Removing STK-392-110 chip

https://www.youtube.com/watch?v=C9fiv4bI1qI
Replacing a DLP TV Chip - White Dots Issue - How to Fix...

1. Remove DMD Board Housing Screws. [02:34]
2. Remove DLP Chip Heatsink Screws. [03:31]
3. Remove DMD Board Screw. [03:58]
4. Reinstall DLP Chip Heatsink. [05:14]
5. Reinstall DMD Board Housing. [05:37]

https://www.youtube.com/watch?v=JgiZdc4kZDw

voltages to IC's There's a shielded module near convergence IC's It could be bad too. Check voltages to It.. I had simular problem /replaced IC's did not fix..Replaced module & did convergence.. TV was fine so try this 1st k

Most IC's on circuit boards these days are of the surface mount variety. You will need special Desoldering Equipment to remove these chips, especially the one wth 100 or more pins, the type of equipment used in this process heats all sides of the chip at once while a small suction that grabs the chip for removal. Now the SIP chips (Single inline package). chips which usually consists of less then 20pins can be removed with a desoldering gun such as the HAko 880 desoldering gun. Or you can use a standard soldering iron and solder Wick, that can be found at Radio Shack under Soldering Braide).. These procedures are common for all IC replacement. I am asuming you are trying to remove the Convergence IC on this model, The two large Black one labeled STK-392-110, the correct and easy way to remove these is to remove the entire board from the unit and remove the two screws holdinf each one in place, Unsolder the pins of each one and remove the IC, reverse this process to reinstall them. Good soldering technique is critical here as you don't want to bridge pins together causing yourself more problems. Double check your soldering and Double check it again.

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I learned today on my Mitsubishi VS-60621 (chassis VZ4) there are 3 convergence ICs (3, not just one as previously suggested), all 3 are STK391-020 located underneath the large heat sink on the upper right (as viewed from back of set), above the large PCB with the 6"x10" cover in the middle. The 3 chips are hanging upside down from their heat sink, have aluminum covers over them (so well hidden, it took me hours to find them, not knowing where to look), and the whole heat sink & chip assembly comes out by removing 2 screws, the front one must be accessed by removing the large lower front plastic cover and fiber-board piece behind it. Not necessary to remove the smaller plastic cover and control box above the big one. The big plastic cover has 2 large tabs on the bottom straddling the center post that will still hold it on once the screws are removed, gently pull down on them to release it. Not necessary to remove the glass doors, but probably safer to do so. Good luck!

Bad capacitors. They're cheap. Look for the ones closest to where the power cord comes in to the main pcb board. This will be your power supply circuit. Change them! They're probably dried out. If they're bubbled up, they're also bad. They're so cheap though, just replace them all.

When you replace them use the -180 version they will last longer.

It sounds as though you have a convergence problem. This problem is normally a convergence chip ( there are two (2) of them on the convergence board )
If you intend to correct the problem yourself, always remember to practice precautions by unplugging the tv before removing or servicing the set.
To change these chips, carefully follow these tips . I do suggest you change both chips as I have found that when one goes bad, the other one is on the way out also.

Remove the bottom back cover by using the proper screw driver or nut driver. usally a 1/4 inch nut driver or a phillips screw driver is all that's necessary.

When you have the boards exposed to view, notice on the left center of the convergence board ( the convergence board had 2 large ( large being 3X4 inches) chips next to each other. These chips normally are marked with number like STK 3020, STK 3050 etc.( I don't know the exact number on this perticlar set but they are all about the same ) They usally have about 15 pins ( wires ) coming from them. May be 12 or 18 but normally 15.
This board needs to be removed to change the chips, so remove any screws that mount the board and disconnect each wire connected to the board. ( NOTE : I normally mark each wire with some kind of a color code with permanite marker pen as to know exactly where to reconnect the wire to eliminate any mistakes )
With a soldering iron ( normally one of about 25-40 watts works well ) and some de-soldering wick ( can be purchased at most electronic parts stores or Radio Shack ), remove the chips.
Clean all the connections after taking the chips loose from the heat sink ( the heat sink is the aluminum plate the chip is screwed to ). Apply an ample amount of heat sink compound ( silicon grease it is sometimes called) ( can also be purchased at Electronic Parts Store or Radio Shack ) to the back of the heat sink and reinstall the new chips ( make sure the new chips are of exact numbers as the old), being extra careful not to bend the pins. Solder the pins being extra careful not to jump solder across any connections.( if you happen to apply too much solder and do in fact jump lead across the connections, simply use the de-soldering wick and remove any excess solder ).
Reinstall all the wires and screws to the board ( double check for mistakes ) and turn the set on, checking for the correct convergence. You'lle need to do a quick convergence with the magic focus switch after warming the set up for appr. 20 minutes. Reinstall the back of the set.
The set should work fine.
I do hope this helped
Ed
NC Electronic
Mills, Wyoming

