Unknown Toshiba 42H83 Problem

[sosuke]

I had thought it was convergence, but it seems those dealing with convergence had much smaller issues than this. I took a video of what the picture looks like coming through cable, its a little better thru the component inputs. I have tried all the inputs from multiple different sources and its the same effect. What kind of problem is this?

http://www.youtube.com/watch?v=5TmC8udafPst

[sosuke]

Re: Unknown Toshiba 42H83 Problem

Seems I can't edit my post, the youtube URL looks wrong:
http://www.youtube.com/watch?v=5TmC8udafPs

[kc8adu]

Re: Unknown Toshiba 42H83 Problem

open filter on high b+?i cant tell if that is camera overload or smearing on the set.
i see lots of jaggies in the image like unfiltered supply to h-out
looks like time to poke about with the scope probe!

[kc8adu]

Re: Unknown Toshiba 42H83 Problem

btw i wont install any flash crap player.
post the .avi

[sosuke]

Re: Unknown Toshiba 42H83 Problem

the picture is clear, thats the set, ill post the avi when i get back home tonight

[Wizard]

Re: Unknown Toshiba 42H83 Problem

Bad capacitors in the hyper module, the big upright box behind the input panel. Involves swapping all 10uF 50V SMD electrolytics, 11 of them. Have a tech do it if you are not able to. And tell the tech this, very involved job as have to pull the small signal mainboard out (tricky with some wires plugs that is hotglued), unsolder 4 tabs then pull hyper module out, unsolder another 4 tabs holding lid on and start swapping those tiny SMD caps as I montioned.

Cheers, Wizard

[Krankshaft]

Re: Unknown Toshiba 42H83 Problem

100% correct. I had to to this to my Toshiba 42H82 in August.

Now the convergence ICs went on it and took a resistor with them.

This TV is really testing my patience .

[Wizard]

Re: Unknown Toshiba 42H83 Problem

chuckle... Get pair of new STK392-0x0 and 2W of that value resistor and dig in.

But you need service manual to adjust the convergence after this job and be more careful on this toshiba. I had one lose all the adjustments when I rolled over from one end of service menu to back to beginnng. :O

For this reason, I have "bad attitude" towards toshibas.

Cheers, Wizard

[Krankshaft]

Re: Unknown Toshiba 42H83 Problem

Yup I already ordered the parts.

Removed the old ICs and cleaned off that old white junk thermal paste.

I will use Arctic Silver 5 on the new ones.

The STK 392-110s were the WORST series of convergence correction ICs that Sanyo ever made. Very unreliable.

I am upgrading to the newer STK-394-160s. They come in a Hitachi kit 37 bucks for both of them.

I only buy from Tritronics an authorized distributor for Toshiba and Hitachi since there are counterfeits / rejects floating everywhere on the Internet.

Unfortunately they didn't have the metal oxide resistors in stock and there was no way that I'd wait a week and a half special order for those.

So I ordered them from Newark. I'll have the ICs today but have to wait till tommorrow for the 2W resistors .

I'm not a fan of the service mode either.

Why did they have to use hexidecimal? I would have been just as happy with ordinary numbers. And those stupid abbreviations HIT, POS, etc come on Toshiba thank goodness for the service manual.

Here's an idea how about 1 to 100 .

I have a convergence overlay and service manual from Toshiba so touchups won't be a problem.

[Wizard]

Re: Unknown Toshiba 42H83 Problem

ones i can get is STK394-250E.

No -160's.

Sigh. Cheers, Wizard

[Krankshaft]

Re: Unknown Toshiba 42H83 Problem

The series you mention 394 is good the prefix afterward STK-394-xxx is for your individual sets convergence design. It varies from set to set.

Some ICs have 3 onboard amps or 6 it depends on the sets design. Also different variants have different muting designs and power ratings again unique to each set. They use those last 3 numbers for that purpose.

The old 392 series is the junk.

Oh yes and in case your curious the E just means lead free.

[technicolor]

Re: Unknown Toshiba 42H83 Problem

Hi there,

I have 42H83 toshiba. I had both these problems, first one was fixed by best buy as i had warranty but this time i had to do my own search. Please confirm if it is convergence problem.

Few days ago suddenly red hsade started appearing on the right side, right side shows two pictures, one is original picture and second is the shade of red. Is it convergence problem. If so should i be ordering STK392-150 or the higher model like your 394-XXX, can you also tell me these XXX values please?
Also the resistor model number etc and where is it located?

Also where can i find convergence overlay and service manual fro Toshiba.

Thanks

[Krankshaft]

Re: Unknown Toshiba 42H83 Problem

Well you will need to replace both STK convergence ICs with new ones.

You will also need to replace an open 1.8 ohm 2 watt metal film resistor.

Using your multimeter measure the large 1.8 ohm resistors near the convergence ICs odds are one of them is open.

Make sure that you buy metal film resistors and NOT carbon film because if a carbon film resistor shorts out it can catch fire.

You can buy the resistors from any electronics supplier like Newark.com or Digikey.

You can get the ICs and convergence overlay from Tritronics they sell legit ICs and not the counterfeits or knockoffs (which don't work) being sold for $10 bucks a piece.

http://www.tritronicsinc.com

Yes you can upgrade your ICS to STK-394-160E. The E just means that it's lead free.

You can buy two of them in a set for less then one in this repair kit.

