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Circuit ICs were heated and blow now I need a replacement.

Tda7295
tda7265
L7809cv
full details and guidance is required
the last mentioned IC heats up too much.
Any alternative ICs.

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When you try to turn the tv on, all you get is a blinking red light, if you unplug for awhile, sometime it will come on.


Symptom: tv turns on, tv clicks once, red light comes on. Then, tv either works for a while, followed by a click, no video, normal sound and flashing red light; or, tv immediately clicks, no video, no sound, red light flashes. If that is the problem, you need to replace the convergence ICs. I had to do this twice. The two convergence ICs are mounted on palm-sized aluminum heat sinks. The heat sinks are soldered to the main circuit board. There are 4 pins soldered to the board for each heat sink, and 18 pins soldered to the board for each IC. Some of the heat sink pins are a bit difficult to desolder. The pins for the ICs are not difficult to desolder, but you must be careful not to overheat them. The heat sink and the IC come out as a unit, after all pins are desoldered. The IC is screwed to the heat sink. The correct replacement IC is a Sanyo STK392-110. I got mine from B&D Enterprises. They were not expensive. The new ICs need to be mounted to the heat sink with a heat transfer paste. I used Arctic Silver from my computer processor heat sink. Installation of the heat sink/IC assembly is a bit tricky, since you have to align all 18 IC pins and the 4 heat sink pins. When all the pins are visible through the holes in the circuit board, resolder everything. The TV should now work. Be sure to replace both ICs. My first repair was done by a technician, who obviously only replaced one. That repair only lasted a couple years, before the problem returned.

Mar 22, 2011 | Toshiba TZ55V61 55" Rear Projection...

Tip

How to find and replace a defective vertical IC.


When your TV works, has sound, good indicator light but all you have for a picture is a horizontal line across the screen, you have no vertical drive. This can be caused by the IC overheating or a power spike. In addition if you have a newer TV (projector) it may not turn on and will only blink an error code.

This is not a difficult fix but requires patience, good soldering skills and dilligence. Begin by unplugging the set and removing the rear lower area. Around the perimeter of the section you will see screws. Some will have arrows pointing at them. Remove all these screws and remove the rear cover.

Now you should be able to see the entire chassis. It will be mounted on a plastic frame and will consist of two or more circuit boards. The one, usually on the left, will be a small signal board. The one on the right will be the low voltage power supply, high voltage power supply and you guessed it, the vertical drive section.

The vertical IC is located near where the wires from the yoke which are red,green,yellow and blue terminate on the main board. The yoke is a large coil on the rear of the CRT which spreads the beam. It is slid over the glass CRT. Follow the wires (which should be green, yellow, blue and red to the circuit board. This will be the vacinity of the vertical IC. It will be mounted to a large heat sink and generally the designation begins with "LA" followed by 4 numbers. Panasonics generally begin with TDA.

Once located, remove and replace the unit. Removing the unit will probably require removing the circuit board. This involves removing all the screws around the perimeter of the board and any which you find in the center of the board. Do not force it, if it will not move easily look for and remove more screws.

You can get the replacement parts at http://www.encompass.com . Make sure you clean off the old heat sink compond and reinstall new heat sink silicone also available at the same web site. The heat sink compound facilitates heat transfer to the heat sink and keeps the IC cool. Generally the ICs are run at a high output and get very hot.

After replacement of the IC check all the safety resisters near it for continuity and also any and all diodes for integrity. These parts would be in the vicinity of the heat sink. Removing the IC may require prying it off the heat sink as many times the heat sink compound acts like a glue.

If everything checks ok you should have a working set.

If you do not have vertical drive, you will need a schematic to find the power source for the IC and test the circuit to see if it has the proper voltages.

You can sometimes get schematics from http://www.encompass.com but they do not have all of them. If you do not mind paying about $16.00 US you can get any service manual from http://www.servicemanuals.net .

Once the proper power is supplied to the IC you should have a working set.