Hi.

You will need desoldering braid or wick to remove the old solder from legs of chips, Ensure no solder is sticking any of the legs to the pcb.

Once done remove screws or clip holding chip to heat sink & remove the chip. If chip is stuck to heat grip it with pliers & work it loose then remove.

Remember to put new heat sink compound on the backs of the new chips when fitting.

My TV too got a "bow" at the bottom of the screen. Seem like many suggested replacing this STK chip and also it's $10/each so I went ahead buy 2 to replace the 2 in my TV.

Below is a pic of the inside of my projector TV with the STK-392-110 circled in green and as you can see it is easy to ID due to the HUGE heat sink that it mount on to help dissipate the heat. (sorry for the small size since Fixya limit the file size to 150KB)



I unplugged the TV for more then 3 days and that seem to discharged most of the components.

So here are the steps I take to do the fixing.
1) Before I even order the chip I open it up to verify the part number and it was STK-392-110. Did many research try to find as much as I could about this chip and make sure I order the correct one... so I made the order. While waiting for the product, the TV had been unplug ever since.

2) Well, in order to even get to the inside I need to dismount the back panel. So it had stayed open ever since, of cause out of reach of children.

3) The components arrived and I prepared:
- soldering iron
- solder
- heat sink compound (used mainly to fill in a good gap for CPU heatsink inside computer)
- and solder sucker (the sucker later I found to be useless).
- Flashlights
- Screw driver
- Plier.

O, and my brother offer his help which I found to be very useful. My 2 hands weren't enough to do this work.

4) Removed the 4 screws which I marked with the yellow arrow inside the pic.

5) I didn't want to remove any cable afraid that it might create other problems but had to remove about 3 cables to make it easier to lift and move the board around a little while fixing.

6) Removed 4 screws that mount the chip to it's heat sink using a very short screwdriver. Very little space to work with.

7) It was extremely hard to remove the old chip with the board still cabled to the TV. Many times I was tempted to disconnect all the cables. What prevent me from doing so was I couldn't think of a good way to document all the cables that I disconnect and there are just too many (IMO). I did take many pics just in case.
Anyway, what I did might not be the best way but it worked. I tip the chip back and forth to weaken the pins to a point that it broke. It took forever but it did work. After the chip broke off that I can desolder and remove each pin with the plier. Again with the little space to work with that made me want to remove it from the TV. The pins holes were still very messy and full of solder. My brother came up with a way to clean the hole using stripped wires. When the stranded strip wires touch the liquid solder, it help suck the solder out of the hole. I'm sure there are better ways to clean the holes.

8) We had a little hard time putting the new chip in b/c a few pins bended a little and not align with the holes on board. And when added the compound to the chip, it made it even harder since now the chip need to stay away from the heat sink or else it'll stick to the heatsink. Finally we got the new chip in the holes on the PCB with the compound and all, so it just a matter of screwing the chip onto this heat sink.
9) Turn on TV and pic is 99% perfect again. Why not 100% U might ask.. b/c I saw a tiny out of align colors on the left of the screen. Not very noticeable but I can see it when I pay close attention.

Cost for the two chips were $20 included shipping. Hey, it's a lot cheaper then buy new TV and only 2 chips trashed instead of the entire TV. Anyway, I think I knew which chip went bad. Because one chip had hardly any of the compound. This compound help the transfer of heat to the heat sink.

Hope this help someone.

if you can remove the rear panel assy. look for the convergence ic's they start with stk--- and you got the part number you need a source panasonic is 814 source and the number on the ic's stk 390 ----/