Question about Toshiba 55H70 55" Rear Projection Television
My TV was working fine then today the color went nuts, image is shaking, bending, ghost, and multiple lines are seen. After about 3 minutes, the power LED began to blink then the TV is shut off. Based on some of the postings, it seems like the problem is the convergence IC. I opened the back of the TV and saw STK392-110. I did a search on the net for the parts and found some IC with STK392-110 and some with STK392-110T. Questions 1. Can someone confirm that this is the convergence IC problem? 2. If so, are these ICs STK392-110 and STK392-110T the same chip? If not which one should I get? Thanks, /Dara
Based on your post above it sounds like the chips you tried were knock offs and not original Sanyo chips. They will look almost identical but the knock off chips will only last a month or two.
Here are some of the most common symptoms of a convergence problem.
Using your original remote go-to the tv settings then goto the convergence section.
Try to adjust the red and then the blue convergence.
You should be able to move them up, down, left, and right.
If you can't move them in all directions your convergence chips are bad and should be replaced. This is a common problem.
You need to replace the convergence chips and convergence resistors. Check the site www.TvRepairKits.com. They have put together a kits for most models. If you don't see a kit for your set send them a quick email and they will put one together for you. Their kits includes photo instruction guides, original Sanyo STK chips, convergence resistors, pico fuses, etc.
Posted on Feb 05, 2009
Thanks for the input Replaced the STKs and did a service mode convergence and the TV looks like new. Only goofy thing is that we had to go back and forth between the "end user convergence" on the menu and the "service mode" convergence a couple of times to get things dialed into range. No problem with the fuses or caps.
One thing we realized is that carpet under these units plugs the large vents under the main circuit boards ....it may not be a design issue after all, rather it may just be a thermal related failure (as some indicate). We stuck a piece of black colored plywood (so that you can't see it) under the set large enough for all four feet to push down the carpet pile. Hopefully the thing will last this time. ...Funny, but in Japan, carpet is not used much, but in the US we use it lots .....another translation problem???
Posted on Nov 24, 2008
I agree with engrx2's comment about the carpeting blocking the vent holes on the bottom of the set. I've been taking electronics apart for over 30 years, and I have never seen such thermally stressed, brittle plastic like I did when I repaired my sister's Toshiba (by replacing the convergence ICs).
If you have a similar TV set, and it's on carpeting, I'd recommend putting a metal plate or wood under the TV's feet/wheels to ensure that you can see underneath the TV from front to back. Even the Toshiba's user's manual, which mentions rear ventilation, does not say anything about the importance of bottom ventilation for this design.
Posted on Feb 22, 2009
If you are removing a defective chip, can you just cut the pins carefully with a wire cutter and later apply heat to pull them off?
Posted on Jan 29, 2008
I have what i believe is the ic convergence problem but want to verify with the group. The Toshiba 55hx70 TV will run for a while, then the top and bottom of the picture starts to bow bad and the picture looks likes its having a scanning problem then it shuts off with red power light blinking.
However its weird because the TV will stay on for 10 or 15 minutes without a problem then it goes into the problem state - sometimes MUCH longer. Seems like once the TV starts to heat up (15 minutes+) it starts to have the problem. Other times it will run for hours.
At this point the TV is 11 years old and i'm ready to go for broke and start replacing stuff to see if i can fix - otherwise i'm going for a new flat screen.
Any ideas as i was going to start with the ic chips? Does the above sound like a IC problem or a solder problem somewhere else. Maybe after 11 years the vents are plugged with dirt and i have a ventalation issue??? Suggestions????
thanks a lot everyone.
Posted on Apr 22, 2010
Checking back to see if the repair kit solution above worked.
Posted on Feb 19, 2010
I know this is an old post but i like to add my 2 cent's. yes your ic's was bad and the 1st set you put in eaher was new def or the stk392-110S you put in the set did not like :) anyway the next set wsa right it worked but i bet you forgot to clean the heat sink and add new heaksink compound thats why it wsa shuting down after afew Hr's and then burnt out agen. i hope you did not give up or messed around with anything eles it was and is the IC's just add the compound next time
Posted on Feb 15, 2010
So, are the 180's totally compatible for replacing 110's?
Posted on Dec 26, 2009
Posted on Jan 31, 2008
I too have replaced the IC's and it worked out fine. I used stk392180's. The 180's are rated a little higher, run cooler and are a direct replacement in my experience. By the way...anyone that has decided to scrap a 55h70...I am in desparate need of a speaker grille for mine. Please email me if you are discarding parts or have some for sale. [email protected]
Posted on Jul 11, 2007
TO DOIT YOURSELF IF UR NOT GOOD AT SOLDERING, THIS MIGHT BE UR PROBLEM, MAKE SURE THEIR ARE NO COLD JOINTS WHERE YOU SOLDERED THE IC CHIP PINS TO THE CIRCUIT BOARD, ALSO MAKE SURE YOU DID NOT MAKE A SOLDER BRIDGE BETWEEN ANY OF THE SOLDERED PINS. SOLDER CONNECTIONS MUST BE NEAT AND CLEAN, AND HOPEFULLY YOU USED THE RIGHT SOLDER FOR ELECTRONIC WORK, GOOD SOLDER CONNECTIONS SHOULD APPEAR EVEN AROUND PINS, AND SOME WHAT SHINNY. USE A TOOTH BRUSH TO GENTLY REMOVE ANY EXCESS FLUX OR LOOSE SOLDER FROM BOARD. GOOD LUCK DAVE
Posted on Jul 09, 2007
Heres what said about the stk392-110 Product Details: The STK392-110 is a convergence correction circuit IC for video projectors. It incorporates three output amplifiers in a single package, making possible the construction of CRT horizontal and vertical convergence correction output circuits for each of the RGB colors using ust two hybrid ICs. The output circuit use a class-B configuration, in comparison with the STK392-010, realizing a more compact package and lower cost. The only differance i was told is one the stk392-110 was made in japan and the stk392-110T was made in Japan Its a hard call if your problem is a IC problem related to the convergence IC's or a capacitor problem in the sweep poer supply? Onlt rel way would be to trouble shoot the set as shot gunning parts can be an expensive propisition.. if you have no electronic skills along with soldering skills themn please remember the High Voltage safety issues involved with a TV set . Please seek out a pro to assist you with this repair. good Luck
Posted on Aug 04, 2006
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