Toshiba 50H82 Convergence

15822 Views 18 Replies 5 Participants Last post by lcaillo, May 26, 2012

KrazyIvan

Discussion Starter · Jul 9, 2008

Okay, Thank you for all the info on this site. It has been very informative and I beleive I can pull off the repair myself. I have soldering experience with small LCD information displays for computers, wired to the parallel port. (I did all the wiring from a schematic drawing from scratch and did not burn anything

).

I have determined that it is highly likely I need new convergence IC's/resistors on my set. The red channel moves horizontally but not vertically and is offset by about 4 inches towards the top of the set.

I studied the service manual for my set and I understand that my set has stk392-110 IC's and that stk394-160's can be used in its place. I am looking at getting repair kit JT22052 (Hitachi X480293) to replace everything while I have the board out. I just want to verify that the resistors that come with the kit will work with my Toshiba set. The way I understand it, the resistors are paired to the IC and the current resistors will not work with the upgraded IC even if they are okay. Does that sound right or should I just get a stk392-110 kit?

Thank you for your time.

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lcaillo

· #2 · Jul 9, 2008

Forget the resistors in the kit. They are for Hitachi sets in a specific chassis series. You need to verify that the reisitors in your set are not damaged and if they are, replace them with the same values. The STK394-160 has substituted perfiectly in your set with no changes. The reason to by the chips in the kits from Hitachi is simply to be sure that you are getting OEM parts and to get the lower price.

I never use the STK392-110 any longer. Either the 392-150 or the 394-160 would be a better choice in every application that I have found. There have simply been too many problems with the 392-110, both from Sanyo and from counterfeit sources to ever bother with that chip.

KrazyIvan

Discussion Starter · #3 · Jul 9, 2008 (Edited)

Thank you for your quick response.

Now I need to figure out what the resistor values are. Is there a listing of resistor values with the 392-110 kit somewhere or is that model specific too? :dontknow: Better yet, does anyone know the resistor values or locations so I can identify them in the service manual? With the locations I can at least identify them on the board and read them directly.

raying:

Thank you once again for all your help.

EDIT* Oh, I forgot something. With the new IC, will I have to get into Service mode to reset the convergence or will the standard consumer access work to get things alligned again? If I do have to get into service mode, does anyone know how that is accomplished? The service manual I have does not make mention of how to get into service mode, at least from what I have read so far. I am going to have to check more carefully.

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lcaillo

· #4 · Jul 9, 2008

Ther resistors are specific to each model. Toshiba has no "kit" for your set. Other vendors might but I would not bother looking. Just ckeck the resistors while you have the chips out of the set. The service manual will list the parts for each location and the schematic will show the resistors on the output of each IC. Any convergence repair will require doing service level adjustment if you want it to be right.

KrazyIvan

Discussion Starter · #5 · Jul 9, 2008

Got it. Thanks again for all your help. A friend of mine is offering to help with the repair (he has TV repair experience) and he has instructions on how to get into the service mode.

I am ordering the kit today and will check the resistors with the board out of the set.

KrazyIvan

Discussion Starter · #6 · Jul 29, 2008

Well, I received the kit that included two STK394-160e's and various resistors. After ohming out the resisters we found one that was out of tolerance so it was replaced. I have put everything back together and it powered up fine. The convergence is worse now than it was before. It looks like looking into a concave lens. I can't even get in the consumer mode convergence, well, let me rephrase that. I can get in but it does not display the inital cross hair in the center of the screen and goes straight to the nine point convergence screen. I cannot view any of the cross hairs for any of the points and trying to adjust the convergence does nothing. I tried to do convergence in service mode and nothing changes. I can see the X and Y values changing but nothing else. When I try the "Touch Focus" (Hitachi equivelent to Magic Focus) It flashes "Touch Focus" on the screen then the screen goes blank, although I still hear sound. Powering down the set and turning it back on gets me back to a "viewable" screen but totally off in the convergence. Any suggestions?

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lcaillo

· #7 · Jul 30, 2008

Sounds like you don't have power to the ICs. You also need to resolder a number of connections that may be cracked on the board that the ICs are on.

KrazyIvan

Discussion Starter · #8 · Jul 30, 2008 (Edited)

lcaillo said:
Sounds like you don't have power to the ICs. You also need to resolder a number of connections that may be cracked on the board that the ICs are on.

I appreciate the information. I am going to pull the board out tonight and go over it with a fine toothed comb tomorrow.

And just a side note, I called a local repair shop just to get a feel for what they would say and they were rude and condescending. They told me that I probably burned the whole thing up and that I should have never used the STK394-160's as a replacement for the STK392-110's because they dont have enough power to handle the job. ??? Just thought I would share. I probably wont be dealing with them any time soon.

lcaillo

· #9 · Jul 30, 2008

Well, that shop is not one that you would want to deal with then, is it? The fact is that Toshiba has not recommended changing to the STK394-160, as it is a chip made specifically for Hitachi. Many techs have found that it is a superior replacement in the Toshiba sets as well as many others, just like in the Hitachis. The only sets that I have heard of problems with them in are the Philips sets, but then those are a bit flaky with any chips. They also use the STK392-120 which is a 4 amp IC as opposed to 3 amp. We don't know the current rating on the STK394-160, but Hitachi even uses them to replace the -120 chips. The bottom line is that this shop did not know what they were talking about. The STK392-110 was one of the most failure prone chips in the STK series that Sanyo ever made. Most manufacturers figured this out and shifted quickly to more reliable replacements like the STK392-150, -180, -120, and later the 394 series.

