Question about Legacy Audio American Legacy II LA290 Car Audio Amplifier

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No power plug amp up but no power. i`m wondering could it be the two power ic`s located on the heat sink

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Check the unit for any Fuses, Fusable Links etc, if they are OK proceede on to testing, I often troubleshoot these issues via a stereo head set, modify the leads so you can "Touch" them onto the Speakers Output Terminals, connect the "Shields" together, thats "Earth" and the other Two, are Left & Right... with a Sinal feed in & the Amp's volume turned to about 25% volume, connect up the Earth wires to the Chassis with a clip, under a srew etc, just make good contact... then touch the Left & right wires onto the output, ya should hear sound... if not most probably the Output device(s) may have gone faulty.

Posted on Aug 08, 2007

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1 Answer

Good day i have a Technics amplifier SU-X320. Problem is it powers up up there is no sound. Checked all basic fault finding, suspect it is the volume IC.


"Volume IC" do you mean an IC that is a pre-amp and controls the volume and things like tone? Or do you mean the main power amp IC, which will be on the big heat sink?
If you amp uses the latter and not individual separate devices for the power amp, suspect that over the other IC. But if the amp has separate power amps for both channels, replace the IC.

Oct 09, 2013 | Technics Audio Players & Recorders

1 Answer

Kd-46wt500 sony big screen colors dont line up is projectors goin out picture on tv is blurry pic looks stretched out as well


Can you verify the model number and see if its A KP46WT500 model? If so chances are just the convergence Ics ( stk 392-560 ) and pico fuses are the problem. There are 6 3.5 amp pico fuses directly beneath the heat sink fins on the D board ( where the Convergence ICs are located) Check those six pico fuses and also two 5 amp picos on the G board ( where power cord plugs in) if any of the picos on either board are open then the Convergence ICs will require replacement.

Sep 26, 2011 | Sony KP-46WT500 46" Rear Projection...

1 Answer

Power tv on and then it clicks and turns off


Most of the time there are one or more 5 amp pico fuses open on the power supply. The cause of them opening is the +/- 30 volt line shorting from the convergence circuit. If you take this repair on yourself and are familiar with a ohm meter, you can check the small green pico fuses in the power supply. Remove the power from the set, take the back off. The board in the center is the power supply and convergence circuit. In the center of the you will a transformer. Just to the left of the transformer you will small green fuses that look like resisters. They are marked on the board but are sometimes hard to see. If one is open for the 30 volt line, the convergence IC's need to be replaced. They are mounted on the back of the large heat sink and the board must be removed to replace them. When you remove the board, be sure to remove all the screws not only around the edges of the board but also in the center too. There are also screws on each end of the heat sink and on the blind side center foot securing a ground wire. On each side of the board there are plug clips that must be lifted. At the front of the board there are plug connectors that need to be unplugged. Once the board is removed the IC's are easy to replace. Remove them from the heat sink, Unsolder them from the board using solderwik. The Convergence IC's should be STK392-570. If there is only one, it is a STK393-110. When replacing them, I recommend using heat sink compound on the back of the IC's where they contact the heat sink. solder in the new IC's then attach the heat sink to them.
Replace the small pico fuse or fuses, they should be rated at 5 amps. Once all the parts are replaced, remount the board making sure the heat sink holes align with the board holes. Reconnect the plug connectors, Plug clips, and reinstall all the board screws.

I hope this helps,
Skyassoc

Dec 12, 2010 | Mitsubishi WS-55809 55" Rear Projection...

1 Answer

Color distortion, wavy blue lines


This is caused by the convergence IC or IC's failing. If it has 2 IC's for the convergence circuit, they are STK392-540. If there is only 1, it is a STK393-110. The Convergence Board is the center board and also includes the Main Power Supply. Great care is needed when removing making sure that all the screws are are removed around the edged of the board, in the center of the board, and on the back side of the heat sink. You also have 5 plug clips that pull up, 3 on the left and 2 on the right. Please remove the power from the set before doing anything. Some times being over zealous, we forget these things. Once the board is removed, the IC' s or IC are easy to removed with solder wick. The heat-sink compound is messy so be careful not to get it on clothing or the rug. Make sure you remount the new IC's in the right direction and use heat-sink compound on the back of the parts to prevent heat from damaging the parts prematurely. once the parts are mounted, reinstall the board making sure the heat-sink lines up correctly and the center screw secured the green ground wire in the center position of the heat-sink. Reinstall the rest of the screws and reconnect the plug clips on both sides of the board. That should do the trick. I do caution you that this is not a quick job and do not rush through it. I hopefully covered all the steps for success.
Good luck,
skyassoc

Dec 09, 2010 | Mitsubishi WS-65809 65" Rear Projection...

1 Answer

I have a 65' Mitsubishi projecton TV Model WS-55859. It will not "start" ie: no sound or picture. I hit the reset button and the green light flashes for about 1 minute. I then wait about 1...