Remember to use an isolation transformer anytime you are going to check voltages in the set. Modern TVs have the chassis attached to neutral making a 60 volt difference between the chassis and hot side. This means that if you do not use an isolation transformer and apply a DVM with a low path of resistance you will cause a direct short and blow the fuse, if you are lucky. Also remember to be careful when measuring voltages as there are lethal voltages in a TV when plugged in and running.

Thanks for using FixYa and for the great rating.

hardrocko

on May 11, 2010 | Televison & Video

Tip

How to change projection TV convergence ICs.


NOTE: THIS PROCEDURE DOES NOT APPLY TO RCA CHASSIS MODEL ITC222. FOR THAT MODEL CLICK HERE.


When the picture on your projection TV looks like 3D, the image bows in on all sides and red/green/blue are separated you have bad convergence ICs. They are located on the mainboard attached to a large aluminum heat sink. The heat sink could be shiny or black depending on the manufacturer. They are generally located near the rear of the High Voltage/Power supply board. The ICs are shaped like a trapezoid. I have a picture of one at the end of this tip. It is for identification purposes only, your actual part number may be different. Make sure you get the correct units.

Once you have located the ICs and heat sink look at the numbers printed on the ICs. The numbers on them should be of the form STK392-XXX. Note the number and go to http://www.encompass.com and order two. One is for horizontal and one is for vertical. You should also go to http://www.mcmelectronics.com and if you do not already own one order a good solder iron (40 watts with conical tip, temp control would be helpful), solder wick, heat sink compound, solder puller and solder.
You will need good soldering equipment and skills. Do not apply too much heat to the connections on the underside of the board or the lands will come off causing bigger problems. The secret to soldering/desoldering is to have a hot iron and concentrate on one part at a time. Keep good contact with the piece being soldered/unsoldered.

In addition you must have a clean tip to do a good job and get the soldering done in the shortest period of time. Use a good tip cleaner (looks like a kitchen scrubber) which can be purchased at the site I mentioned or a substitute you may have, steel wool or a damp cloth. All work about the same, the important part is that the tip is kept clean.

Sometimes you need to remove the heat sink to install the IC's leads due to the number, and difficulty, of getting them in the proper holes. This usually requires removing several screws from the bottom of the board or unsoldering the hold down tabs and possibly straigtening them to get them through the holes in the circuit board depending on your particular model. The ICs can be removed from the heat sinks by removing two hold down screws and prying them loose from the heat sink. This can sometimes take quite a bit of pressure.

Another problem to watch out for is bridging of the leads when resoldering the IC into the board. Before powering up the unit make absolutely certain that no leads have been soldered together or "bridged". Correct any issues. You do not need a large amount of solder on the leads. A nice round smooth connection is best. Look at some of the other solder joints to see what a good solder joint should look like.

If your eyes are like mine it would pay to purchase a pair of magnifying binoculars from the same site you can get the equipment from, http://www.mcmelectronics.com .

After replacing the ICs check all the resistors and microfuses in the area of the convergence ICs for opens. The fuses will look like resistors but no color code.

Remove the old ICs from the board and install the new ones. Be careful not to get the units too hot when installing the new ones. The heat sink compound goes on the back of the ICs in a thin coat to aid heat disapation. Don't over do it! Also clean all the old heat sink compound off the heat sink.

Once the ICs have been replaced and the unit is up and running you will need to set the convergence to align the beams. You should be familiar with this, if not the procedure should be outlined in your operations manual. If you lost your manual go to http://www.retrevo.com to get a new one for free.

If this was the only problem your unit should now look fine. While you have it apart you should clean the lenses and the mirror with a soft lint free cloth and window cleaner (no ammonia). Always spray the cloth, never spray inside the TV.

If the lines still will not converge you have a bad digital control box. Detailed intructions for removal and replacement of the digital box are located at my tip http://www.fixya.com/support/r4273935-replace_digital_convergence_box .

