# Problem. Substituted STK392-110 with STK394-160 in TOSHIBA 50H82 TAC 0263 now convergence not adjustable.



## TravisS

*(Update 2-5-2011 My TV is fixed and working great as of 1-14-2011 Read this thread to learn how I fixed it.)*

Read more: Problem. Substituted STK392-110 with STK394-160 in TOSHIBA 50H82 TAC 0263 now convergence not adjustable. - Home Theater Forum and Systems - HomeTheaterShack.com



I put my questions in bold so they are easy to find.
If this thread belongs in the (Home Theater Forum and Systems - HomeTheaterShack.com > Service | Support > Brand Specific Service Forums Toshiba) section please move it for me. I see no move thread option.


Read more: Toshiba at Home Theater Forum and Systems - HomeTheaterShack.com 

I substituted the original STK392-110 convergence chips with the STK394-160 chips in my TOSHIBA Model 50H82 Chassis TAC 0263 Manufactured DEC 2002. Now convergence is not adjustable. And picture is bowed kinda of uniformly on top bottom and sides (see photo). Maybe I lost power to the chips? *Has any one done this successfully in my situation (my model number) or do I simply have dead on arrival new chips?*

I got impatient trying to figure out how and who will ship to my location (many companies can’t seem to learn how to ship to Hawaii) and checked out eBay where I buy from often and am familiar with.
I was, and am still convinced the new chips I ordered are original. However the source of my chips is still questionable. I got them from ach te te pee rover.ebay.com/rover/0/e11030.m43.l1123/7?euid=f63833db3fab4c7383ca7f9bae54ed39&loc=http%3A%2F%2Fcgi.ebay.com%2Fws%2FeBayISAPI.dll%3FViewItem%26item%3D130462716164%26ssPageName%3DADME%3AB%3AEF%3AUS%3A1123
This seller ratings are good and that means a lot on eBay. DOA items will get a seller bad ratings. The price of $30 for the set is evidence they can afford to be real sanyo chips. His last statement kind of bothers me. *Is it true?* The eBay seller zulfikar2000 wrote to me in an email: 
Hello.
We use dozens of these monthly in our repair facility!
These ICs are genuine Sanyo chips. We have a certificate of authenticity.
And we are the only company that offers 90 day warranty on these.
STK392 series of convergence chips is sometimes forged but not this series (STK394).
Best regards,
Mersin Zeljkovic
Zemtronix

I have read the entire sticky about CRT based RPTV Convergence Repairs at http://www.hometheatershack.com/for.../5600-crt-based-rptv-convergence-repairs.html VERY NICE THREAD AND WELL PUT TOGETHER Thank You. And I read many other post from many web sites. 
I have been soldering for years on an assembly line altering and repairing circuit boards so my soldering job on installing the chips is A OK.
I tested all the resistors and they where good before the install.
I have the schematics for this TV some where.
Before removing the original chips I was able to move both the colors in the low level convergence manual adjustment consumer menu both directions. But not near far enough for one of the colors as it was bowed too far on the left. 
Now when using the touch focus button the colored lines dont move a bit (they used to) then it errors out (it started erring out even with the original chips after the convergence issue started.)
We used the set for only about 3 hours after the picture originally bowed one of the colors with the original chips.
I had to replace the common bad caps in the scan converter hyperboard last year. 

I inspected for cold (cracked) solder joints and found nothing but evidence of some past re soldering work done on the power boards larger capacitors. I also visually inspected everything for anything unusual. I did not check fuses. 


I know I did a fine job on the soldering but I cant rule out forgetting to plug something in. Ive gone over it 3 times and all looks good but I did not write down each step as I disassembled it because it was only last year that I had to take this board out to remove the hyperboard. It was easy then and I did not see the need to write it all down on paper. I did label the electrical wires and or plugs that had to be unplugged and or removed so they were reinstalled in the correct place.
I'm torn between buying or using the warranty to get another set of STK394-160 or just getting the STK392-150 because it is said to DEFIANTLY be a working upgrade in any TV set that originally used the STK392-110 that came stock in my TV. *What do you think about all this?*
Any experienced help greatly appreciated. Thanks, Travis


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## TravisS

Here is a response from the seller after reading this thread:
Hello.
We are, among others, Toshiba authorized service center and according to them STK394-160 convergence chips are not suitable for your model of the TV.
They will draw too much current for that power supply. We and Toshiba recommend using original convergence chips (STK392-110).
According to the pictures you posted it looks like that you may have a pincushion problem too. That problem can be related to the low power supply voltage(s) and/or due to a problem in the horizontal drive section of the high voltage circuit.
Please measure all the relevant voltages coming from the power supply. All those voltages have black square pico fuses in the circuit as well as safety resistors.