Dean,
Most of the shut down problems with this model series are caused by the convergence IC's failing
causing one or more of the 5 amp micro fuses to open. These are located on the power supply board centered in the middle of the chassi. These micro fuses are small green componets, and kind of look like resisters. there are usuallly 5 of these and they are located left of the transformer. to check them, unplug the AC power to the set. Use a ohm meter and they will read open if they are bad. As far as the convergence IC's, they are mounted on the big heat sink also on the power supply board. You will need to remove the power supply board to replace these. Be careful to remove all the screws in the center of the board, around the edges, and on the back of the heat-sink. The IC numbers will either be STK392-540, or STK 393-110. Use extra care when unsoldering the old IC's to make sure you do not damage the solder pads. I do recommend heat sink compound being used on the back of the IC's to prevent premature failure. Radio Shack should carry some.
I hope this helps,
Skyassoc

Dec 08, 2010 | Mitsubishi Televison & Video

1 Answer

The Blue has developed an arc on the top and bottom


The KP51WS510 has the two STK392-560 ICs on the D board ( Brown Board laying flat on the left side) you will see the large heat sinks with the fins on it. The ICs are mounted to the heatsinks. In that model you will need to check the 6 Pico fuses right next to the heat sinks, and there are also 2 additional pico fuses on the G board ( where power cord plugs into) that will also need to be checked.

Jan 23, 2010 | Sony KP-51WS510 51" Rear Projection...

1 Answer

Hi. i have a 54 inch samsung rear projection tv. 2 years ago something happend within the tv and the picture was doubled. and there were red lines going through the tv. i had sears come out today and look...


Hi,
This sounds like the most common thing that fails on projection TV's, regardless of the brand. The convergence circuit has two, or sometimes three STK IC chips mounted on heat sinks to drive the convergence yokes. They typically last anywhere from 5-10 years, then they fail.

It sounds like in your case, the solder joints on the bottom of one of these chips may be failing and some fresh solder will make it go for a while. I would recommend you to replace both the STK chips.
These ICs are used to align and keep aligned the three colors on the screen...

INSTRUCTION TO REPLACE CONVERGENCE ICs:

The parts you will need are two ic's that are referred to as STK ic's. This is in reference to the first three letters of the part number. You will also need some pico fuses. The pico fuses are little yellow fuses that look like resistors. When they blow, they will show no physical sign of failure. The amperage rating will be printed on the fuse. For example a 5 amp fuse will have the number 5000 on it. A 3.15 amp fuse will have the number 3150 on it. You will need to use an ohm meter to test these fuses

The stk ic's are on the "D" board, attached to large heat sinks, When looking from the back you can see the heat sinks but the part's themselves will be pointing away from you and hard to see without removing the board, or using a mirror to look at the part numbers. The fuses are generally located under the fins of the heat sinks. There are several of them and vary by model. On the "G" board there will be two yellow pico fuses near the connector going to "D" board. These fuses provide power to the stk ic's you must check these as well.

When replacing the STKs make sure you use heat sink compound on the back of the ic's before installing them. Also as a rule of thumb, screw or clamp the ic's down to their heat sinks before you solder the pins. Replace any blown pico fuses and re- install your boards. When you turn your set on it may still be out of convergence due to many factors. Try pressing the auto focus button on front of your set.

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Rnj VINODKUMAR

Nov 11, 2009 | Samsung Televison & Video

1 Answer

Convergence amps


you need to change the ics that are located on the converge board is the one that is screw to the heat sink change both or the closes to the rear is for green vertical and horizontal and blue vertical and the one closes to the front is for the red vertical and horizontal and blue horizotal it starts with a STK number.

Jun 16, 2008 | Toshiba 55HX70 55" Rear Projection...

1 Answer

Akai pth 5498


Your Convergence amp ICs are bad. Heres how you fix It.
they are located on a huge heat sink inside your set. Just look for the largest aluminum heat sink inside your set. You will notice them they are large black ICs with about 16 pins on them. Just unsolder the old ones and solder in the replacements. just be sure to put some heat sink compound on the back of the new ICs where they contact the heat sink. You can get a de-soldering iron at radio shack with a rubber bulb to make the de-soldering alot easier and you will also need a low wattage soldering Iron to solder in the new ones. Just mark any wires you remove to get the convergence module out. That way you will know where the wires plug in when your finished. It will need a convergence adjustment when your finihed. Be careful not to bridge any of the pins with excess solder. Inspect the pins with a magnifying glass when your finished to make sure the solder from any adjacent pins arent touching each other.

Jan 06, 2008 | Akai PTH5498 54" Rear Projection...

1 Answer

Replacing The IC's


Use a digital camera to take pictures of the chassis. Review the pictures to see if they can be used to reassemble the wiring plugs or restore the wire tie up positions. Remove the three screws that are located on the front edge of the chassis. After removing wires from their tie up positions or disconecting plugs the goal is to move the chassis into a position to expose the bottom side. Find a place to tie up the chassis using a piece of wire to one of the back screws to anchor this position. Use fresh solder wick and a 60Watt iron to remove the heat sink solder tabs switch to a 25 to 30 watt iron to remove the solder on the STK392-560 ic's. Remove the ic's from the heat sink and apply fresh heat sink grease before mounting the new ic's to the heat sink. Line the pins uniformly on the ic's if needed to install the ic/heat sink assembly. Use a flashlight or lamp to make it easier to see if the pins line up. Twist the solder tabs on the heat sink to secure it's position. Make shure all pins are present to solder in place on the bottom side.

Dec 05, 2006 | Sony KP-43HT20 43" Rear Projection...

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