PECHORIN'S home   account   archive   eshop   globalmediapro
.
.


Post new message


Home | Previous message

Re: Convergence problem with JVC AV-48WP74 tv

coldfriction Posted Oct 09, 2005, in response to:Kah

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.

Reply

Share |
12 comments, pages:   « 1 2

    Your posting is just what I need. I am having the same problem with the red convergence. I will buy the IC STK-150 and try to replace.This will be my first TV repair project, I have not used a solder rod in my life. Can you please help me to identfy the board where this IC chip is located and also the steps and precautions I need to take to remove the existing chip and replacing with 150. Pictures will be great help, but I hate to burden you. Thanks for your posting. Regards, Sri

    Comments 2, Last comment by Marcus Mar 05, 2007

    Excuse my ignorance but how do I get to the ic board that's inside. I'm going to assume that I remove the screws along either side? Thanks in advance

    Reply

Pages:   « 1 2



  


© 2001-2012 - Pechorin's - Contact Us - Report a bug

Pechorin's does not take responsibility for the content of the messages published in the Forum.

RSS feed