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Convergence problem with JVC AV-48WP74 tvKah Posted Sep 23, 2005
Convergence problem with JVC AV-48WP74 tv
Hi, my tv is less than 2 years old, the RGB lines won't converge. I tried all different ways per the manual and internet sites to adjust the convergence (automatically and manually) but the lines will not converge. I suspect certain components have failed. Let me know what parts i have to replace.
16 comments, pages: 1 2 »Pages: 1 2 »
I am not sure if this is a convergence issu or not. I see a big green line that goes across the top half of my TV. Has anyone seen this issue.??
cannot converge auto or manually. Red and blue lines all over and out of focus.
I have the same problem with my tv. Except for last week it just quit all together and now the power button just flashes off and on. No picture what so ever. I called a repair man on Monday, was suppose to be here Today @ 3pm and he didn't show up til 7pm and after charging me $72.00 to come out he told me it would cost me $578.00 to fix the tv. I need help please I don't want to throw it out, but I cannot pay this amount.
This might help. I had a problem similar to yours. Basically the red went out of alignment. It is pinched or bowed at the top of the screen and will not converge with the other colors. This website was also helpful to learn about the problem and what worked for other people. http://www.network54.com/Forum/185128 http://archive.avsforum.com/avs-vb/history/forum/63-65.html I found that the problem is very common with projection TV's and the STK are the problem chips. A guy from the web helped me out with the problem and here is his response. =-=- =- =-= -= -= - chances are that IC804 has failed. You have two ICs that allow you to converge the three colors. IC804 is used for Red Horizontal and Vertical Convergence and also for Green Vertical Convergence. IC805 is used for Blue Horizontal and Vertical Convergence and also for Green Horizontal Convergence. These ICs run very hot and have a very high failure rate which sometimes will cause damage to resistors in their associated circuits. They are both STK-110 and it's best to replace them both at the same time. It's also a good idea to upgrade them to either STK-150 or STK-180. These will run a lot cooler than the STK-110. =- =- =- =- =- =- =-= -= - Before replacement do inspect for any open or overheated resistors as I stated earlier. Being you only have problems with Red Convergence the plus and minus power supplies should be okay since they are common to both ICs. Try www.tritronicsinc.com. They have the Hitachi CZ00433 (STK392-150) in stock for $20.11 ($32.43 retail). These are Hitachi OEMs. I've had very good results replacing STK392-110s with these chips. Do check for open or overheated resistors before replacing these chips. Good Luck, Eric =- =- = -= -= -= -= - =- =- =- =- =- =- =- I replaced the STK392-110 with STK392-150 and it worked. Basically here's how I did it. First, I removed the board which the STK chips are attached to. The board which the STK chips are attached to are at the very inside of the TV. You will see two black heat sinks where the ships are located. There are 3 tabs/clips to push and to be able to remove the board. Mark the cable that you will remove out of the board so you know how to put them back. I just scribe color code to the plastics. To remove the solder, use a wick and a 45watt soldering iron. Place the wick on top of the solder and heat it up with the soldering iron. The solder will be absorbed by the wick. It's a clean process. Install the NEW chip on the board. Screw the chip then solder the terminals. T The process took 15mins.
Outstanding ! In plain simple english too.Beats knowing whats going on in the back of the t.v. & the back room of your favorite t.v. repair shop. Knowledge is everything !!! THANK YOU
I am having the same problems with my JVC AV-48WP74 tv. I can not believe that so many people are having the same problem with no recall. I have had my tv 4 years and I think I have had this problem for at least three years. I can't fix my tv so I guess I will have to take it to the tv repair shop. Does anyone know how much this repair cost?
sounds to me like u need to change the ic's, they would most likely be the STK392-150 $10-15 part. located on the convergence board big & black. good luck, just some soldering.
I fixed my TV for a total cost of $34.50 using the advice presented. Look for the burned 2.2K resistor and change it and its associated STK392-110. Make sure that you change the resistor or the IC will probably burn out again. Check all diodes an resistors in the circuit just to be sure. Also, I didn't have a schematic diagram but took a guess that the resistor is what's causing the problem. I believe that it overheats and its value drops until the IC current is exceeded and it fails. I modified the design slightly in an attempt to prevent future failures. Instead of using one 2.2K resistor, I used four (two in series, in parallel with two in series). In this way, the current (and heat) is split in two but the resistance remains 2.2K. Time will tell if this fixes the design. The repair bill would have been $316 so it was worth doing it myself. My TV works great. Thank you for all your help. Mark
I think we all have had or will have the same issue with this (or any other "Big Screen" television). I have the exact same tv as you and had this issue and I let the problem sit for about a year, and after attempting to sell it as is and a guy trying to rip me off by offerring me $100 for it, I refused and started my search for a repair person. Luckily I found a repairman that actually comes to your home and will take a look at it and give you an estimate of what it will cost - FOR FREE! He came over just this past weekend and fixed the problem...as everyone else is having, it was the IC Converters that went bad. I asked him if this is normal and he said yes, they will eventually go out because the manufacturing company only installs the basic chips on TV's, so it's not a defect of any sort. He replaced them both on the spot and about an hour and $200 bucks later, my TV was back up and running. He guaranteed his work and I watched him install them (I have a fear of people saying they did one thing and doing another, but charging you your 1st born to pay for it). My suggestion to you would be to go ahead and see if you can find someone in your area that will come to your home and repair it - it's been 3 years and I'm sure you walk in the room and just "wish" it would work one day...so do yourself a favor and spend the couple of hundred dollars if you have it...if you're like me, you already invested about $1800 in the tv and all other types of things for it (dvd player/vcr, gaming consoles, etc.)
just like lophyte who posted earlier i to overheated my contacts, and although the picture is there so is the blue lines of the convergence being off. if you intend to do this repair i would strongly suggest that you do what eric said in his posting earlier about the wicking process. that way you will not have the same overheating problem. now i am trying to decide whether to replace the board or not. did anyone else have trouble with the first long plug on the board going from right to left?