watt resistor. When I turned the set back on the red is still not adjustable. When I was removing the IC's i did knick the board a bit, but I bridged the gap I created with a bit of solder. Any advice on what could be causing this problem? Thanks in advance for your help!!

-Warren
Hello Warren. I just fixed the convergence on an HCM5525W a few months ago. You need to find the two fuses near the convergence chips. They are solid green in color, and look exactly like resistors, but without the color bands on them. They're both soldered on the board, so you'll have to remove the board from the set. One, or both have failed. These are identified on the under-side of the board as a sine-wave. You can use your ohm meter directly across, and see if you have continuity or not. Their values are printed on them in really fine print. I forget the value myself. They cost a little over a buck each.

Also, I had to replace 6 resistors. If there is any discoloration on the PCB underneath the resistors, you should replace them. Its good practice.

Let me know if you need any more guidance. Good luck!
 

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I have a Mits 46809 and I was seeing the red ghosting to the right. I read and reread this site and decided to open up the TV and take a look-see. After unplugging the TV and verifying that it wouldn't power on, I took the back off the set and surveyed the layout. I then removed the speaker cover from the front of the set (pulling on the bottom of the cover, gently pop the corners loose and then middle to release the cover) and found the access panel. I opened it and surveyed some more. The number of tiny wires was very intimidating. But after rereading the entire thread, I decided to give the repair a shot.

Starting from the back of the set I was able to immediately find the largest heatsink located in the middle of the TV. I removed the 3 screws along the back side of the black frame. I wasn't able to get the assembly to move until I went around front and found the two black tabs on the front of the frame. Once the tabs were released the entire assembly was able to slide out the back. Wires prevented me from getting it far enough out to look underneath. I was able to tip it up and look but there was no way I was going to be able to solder upside down. I then decided to unplug each of the wires on the left side of the assembly. This allowed me to slide the frame out and flip it over. I was able to position the TV so that I could rest the right side of the assembly (the side with wires still connected) on the back of the TV and the left side of the assembly on my fireplace hearth. This gave me a perfectly level place to solder.

Early Saturday morning I went to Radio Shack to buy the necessary tools and solder. I bought the 25W pencil soldering iron, the recommended desoldering iron with the red bulb, the thinnest 62/36 solder, desolder braid (just in case I made a mess) and the helping hands w/magnifier. The total bill was $48.50.

To start the repair I used the magnifier to look closely at the existing solder points and determined that an end pin was discolored. I decided to start with that one. Two others looked like they were starting to form rings but they looked ok. I plugged in the desoldering iron and after it heated cleaned the solder from the pin. This tool made it a breeze. Now time to solder. After the iron warmed up I touched the solder to the tip to "tin" it. I then touched the iron to the pin and board, waited a couple of seconds, and touched the solder to the base of the pin. There was a bunch of smoke. I got scared and pulled the solder away too quickly. I only covered half of the pin. So, I warmed the pin and solder again, added more solder and got the rest of the pin. I briefly contemplated doing the rest of the pins while I had the TV apart but decided not to attempt it. I'll probably regret not doing this later.

I wanted to test to see if the problem was fixed so I put the board back into the TV, reconnected all the wires, put all wires back into their tie downs, and plugged it in. I waited for smoke and didn't find any. I then reluctantly powered on the TV and again, no smoke. The ultimate test, I went to the convergence menu and found a perfect white plus sign. UNBELIEVABLE, IT WORKS!!! Just for good measure, I decided to reset the convergence to factory settings. I then reconnected all the TV inputs and watched my Tivo'ed World Poker Tour episode. The picture was perfect.

If I can do this repair anyone can. I am a bit of a do-it-yourselfer but by no means a professional handyman. I have replaced a motherboard in a computer but I have never soldered before. The instructions here on this site were enough to get me through the entire repair. If you take your time, you can do it too. If you need tools I have a soldering iron and desoldering iron that were only plugged in once. I also have a spool of solder that is only missing about a quarter inch. I'll sell all three for $20 plus shipping.

Thank you lcaillo! I can't thank you enough for this thread. You saved me $400!!! (that I promptly deposited in Atlantic City)

Sincerely,
Mike
 

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Next time, give a little to a more deserving charity. :bigsmile:
 

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Hi All,

A while back I posted to this thread asking for help fixing my projection TV. A pioneer that I don't have the number in front of me right now.

A BIG THANKS to all!

My 13 year old son and I replaced the IC chips with Sanyo parts and the puppy looks great!

The original problem was the base green grid was wavy on the left. The local shop thought that the IC fix wouldn't do it. After much time with you all, the set is now back.

MANY THANKS,

Richard
 

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I have a question on my Pioneer elite pro 118 RPTV

From looking at the forums and other info I believe that my convergence chip is most likey bad
the question i have is i can onlt find one stk chip in the front panel of the tv the chip number is stk4274 is that the convergence chip for this tv and is it the only one.