With the same settings I have verified the same output and 5-10 degree F cooler operation in the Toshiba sets when using the STK394-160 in place of the STK392-110. I have done dozens of them with never a single recall.

It is not uncommon for many shops to be more poorly informed than savy consumers like yourself. Many just do not do the research and homework, nor communicate with lots of other techs like some of us do. A lot of the reason that the service business has such a bad reputation and is dying off is the making of these very servicers who, in my opinion, are not very professional. Even if they were correct in their assessment of your situation, there is no need to be rude and condescending. You don't make long term success in business with that kind of behavior.

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G

· #10 · Sep 9, 2008

KrazyIvan

Did you ever manage to fix your convergence issue? I have a similar TV (Toshiba 61H71), and I think I am also having a convergence problem. Did you find how to get it into service mode? I am looking to buy the service manual, but I am unsure if it has the information that I would need to perform the adjustments after the ICs are replaced.

Thanks!

KrazyIvan

Discussion Starter · #11 · Sep 9, 2008

WannaTheater said:
KrazyIvan

Did you ever manage to fix your convergence issue? I have a similar TV (Toshiba 61H71), and I think I am also having a convergence problem. Did you find how to get it into service mode? I am looking to buy the service manual, but I am unsure if it has the information that I would need to perform the adjustments after the ICs are replaced.

Thanks!

I apologize for not updatig this thread. Unfortunately I was not able to fix my TV. After going over all the solder points and resoldering a few points, the TV worked for about 5 minutes. I powered it off and put everything back together. I moved the TV back into position and when I tried to power it back on it just gave me the red blinking LED of death. No sound or picture.

I am not sure what happened.

G

· #12 · Sep 9, 2008

Thanks for the update, even though the news is not good!

I am off to order parts today to see if I will fare a bit better.

ecollier2012

· #13 · Sep 2, 2009

If it powered down - after replacing the chips. You typically have one of the following problems.

1) Bridged connection - recheck all of your soldering again.

2) Bad IC Chip - Try removing one chip at a time - and power on. If video returns - you may have a bad chip or you damaged the chip during your repair.

3) Loose cable.

Good Luck,

www.TvRepairKits.com

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TravisS

· #14 · Jan 4, 2011

KrazyIvan said:
Well, I received the kit that included two STK394-160e's and various resistors. After ohming out the resisters we found one that was out of tolerance so it was replaced. I have put everything back together and it powered up fine. The convergence is worse now than it was before. It looks like looking into a concave lens. I can't even get in the consumer mode convergence, well, let me rephrase that. I can get in but it does not display the inital cross hair in the center of the screen and goes straight to the nine point convergence screen. I cannot view any of the cross hairs for any of the points and trying to adjust the convergence does nothing.

Ok this sounds like what is happening to me. I also have the TOSHIBA 50H82 and I also just put in the STK 394-160 chips in place of the 392-110. I can get into the consumer mode of convergence and also into the nine point and I can view the cross hairs but it wont adjust in any direction. Im starting to think the STK394-160 chips wont work in this model TV.

Hey KrazyIvan did you ever try to put different chips like the stk392-110 or stk392-140 or 392-150 into your tv before you gave up? You say it worked with the 394-160 for 5 min. Was your convergence adjustable and or good for that 5 min? Here is a link to my thread about my problem in case it will help anyone. http://www.hometheatershack.com/for...-tac-0263-now-convergence-not-adjustable.html

TravisS

· #15 · Jan 15, 2011

My TV works now read up here http://www.hometheatershack.com/foru...djustable.html

KrazyIvan

Discussion Starter · #16 · Mar 17, 2011

TravisS said:
Ok this sounds like what is happening to me. I also have the TOSHIBA 50H82 and I also just put in the STK 394-160 chips in place of the 392-110. I can get into the consumer mode of convergence and also into the nine point and I can view the cross hairs but it wont adjust in any direction. Im starting to think the STK394-160 chips wont work in this model TV.

Hey KrazyIvan did you ever try to put different chips like the stk392-110 or stk392-140 or 392-150 into your tv before you gave up? You say it worked with the 394-160 for 5 min. Was your convergence adjustable and or good for that 5 min? Here is a link to my thread about my problem in case it will help anyone. http://www.hometheatershack.com/for...-tac-0263-now-convergence-not-adjustable.html

Sorry for the late reply. Was just cleaning out my inbox and found this email in the clutter. I never messed with the TV again and gave it to a local repair shop. I ended up geting a 42" LCD Display. My dad just got a Phillips 65" rear projection that has convergence issues but I don't know if I want to risk it again.:doh:

TravisS

· #17 · Mar 17, 2011

Thanks for the update. I did finish fixing my TV read about it here. http://www.hometheatershack.com/for...-tac-0263-now-convergence-not-adjustable.html

bowler45

· #18 · May 25, 2012

I have an older projetion tv manufactured in 1999. Model #TZ50V61 chassis #TAC9950. The chassis had two stk392-110. I replaced them with stk392-120. The tv looked the same as before so I put two new stk392-110 as that's what was in there originaly. Needless to say the picture was the same as before. I can't move the red or blue when I put it on customer convergence. If anyone has any idea on what could be the isue please chim in. :crying:

lcaillo

· #19 · May 26, 2012

Please read the first ten posts of the convergence repair sticky in the DIY Repair forum VERY carefully.
http://www.hometheatershack.com/for.../5600-crt-based-rptv-convergence-repairs.html

I suggest starting a new thread with the model number in the subject.

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