Question about Samsung PCN5425R 54" Rear Projection Television

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Blue alignment still does not work after IC replcaement

I replaced two STK392-040 ICs but the problem is almost the same as before. Before replacement Bule color was looking as rainbow but now it is shifted to right about an inch. With Mute-1-8-3 on remote I can adjust RED in H and V, Green in V direection ONLY but can not adjust Green in H and Blue in both direction. Please let me know what parts I have replace to fix this. Thanks, JOK

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Re: Blue alignment still does not work after IC...

You are going to need to get a schematic diagram and trace out the resistors and capacitors in the convergence circuit or power supply as most of the time you dont need one and replaceing the IC's will fix it, but sometimes other things have went bad because of the defect in the Convergence drive IC's or one of the new ICs could be defective. Would not be the first time I have seen this problem. Did you buy tHe exact replacement IC? Did you use heat sink compond behind the IC on the heat sink? These two things are very important as well. If you dont have a multimeter and now how to us one as well as read a schematic, you may want to seek out the assistance of a pro. Good Luck PS please dont forget to rate this thread.

Posted on Oct 22, 2006

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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...


Convergence - diagnosing a convergence problem - bowed picture/rainbow...

Convergence = the joining together of the 3 colors making up the picture cd3c9b5.jpg
Here is a picture of a Convergence mis-alignment

Typical repair:
Replace both convergence ICs + any burnt up resistors + any blown fuses = repair cost $250-350 or repair it yourself for about $30 and a few hours of time. Repairing requires tools, soldering and disassembly skills.

All CRT rear projections have 3 picture tubes - red, green, and blue.
Each picture tube has an electromagnet (yoke) that pulls the beams horizontally or vertically. Therefore, there are 6 convergence amplifiers. One for each color, vertical and horizontal. Any one of these amps can fail independently, or whole sections can fail. Depending on the design of the TV, almost all use an IC (integrated circuit or "chip"). These have a part number beginning with STK (ie stk392-110 most common *see pic below) and run very hot, and fail regularly (5-8 years). Most STK designs have 3 amps per IC, giving you 2 ICs to run the convergence. Many manufacturers will have all 3 vertical amps on one, horizontal on the other. Others will have both the red amps on one, the blue on the other, and the green will be split between the two ICs.

The best way to diagnose is to enter the convergence alignment for your TV. Some TV's will have an auto alignment, others will let you adjust the colors yourself. The auto align is hard to troubleshoot because you cannot tell which will not move. If auto align does not work, you have some sort of failure or malfunction. In a manual alignment, you can see which colors will move and in which directions (vertical or horizontal). Using this deduction, you can see which amps have failed and replace accordingly. Red and Blue are typically adjustable, while green is left to factory alignment and not user adjustable. Try looking at the picture with something familiar on the screen. Try to have words or letters around the edges. You can usually see which colors are straight and where they belong, and which colors are out of place. If every color is off in both directions, this is a good indication that there is no power at all. The amps run off + and - 24 volts, and usually have 2 fuses for each power supply line. If everything is off, these fuses probably blew when one or both of the ICs shorted out. *RCA customers see below* Each convergence amp has some resistors that set up the amplifiers gain. Typically and input resistor (small like 1.5 ohm 1 watt) and a feedback resistor (larger like 150 ohm). Its quite common for the smaller value input resistors to blow out, so check them before you replace everything. They are typically right by the ICs (largest heatsinks in the tv) and most of them you can see if they're burnt up. Unhook the yokes (mark them if unmarked) and then you can OHM out the resistors to see if they are opened up. Replace any possibly bad resistors, sometimes they check good but look damaged = replace them! Some TVs will just be dead or go into shutdown. If the + or - 24volt fuses are blown, suspect the ICs and replace them both.