The kit is for Hitachi sets so the resistors won't work on your set but its a great deal.

http://www.tritronicsinc.com/storefr...&itm_id=567178

As for assistance on servicing check out this link:

http://www.hometheatershack.com/foru...e-repairs.html

[Krankshaft]

Re: Unknown Toshiba 42H83 Problem

In addition to that be sure to clean off the old thermal compound with rubbing alcohol and apply new compound. Most computer and electronics stores will carry this white compound in a tube.

Apply a small dot to both the back of the IC and the heatsink then smooth it out with a straight razor.

After you're done apply the IC to the heatsink lining up the screw holes then while applying light pressure rock it back and fourth to mate the IC to the heatsink. Then secure the screws don't overtighten or you could crack the plastic IC package.

After the repair is done the convergence should return to normal you will probably need a minor touch up at best since the new ICs will have slightly different tolerances.

After you're done check out the picture if you need to get into service mode to adjust the converence let me know and I'll give instructions so you don't need to buy the service manual.

I sincerely hope that when the guys fixed your hyper module problem that they replaced the 10uf caps in the module and didn't just swap it out for a new one.

If they just swapped it out be ready for another failure because that new unit has the same crappy caps that failed in the first place.

[chipper]

Re: Unknown Toshiba 42H83 Problem

I would be tempted to change the main power supply transformer first , since it really could be interference from the winding , and or the filters as a result. Like you have full power that's been shorted or shorting right before your eyes.

That would also make it so that any future replacement parts would work that much better or longer without any adverse reoccurences. Being a big set , if the main supply is small or relies on a single unit , I would start there and expect to see some change as a result before changing anything. The fact that you get different composite or component picture suggested to me that it may be power supply. The source , because at lower resolutions there is a difference in signal strength.

When the main source is faulting , slightly , the rest of the system is not designed to do anything to correct it.

[Wizard]

Re: Unknown Toshiba 42H83 Problem

Actually your power transformer suggestion is unfounded.

Either it makes noise(whining, high squeal or high buzz) or blow the power supply IC (Toshiba uses a STK IC for this.). And I have seen the noise onto the picture when a HV component is acing, sometimes audible but the picture is not like this. It's more of sharp interferance than the wide bands of fuzzy noises. Almost similar to someone knocking or playing with the cable on a analog tv.

The problem lies in the hyper module bad SMD electrolytics. I have done several of these. (xxH84 series) that use same chassis. Once I had to replace a IC due to
intermittent black and white issue.

Cheers, Wizard

[chipper]

Re: Unknown Toshiba 42H83 Problem

Actually your power transformer suggestion is unfounded.

Either it makes noise(whining, high squeal or high buzz) or blow the power supply IC (Toshiba uses a STK IC for this.). And I have seen the noise onto the picture when a HV component is acing, sometimes audible but the picture is not like this. It's more of sharp interferance than the wide bands of fuzzy noises. Almost similar to someone knocking or playing with the cable on a analog tv.

The problem lies in the hyper module bad SMD electrolytics. I have done several of these. (xxH84 series) that use same chassis. Once I had to replace a IC due to
intermittent black and white issue.

Cheers, Wizard

There is nothing "unfounded" in expecting that if the main transformer is not producing clean and normal power at the source , that other things will not be effected no matter what type they are. I don't know how many threads I have read now that show that replacing the IC's has only worked temporarily , since the same symptoms (usually not converging) , come back.
Or , the set get's worse by not turning on at all. You have your opinion and I have mine. Just because a power supply is producing the correct voltage , doesn't mean it is ok.

[Wizard]

Re: Unknown Toshiba 42H83 Problem

Is that true? That's most unusual failure. Usually you would hear the windings arcing when it is messing with the waveforms. And when this happens, this usually takes out the transistor/FET out really quick. A shorted diode on the output will do this same unless the IC is best design that senses overcurrent/undervolt sensing and protect itself.

I had bad windings in flybacks and yoke take out the transistor in one cycle as well. POP.

Cheers, Wizard

[Blue Flame]

Re: Unknown Toshiba 42H83 Problem

Hi, Guys. I'm new here; just been kind of lurking around for a while, but I saw something here I thought I'd comment on.

Regarding the STK392-110 ICs: I agree they are a huge headache, but I also blame the TV makers. If you check the datasheet for the IC you'll see that in addition to being good for only 3amps, it is rated at 15 khz. (others in the series are rated at the same frequency) I think part of the problem is that these HD sets are churning out 2h or 2.1h scan rates and they're using an IC that is only rated for 1h. I have never figured out what they were thinking when they did that. Kinda like overclocking your CPU by 100%...you'd better be able to immerse it in liquid nitrogen to keep it from going up in smoke.


For the -150 and below, I've been using the kits from Hitachi (X480293 or X480297) which has the 2 STK 394-160 plus a bunch of resistors, which come in handy for a lot of other things if you don't need them to finish the convergence job.

I started using these kits after I got burned by some "ORIGONAL SANYO" STK-392-150s that failed 3 times in the same set inside of a month. I was considering retiring from TV and getting a job flipping burgers at McDon@!d$ since it seemed I'd lost my touch. Then I found out about the fakes that had found their way into the supply line and started using the kits. Several hundred kits later, not one callback on a convergence job. I won't be flipping burgers after all.

BTW, as long as I'm here, I HATE that hyperboard!

Enough of my ranting....Great forum guys. Thanks.

[RobCX3]

Re: Unknown Toshiba 42H83 Problem

My 42H83 had this exact issue - replaced all 11 10uF caps on the Hyper module and have a perfect picture again. Thank you Wizard!