8520202.jpg

Example of a convergence IC. Your part # may be different.

Thanks for using FixYa.

hardrocko

on Feb 27, 2010 | Philips Magnavox 9P6034C 60" Rear...

1 Answer

Television has double images like 3D, and bottom half of screen has a concaved image.


Hi,
Please replace convergence ICs in tv, there are two big black ICs that has number STK392-110 mounted with big aluminum heat sink, replacement these ICs will solve your tv problem. Also check big resistor nearby these convergence ICs and replace if found burn mark or color faded.
On circuit board, IC location number is IC7001 and IC7002
Let me know if you have additional question.
Thanks.

Dec 25, 2010 | Panasonic PT-47WX49 47" Rear Projection...

1 Answer

I have a 53 inch hitachi ultravision #53UDX10B Its out of focus and when you press the magic focus button it trys then pops up with the # 4 in the corner is this a convergence problem or what ?


Yes, you have a convergence failure. Usually requires replacement of 2 X STK ICs and any burnt resistors associated with the function that is faulty.

Look at the user menu and compare with images on our Convergence Gallery. Try to adjust in the convergence adjust menu. Identify the functions that do not work and make note. When you replace the ICs, pay special attention to the low ohm resistors for the non-working function. They will be located near the colored plug associated with the non-working function. If red vertical will not adjust, check resistors near the red plug.

There are many posts and websites that offer "new and improved Convergence IC substitutes. My advice is to use the original part numbers and replace any burnt resistors with original values. Many ICs purchased on the Internet are very poor quality and do not work. Many users get substitute replacement ICs and never get their TVs working again.

If you have other electronics repair experience, this job may be done with some chance of success. If you have no experience, there are many secondary problems that can and usually do appear. Determining how to fix the secondary faults and how to correctly align the TV is difficult without prior convergence repair experience.

Some of the common problems encountered are:
1. Poor solder techniques, resulting in damaged PC boards or poor solder connections.
2. Poor quality or wrong parts installed and recognizing this problem.
3. Resistors open or burnt. Some resistors are weakened by the initial faulty IC. Replacing with a "good" IC and starting the TV causes the weakened resistors to burn up. IC may be ok but there are one or more open resistors that measured ok when ICs were being replaced.
4. Wrong ICs used, causing resistors to burn up.
5. Resistors that measure normal and become faulty when heated by current flow.
6. Recognizing that convergence circuit is repaired correctly and alignment is needed.
7. Major alignment in service menu required because data is corrupted by multiple tries of magic focus or manual adjustment while faulty circuit conditions exist.
8. Major alignment required because user adjusted centering rings or physically changed mechanical focus adjustment, then mis-adjusted convergence settings trying to correct mechanical alignment faults.
9. User has not connected plugs and connectors correctly and caused secondary damage or mis-alignment trying to correct secondary issue.

Physically replacing the ICs may appear simple but recognizing if a fault still exists or if correct repair is required causes many attempts at repair to fail. Keep it simple. Replace with good quality original part numbers, measure suspect resistors and adjust only what is necessary.

There are only 3 things to fix, IC failure, resistor failure and user induced secondary faults. Data processor and memory is bulletproof.

easyab

Apr 22, 2010 | Hitachi 53UDX10B 53" Rear Projection...

2 Answers

Tv turned itself off. turn power back on, picture


Your TV is experiencing a convergence issue as indicated by the 3 blinks. The only way to fix this is replacing the convergence ICs. It is not a hard task to replace these ICs. You just need to know how to solder and work on printed circuit boards.

The convergence ICs are mounted on a large heat sink and are marked with codes starting with the letters STK and there are two of them. You need to replace both.

Look for the heat sink with two ICs mounted on it and check the markings.

Once found, cut the IC legs with a small side cutter and unscrew it from the heat sink. Remove the legs left soldered on the board.

Take note of the IC markings for ordering the right part and how it was installed. Don't forget to buy along with the IC a thermal compound.

