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Discussion Starter #1
Hello!

I have a Toshiba 61H71 that is about 7-8 years old. A few weeks ago I started getting what I think are “Convergence Issues,” specifically with RED. The issue is predominant in the lower left corner (looks like half a sine wave). When I try to “Touch Focus,” I get a Touch Focus error (printed in red). Until that time, the TV was operating fine.

Considering the age of the TV, I have called a few local authorized repair shops, but am skeptical about having them come out, as the diagnostic fees are fairly expensive, and I am unsure if it would be worth getting it fixed… but cannot tell because I cannot get an estimate until they come out. So I figure it time to put my somewhat dated electrical engineering degree to work :bigsmile:

Earlier today I removed the board with the convergence ICs, and didn’t see any visible burned components…. And I also didn’t get shocked, which I was pretty happy about.

1) From attached pics (pic 1 and 2), does this indeed appear to be a convergence issue? I read something on a message board about a shorted yoke, which makes me wonder if I am going down the correct path.

2) From pic3, Considering the placement of the vertical block (kind of looks like a tuner), I am unsure of how I can unscrew the STK ICs from their respective heatsinks.. and then how to cut the pins… Perhaps this is outlined in the service manual, which I don’t have

3) And finally, another concern is that the PCB holes are not directly aligned under the ICs to be replaced (pic 4). They all have very precise bends. Are the STK IC pins a bit flexible?


Thanks for the great information that I have been reading. I'm feeling confident that once I get the correct service manual, schematics, and parts, I will hopefully be able to keep this TV out of the landfill.

-Greg
 

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Yes, this is a convergence issue. You remove the entire heat sink on these sets. The pins are flexible, and you have to make sure that they are very straight so that you can get the heat sinks and the pins to go into their holes at the same time. You also need to resolder any joints with ring cracks on the circuit board. Use the STK394-160 from the Hitachi kits and be sure to check the large resistors near the ICs while you have them out.
 
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Thank you for the quick reply. Looks like I may be on the right track. With regard to the STK394-160 ICs, I have been searching for them in Hitachi Kits. But all of the kits (X480302, X480301, X480295, X480293, etc) look like they come with STK392-150s. (at least from Tritronics). Are these acceptable, or would it be recommended to just purchase the STK394-106s individually?
 

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The original kits came from Hitachi with the STK392-150. I have not seen one with those from TriTronics in over a year. Some vendors may still have some with them, but I suspect that they have sold through. Just ask them and make it clear that you don't want the older chips. Not that it would be a problem. They were a better choice than the -110. The 394 series does seem to run a little cooler, however.
 
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Thanks for the information. I will call them today.
 
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So I got everything unassembled, the amps removed, and a thorough inspection for solder problems. So far so good.... Then I got to thinking that perhaps I should replace the big 12 resistors which are part of the STK circuitry. They are OMF 220 ohm and FR 1.8 ohm (Toshiba part Number 24383221 and 24547189). I tested them in circuit, and they are pretty close to nominal... I am unsure of the tolerances required, so I cannot really tell if they should be replaced. But upon looking at the backside of the PCB, there are already several post-production modifications. One is an added resistor in the STK1 circuit (pic6).

Is is normal for post-production mods like this (pic5)?

But the bigger question is... would it be advised to change out the resistors?

Thanks!
 

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This is normal. I do not change resistors unless there is thermal damage (discloration), the measure open, physical damage, or recommendation by the manufacturer. Be sure to resolder ANY connections with ring cracks on that circuit board.
 
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Discussion Starter #8
Thanks. I haven't found any ring cracks, but I have reheated many of the pads (especially along the board-to-board connectors) to ensure if there were any hairline cracks, the reheating would hopefully have taken care of them.

And finally, the kit I ordered has STK394-160E amps... I hope the "E" doesn't make a difference.

I will let you know of my results!
 

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The "E" suffix simply means lead free.
 
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I want to say "Thank You" for your advise.

I received and soldered in the parts yesterday. I had to play around a bit with the convergence grid in the service menu, but TV seems to be working fine and the picture looks great!

Thanks Again!

Sincerely,
Greg
 
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Discussion Starter #11
Hi Greg,

Where did you order the kit for the STK394-160E's? I have what I think to be the exact same problem with my 61H71.

Thanks a lot!

-Tim
 

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thanks, Should have checked out the stickies first, had no questions other than that. I'm really glad this forum is in place, after reading the post I know this will be an easy fix.

-Tim
 
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Discussion Starter #14
Tritronics (Miami)

PM me if you would like me to email you some pictures of the process
 
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Discussion Starter #15
Hey WannaTheater thanks for the tip. I ended up buying some sanyo stk394-160 chips from a dealer on eBay, and they seemed to be legit. I opened up the TV and just started disconnecting and unscrewing whatever it looked like i needed to, desoldered the heat sinks and chips, popped in the new chips, and now it's fixed! some thermal grease is definitely needed for the sink-chip interface, of which I obtained some leftover from a CPU package. Thanks so much for posting this topic originally and everyone else who replied for the help.

-Tim
 
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Discussion Starter #17
I want to thank everyone in this thread. Using the information posted here, I was able to fix my Toshiba 61H71. I had the same convergence problem. I did not upgrade my STKs, I stayed with the 392-110s and had to replace just one resistor. Fixed it just in time to watch my Sooners lose!
Thanks again.
 

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It was a great game. Of course, it looked much better from the Gainesville point of view, even for an LSU Tiger fan.
 

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hi im new to this whole tv thing. i just picked up this same tv for free on the side of the road, i saw the guy put it out and i grabbed it. My tv is having the same problem so i started taking the back apart. Im stuck on how to take the right side off. The bridge connectors ( i have no clue ) and then how do i take the heat sink off? you keep talking about Hitachi kits where do you find them? thanks a lot.
 

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Start a new thread, post the model number and specifics about what you are experiencing, and read the convergence repair sticky, at least the first ten posts very carefully.
 
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