Here is a link to what the picture looks like http://sheltonfamilyonline.net/tv.jpg
Thanks
Alan
 

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Discussion Starter #152
This set uses the STK4277L for convergence, which is a 5 channel IC. It uses a single STK4274 which, IIRC, drives the vertical deflection. The convergence IC is under the heat sink.

Be careful to buy the part from one of the distributors in the parts distributor thread, and look for bad solder joints and damaged resistors.
 

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Thanks I found the other IC its a big one. All the solder joints look good around the chip but i did find a capacitor I think that had a bad solder joint and i fixed it so hopefully its just a bad chip and not a whole board. Also should I replace both ICs or just the STK4277L one. Do you know if I could buy a whole convergence board or would it cost to much thanks again for the help.
Also Is there a place i can get a service manual online for this tv

Alan
 

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I have a Panasonic PT-65WX50 65" Widescreen RPTV 01-05-2001
The symptoms look and sound the same for requiring replacement of the convergence chips.

The slight difference is that I had the TV recalibrated 5 months ago. The TV was starting to look darker and it had lost some of it focus and clarity over 7 years. I happen to own the service manual.

The first technician sharpened up the picture and convergence, but messed up the pincushion in the process, and refused to come back and fix it.

The second technician managed to make everything perfect. This was not a simple convergence. In both cases various resolution grids were on screen and each point adjusted for RGB.
I also printed alignment grids for the task.

So now I am wondering if I was seeing early signs of chip failure 5 months ago.
I am also wondering if the adjustments we made back then are going to create a need for another lengthy recalibration to adjust for the new chips.
It's that concern that has me calling for the professional, rather than firing up the iron.
 

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Generally, when replacing output ICs, you end up needing to do minor convergence adjustment. Major geometry would be rare. If, however, the set was ajdusted with a failing component, it may be that more correction is needed once the parts are replaced. There is no way to tell other than to repair the set and observe.
 
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What a wonderful thread!

I have a Magnavox 51MP392H/17, and the red convergence has died. I checked inside, there are a couple of resistors that are discolored, (along with associated discoloration on the PCB. I was unable to find out if the STK394-160 IC's are drop in replacements for my model, so I ordered the 394-120's, and a bag of resistors, (from one of the recommended suppliers). Now to find a service manual....
 

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I installed the new IC on Friday I didnt have any of the thermal grease to put between the chip and heatsink i will get that today but i did hook it all back up and turned the tv on for a few minutes just to test it and it did fix the problem but it was not on for long. after i get the grease for the heatsink i will test it more by watching tv again :)
 
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What a wonderful thread!

I have a Magnavox 51MP392H/17, and the red convergence has died. I checked inside, there are a couple of resistors that are discolored, (along with associated discoloration on the PCB. I was unable to find out if the STK394-160 IC's are drop in replacements for my model, so I ordered the 394-120's, and a bag of resistors, (from one of the recommended suppliers). Now to find a service manual....
I found the service manual online, (very inexpensive). While taking things apart, and removing the dead ic's I discovered that one of them had a single 'glob' of heat sink compound...that covered approx 20% of the metal back....and that was the only contact the ic had with the heatsink. It was very thick....and dried out. Replaced both IC's, (I used arctic silver thermal compound), and four 6.8 ohm resistors. Fired it up, worked great, and convergence was dead on.

Question for anyone with a similar set: How long do the crt's last? I read somewhere that 10,000 hours was about all you could expect, and another site simply said years and years. I'm trying to decide if it might be worth looking for some spares, while I don't need them...in anticipation of when I will.
 
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I am new to this Forum and am also a novice in the TV/Electronics area.

I have a Sony KP-65WV700 Rear Projection 65" TV that started to show Convergence problems.
I had a technician take a look at the set and he basically said that it is going to cost at least $550 to replace the IC chips.
He also said that the problem looks like it is probably more than the IC chips, but he cannot confirm until he fixes them first.
He suspects the DCU (Digital Convergent Unit) may also have gone bad because he sees a lot of distortion on the top and bottom of the screen.
That would cost me another $500, if it happens to be the case.
All in all, it is going to be at least $550 and at worst $1100.

There is no reason to suspect him because he also said that it is in my best interest to start looking for a new TV instead of spending on repairs.

Having said all that, I thought that I should probably try to repair it myself (after reading this forum) before I throw the TV out.
I have got nothing to lose - correct?

I understand most of the things said here in this forum, but would like to know where to start exactly.
Where would I find what IC chips I need exactly and if I need any other resistors or fuses and what kind?
What other tools do I need in order to do this?

Can somone please be kind enough to guide me through?
 
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