Check the pico fuses on the same board. Most likely you will find a blown one. These fuses look very much like a resistor, not like the usual transparent fuse, and usually yellow.

Once you have the replacement ICs, put it on the board in the same way as it was installed before. Make sure the screw holes are aligned before soldering the legs into the board.

Put a reasonable amount of thermal grease/compound between the ICs and the heat sink and fix them with the screws.

Double check the board for any splash of solders that might cause a short circuit and damage the board.


Dec 07, 2009 | Panasonic PT-47WX53 47" Rear Projection...

1 Answer

Sony kp 46wt500 has 3d screen what might the problem be?


If convergence out ICs got defective then TV shows that kind of picture.
Replace IC8001 and IC8002 on D Board, both big black ICs are mounted on aluminum heat sink and number STK392-560 would be written on it.
Required ICs are available in Part Store, click that link to see an image of IC and price info.
If you are not comfortable with soldering parts in circuit board, call local tv tech to replace it.
Thanks.

Nov 13, 2009 | Sony KP-46WT500 46" Rear Projection...

1 Answer

I have a toshiba TP55C81 projection TV. The red The red vertical adjustments stopped working. The adjustmnet knob in the control panel does not effect the adjustment and none of the vertical adjustmen


You need to replace the vertical STK convergence chip but I would recommend that you replace the horizontal chip at the same time as this is likely to fail soon.

The following relates to the repair I have recently carried out to my Toshibal 40WH08B rear projection TV but shuold be very similar to your model. Replace the STK chips with the same type on your model:

On the convergence board PB 9487 (the one with the 2 large heat sinks that the r, b & g guns plug into) you will see two STK392-110 ics connected to the large heat sinks. Replace both of these and readjust convergence in service mode if necessary.

I obtained the replacement ics from Charles Hyde & Sons Ltd (see link below). I ordered the general ics not the Toshiba ones as these are identical as far as I could see and they cost £17.19 each instead of £36.68 each.

http://www.chsinteractive.co.uk/search.html?query=stk392-110

You will need to desolder the heat sinks as well as the ics as access to the ic mount screws are obstructed by the conv.dig board (metal cased). Buy a good quality desolder pump if you dont have one.
One last thing I should mention. The white paste between the ics and the heatsink is silicon thermal compound. Without this the heatsinks will not take heat from the ics effectivly and the ics will burn out! I recommend that you clean all of the old paste off the heatsinks and apply new to the whole of the metal plates on the back of the ics before you screw them to the heatsinks. You can get the thermal compound and the desolder pump from the same supplier I recommended for the ics.

Let know if your are having any problems.

May 30, 2009 | Toshiba TP55F80/81 55" Rear Projection...

2 Answers

Where can we get the best IC Replacement


always stick with the manufacturers brand ! but you will need to check the resistors on the IC lines to make sure thier values are not off , because that will cause the IC to go again no matter what brand IC you use. other components in line of the IC should also be checked for bad values as they can also cause malfunction and breakdown of an IC and its circuit components

Dec 30, 2008 | Panasonic PT-53TW53 53" Rear Projection...

1 Answer

Toshiba big screen The tv is like double exposed . I have a toshiba big screen tv and I have double images in red and green. How do I fix this problem?


This is likely your convergence ICs(chips). If you can bump it then the ICs (chips) are still ok, it just needs resoldering.
my company charges $300-400 for the full repair (replacing ICs, full realignment plus cleaning)
if you can find a company that will resolder for you, it could cost $100-200 maybe. if you are a handy person with soldering skills, you could repair yourself. i can instruct if needed, but convergence IC soldering requires decent soldering skills. you will find the ICs on the largest heatsink in the tv. the part number starts with STK. if you replace them, check the resistors in front of them and replace accordingly. most toshiba will blow up to 3 fuses (f850, f851, f852)

Dec 08, 2008 | Televison & Video

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