As a side note all of our convergence chips are from the biggest and most reputable TV parts supplier in the country, Encompass.

Hope this helps.

Best regards,
Mersin Zeljkovic
Zemtronix


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## lcaillo

The current rating on the STK394-160 is the same as the STK-110. The -110 is an inferior chip and should always be replaced with the STK-392-150 or in some sets the 394-160. In the case of Toshiba, there are reports of the -160 not working due to muting circuit differences. I have not seen this problem. 

Encompass has been known to supply inferior quality ICs, aside from those that they supply from manufacturers directly.


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## TravisS

lcaillo said:


> The current rating on the STK394-160 is the same as the STK-110. The -110 is an inferior chip and should always be replaced with the STK-392-150 or in some sets the 394-160. In the case of Toshiba, there are reports of the -160 not working due to muting circuit differences. I have not seen this problem.
> 
> Encompass has been known to supply inferior quality ICs, aside from those that they supply from manufacturers directly.


Encompass is on the sticky for good suppliers at this link http://www.hometheatershack.com/forums/diy-repair-maintenance/4396-repair-parts-distributors.html. But yet they may sell inferior ICs? That confuses me. 
You have used the STK394-160 in many TV's that came stock with the STK392-110 and you have never had this muting circuit difference problem. If a person where to have this muting circuit problem what are the symptoms? I know probably different symptoms in different situations but along what subject matter?


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## TravisS

lcaillo said:


> Be Thorough!
> Don't just assume that you have a convergence problem because colors don't line up. Verify that you cannot adjust it. If all of the adjustments for R,G,& B, both horizontal and vertical have an effect, your problem is somewhere other than the output ICs.


That quote is from the convergence repair sticky at http://www.hometheatershack.com/for.../5600-crt-based-rptv-convergence-repairs.html post 5. *If this is always true then I did not have a problem in my output ICs any way?* I was able to adjust both directions just not far enough not to mention the bowing. I figure as common as it is that the STK392-110 IC goes bad. With my TV set being 8 years old I may as well replace them any way. How long ago did they start using the STK392-110 chips? How long is the longest that the majority of the STK392-110 can last? Are the STK chips hot and in use even when the TV is off? Or just warm, I assume they get no dc offset when the TV is off. It sounds like they will last longer (cooler) if the dc offset correction required is lower. I feel like it will be every year I will have to tear this TV apart and fix something because its old. That wouldn't be worth it. But its fun. 
Something is off with my TV set thats for sure. STK related or not I will find it.
To many questions I think. Maybe I can answer them my self with some testing and looking at the schematics.


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## TravisS

*My TV is fixed and working great. 1-14-2011*
Hmm I really expected better info from the users here. I have tried to make this thread as informational as possible to help any others get through there problems if they are similar to mine. 
So today I went over my work and all looked good. And I removed the new STK394-160 that I put in last month. I then installed STK392-150 from the same seller on eBay. The TV works great for 1 week now. I don't expect any problems with the TV for a few years. Id like to confirm that the STK394-160 I had put in are actually good. If my TV didn't ruin them. Any takers? I will mail them to you free if you want to test them. You can keep them. Can they be bench tested? I have an ignition module tester for cars that puts the ignition module through its natural courses to see if it performs well. Something like that but for this chip is ideal instead of having to put all the work into installing them in a TV set. If you want them PM me your address and how you plan to test them. 
So far I am nearly convinced that the STK394-160 will not work in my model TV. There are other people that have tried it in this model with similar not correct symptoms.


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## SLR_65

Hi Travis,

I wanted to thank you for the nice thread! :T

I understand your disappointment at the lack of user input on this forum. It seems that there are more consumers just looking to fix their tvs here than there are service techs. Pretty much Leonard is the resident tech and just occasionally another will check in. Sooo, unless someone has your exact set there isn't much help available - Leonard doesn't have time to grab the service manual and do the research for ya nor does he know your skill level - it's just really hard to give anything beyond general help via crystal ball!

It isn't just this forum, this is common in most of them. There are a couple with a few more techie types but they aren't well moderated and the people selling kits get really old . . . you know how it goes, you need some help and the only answer you get is "the best advice I can give is to go to . . . yadda, yadda, yadda. In actuality that may not be bad advice as at least one of the kit vendors does offer some help if you have problems but if you're like me you're cheap so you'd rather pay half as much for the parts, find a free manual online and hope you can find some free help on the forums! 