This is kind of tricky, as these ICs usually have 18 pins on each of them. Find all your bad parts, remove them and replace with good ones. The fuses and resistors are pretty straight forward. The ICs are harder. They are mounted to the heatsinks and depending on the make and model, they can be hard to get out. They are thermally bonded to the heatsink with heat sink compound or paste. If it is dry, replace the paste with new stuff. Make sure to get a nice, even, and thin layer on there to give a good heat transfer. The trick to the ICs is to make sure all your pins are straight before you install them. Start at one end and slowly work the IC and get each pin to pop into the hole. Once you solder in all the bad parts, the TV should be able to kick back on and run. At this point, its good to center the colors up in the customer mode. If you want to take it further, get the service manual for that TV and go into service mode and do the full re-alignment. This can backfire so get the manual or make sure you know what your doing as you might accidentally erase all the data.

*stk392-110 = the most common IC. Almost all look just like this

Convergence is a very common failure and can be repaired by someone with a little soldering know how and some time to dedicate. Its quite complex, and every make and model are different. Let me know if you have any specific questions for your product and I can help you get the job done. Remember to have patience, good luck!

*RCA typically uses no ICs, and the convergence power board blows out (older models - wood cabinet) OR a small fuse blows out because of solder connections on the flyback transformer (newer models - plastic cabinet) and just needs resoldering and a new fuse.

on Jun 01, 2010 | Projection Televisions

1 Answer

Convergence function reads error

Check the 1.8 ohm resistors in the convergence circuit there will be 6 all 1.8ohms, They will be where your STK ICs are
STK392-110s which are Big Black ICs,You may need to replace ICs They are Big Black ICs with STK392-110 printed on them Mats has them 1-800-628-1118

May 30, 2010 | Toshiba 51H83 51" 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.


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

1 Answer

Rca rear projection screen way to much blue

replace convergence ics .press the menu and go into the convergence
alignment.see if you are able to align the blue convergence. if not replace the convergence ics.

Aug 04, 2009 | RCA P52771AT 52" Rear Projection...

1 Answer

Mdl kp53v85 red is out of alignment and bowed

Your convergence ICs are bad. They are about 20 pin chips located on the D board. They are on the largest heatsinks on the board. Check the resistors and fuses underneath or next to the heatsinks with an ohm meter to make sure all are good as they can fail with the ICs. This is a difficult repair but can be handled by a moderately skilled electronics tech. After all bad parts are replaced, run the magic focus to hopefully re-align the colors. If you have to go into service mode to re-align convergence data, the complexity of the repair just went up another notch. On a sony, service mode is tricky and a service manual would be highly recommended. Your tv uses two stk392-150 ICs (ic 1502 and ic 1505)

Dec 07, 2008 | Sony Projection Televisions

1 Answer

Red, green and blue are out of alignment

Just click below for convergence repair kit;

Blue wave coming up frpm the bottom of the screen on the lower left symptom is for busted convergence IC,you must replaced this IC in order that will works better again.STK 392-xxx ICs and it's associated resistor,this resistor automatically change value,can caused truoble even though you change the ICs.If you bring this to a service center they cost you $600 to $700,but if you buy the repair kit you can save more,don't wory it is very easy because there is intallation guide including in the repair kit. Feel free to ask whatever the result... click the link for sample picture guide step by step installation;

Hope this may help;


Sep 08, 2008 | Toshiba TZ50V51 50" Rear Projection...

1 Answer

Blue color cannot be adjusted

there are two ics trhat control the three colors alignments. Its always recomended to replace both Convergence ICs at the same time when doing the repair as they both share the green color between the two ICs.

Sep 03, 2008 | Mitsubishi WS48511 48" Rear Projection...

1 Answer

Red Offset Image

yes the convergence ICs need to be replaced they are both STK392-120 ICs and you will also need four 6.8 ohm 1 watt resistors you can get replacment ICs and resistors at the following link and they provide free instalation instructions with pictures and free on line instant messageing to help you do the repair yourself. Heres the link.

Aug 14, 2008 | Philips 55PW9363 55" Rear Projection...

1 Answer

Phillips 60pw9363 Which IC is red and which is blue

Thats the DPTV 335 series chassis when the IC blows it will usually take out 1 or 2 6.8 ohm resistors along with it. Look at the resistors right next to the ICs you will notice 1 or 2 with a little discoloration in the middle replace those and your set should be back to working just fine. Let me know if you need more help. These resistors are easy to spoy they all look alike and shouldnt have any bands on them they will be stamped 6R8 ohm 1W J

Apr 12, 2008 | Projection Televisions

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