This is why when I work on one of these I try to document everything - hopefully it'll help someone else. And this is why I really appreciated your post! 

I have wondered about that vendor on eBay also, as well as sewsales. Both offer warranties and both have excellent user feedback. At their prices though there stuff almost has to be Chinese knock offs so my first inclination would be to avoid them but my usual STK supplier, ACME Sales of Orlando FL, is now carrying a Chinese STK392-570 they claim they have tested and found to be as good as the originals. This tells me that some factory in China is capable of producing decent quality STK chips, so I really wonder if these two vendors haven't also found that factory?

On the other hand . . . most eBayers post feedback shortly after receiving their product and from what I gather most of the lower quality chips will usually work for a little while before quitting. since eBay doesn't allow you to revise feedback I wonder how accurate the feedback rating really is?

Most of the sets I've fixed have been for family and friends so I haven't wanted to chance bad chips so so far I've only boughten from reliable sources.

My son and I just picked up a freebie Philips though and it's probably going to stay with my son as a gaming machine (not something someone would be counting on to watch every day) so I really thought about testing the waters and trying some cheap chips from sewsales but my son said he wanted to be the lead worker on this set and just wants me to hold the flashlight and take pics. He's not overly experienced with electronics and soldering so I didn't chance it - for the $20 difference in price I just thought it was better to eliminate that variable if we have trouble getting it going.

His statement that the 394 series of chips are not counterfeited I don't think holds much water - I think they'll counterfeit anything they think there's a demand for and they can make a buck on.

I've boughten a couple sets of STK394-160s from Encompass without issues, though I bought them in the Hitachi kits, not seperately.

The STK394-160 was only produced for use in Hitachi sets so their use in any other set can be a gamble, I agree - it would be nice to have a listing somewhere as to what sets they've been used successfully in.

I'd also be interested in knowing how the differences in muting manifest themselves in incompatible sets.

As far as the age of your original chips - I think eight years is a pretty successful run on a set of 110 chips. I think a lot of it has to do with the quality of the original work in assembly - several of the sets I've worked on have only had a smearing of grease that covered about half the chip! On one of the sets the screws that held the chips to the heat sinks were finger tight! When I replace them I make sure the whole chip is covered, I use Arctic Silver grease, and I make sure they are snugly screwed down.

I would like to test your STK394-160 chips as I'm really curious as to whether they were the culprit or not too, but alas I don't have a project to try them in right now. I'll drop you a note if I do though and see if you still have them.

Again, thanks for the *great* thread! If you don't mind . . . if the set is still running fine in six months or so give us an update and let us know.

Take care,

Steve


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## SLR_65

Hi Travis,

I think I have another reason why some chips go out sooner than others - poor quality heat sinks. I was working on a Philips tonight. I usually use a utility knife blade to scrape the old heat sink grease off of the heat sink. Usually it gets most of it but tonight I could see what the grease was filling in an obviously wavy surface on the face of the heat sink - it's a cheap stamped thing.

Oh well, it lasted five years on the original chips. I'll use Arctic Silver grease and maybe we'll get a couple more out of it.

Take Care,

Steve


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## lcaillo

TravisS said:


> *My TV is fixed and working great. 1-14-2011*
> Hmm I really expected better info from the users here. I have tried to make this thread as informational as possible to help any others get through there problems if they are similar to mine.
> So today I went over my work and all looked good. And I removed the new STK394-160 that I put in last month. I then installed STK392-150 from the same seller on eBay. The TV works great for 1 week now. I don't expect any problems with the TV for a few years. Id like to confirm that the STK394-160 I had put in are actually good. If my TV didn't ruin them. Any takers? I will mail them to you free if you want to test them. You can keep them. Can they be bench tested? I have an ignition module tester for cars that puts the ignition module through its natural courses to see if it performs well. Something like that but for this chip is ideal instead of having to put all the work into installing them in a TV set. If you want them PM me your address and how you plan to test them.
> So far I am nearly convinced that the STK394-160 will not work in my model TV. There are other people that have tried it in this model with similar not correct symptoms.


Forums are about sharing information and collaborating. No one should expect others to have the solution to every problem nor that because you don't get what you expect, people are not willing to share and help. It is far more likely that there is not a good answer and that the only way to get to the bottom of your problems is to have the set there to test and experiment.

I have said many times that I have heard of problems with the 394-160 in some sets due to differences in the muting operation in some models. I have not been able to confirm this, and have used them in some Toshibas and they worked fine. There are simply too many variables to be sure without testing directly. That is why I don't recommend using that sub unless you have specific experience with your model that indicates it is a good choice. The 392-150 is a universally safe sub for the 392-110.

I have seen many intermittent problems with this chassis that can be affected by simply moving the boards around. Be sure to check your work and connections throughout the chassis.


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## SLR_65

Hi Leonard,

I agree to an extent, but in this case there are lots of different tv brands and models so it's hard to collaborate as only a few of the forum members probably have the exact set you are working on. Beyond that, most of our members here aren't service techs by any stretch of the imagination - they are just end user consumers trying to avoid an expensive repair bill. As such they don't have the knowledge, skills, or equipment to troubleshoot anything but the most routine problems so I suspect in most cases those sets are simply thrown away without the owner even attempting further repairs so those forum members truly have nothing to add to the knowledge base.

Ham radio and other electronics related forums are full of experimenters and hobbyists so help and collaboration is abundant on them but with these tvs it seems there are mostly end users looking for a quick/inexpensive fix and that's it. There are a few techs such as yourself who try to lend a hand but your time is limited and troubleshooting via long distance is a hard thing to do - especially when the person on the other end trying to do it isn't skilled at all in electronics. There's just a couple like Travis and I who are in between and we're doing our best to help build the knowledge base, but it's a big subject.

It's a sad fact, but a fact none the less - The majority of the forum members wont have anything to add, it's not their fault - they just aren't skilled in the field. A very small number of the members are service techs or elsewise skilled but their time is limited and it's extremely difficult to help a novice from a long distance, especially when the subject can get quite complex in a hurry. An even smaller amount it seems are like Travis and I - pretty much end users also, but we're persistant ones who do know a small amount about electronics, have the basic skills (how to use a meter, soldering, etc.), and can follow directions so we keep hammering away on problems and sometimes we actually get them fixed (usually with the help of you techs on the forum) and we try kick in as much as we can.

I am surprised that the amount of hobbyists is so low though - I've actually found working on these things to be a bit addictive and an interesting hobby, but I guess I'm in a minority! LOL!


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## SLR_65

As far as the STK394-160 chips go . . . yeah, I think the only "slam dunk" is the Hitachi sets they are designed for. You can try them in other sets but don't be surprised if they don't work. Every time I use them I'm aware of that fact and I'm fully prepared to pull the thing back apart and buy and install new chips. If you're just wanting to get your set up and running as quickly and cheaply as possible then experimenting with the 
160s (and that's exactly what it is - an experiment) probably isn't a good idea for you.


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## TravisS

Thank you Lcaillo for having the best and most informative posts on this websight. After all it was you and this websight that taught me how to fix my tv. It is still working great as of 3-6-2011. And I am still offering the set of STK 394 160.


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## lcaillo

I appreciate the offer but I have some and am also not actively in the repair business any more. If my current position does not turn out to be permanent, I may be activating my business again in a few months, but for now don't really need them. Someone else may want to experiment.


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## hr2

Hey Travis, if youve still got those 160s to give, ill take em! Im new to the forum, and Ive got a Hitachi that just might be able to use those 160s. The tv originally came with the stk 150s and im not at all shy about givin those new ones a try. I cant PM yet, and I cant post a complete email address, so get back to me at hromero yahoo com. Thanks!:T


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## hr2

Sorry, lets try that again. Email me at hromero cyberdude com. Thanks! :bigsmile:


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## TravisS

hr2 said:


> Sorry, lets try that again. Email me at hromero cyberdude com. Thanks! :bigsmile:


According to the sticky at http://www.hometheatershack.com/for.../5600-crt-based-rptv-convergence-repairs.html Hitachi replaces your STK392-150 with these STK394-160. I got your mailing address today there will be no tracking number. First class mail. I will try to drop it in the mail Friday. Do you need heat sink compound? If yes I will put some in a plastic bag in the package for you.


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## TravisS

I drooped it off at the post office today. No heat sink paste included. Keep us posted.


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## hr2

Youre the man! Thanks. Ill let you know how it goes. :T


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## hr2

Well, Travis helped me out by sending me those ics. Unfortunately, they were probably bad when they got here because I blew a coupla resistors and now the convergence is worse than before. Oh well, cant say i wasnt expecting it. Ive already ordered up a fresh batch of chips. Thanks anyway, pal.


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## TravisS

Oh well. Let us know how the new chips work out.


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## E_ROCK

My 50H82 had the same problem. I just replaced/upgraded the STK392-110 chips with STK392-150 chips and everything is working perfectly. I also ordered but did not install the resistor pack.

Thanks,


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