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Icaillo I have read most your posts for the Mitsu convergence problems and have determined I likely have a condition with mine that more than likely is a cracked pin as it is intermittent and can be corrected with a light jar to the chassis. I will put in the new IC's and check over the board, resistors and anything else that looks suspicious. I've included a couple pics to see if you concur. As an automotive tech for many years this shouldn't be too tough as long as the eyes hold out . Thank you for all the time you put in.

http://s361.photobucket.com/albums/o...current=tv.jpg

http://s361.photobucket.com/albums/o...urrent=tv2.jpg

After repairs I will follow up with any challenges I find for a home repair with a few pics. From the information sourced in many threads on this forum this is a common home self repair. For those wondering I have good technical skills but do not have much in the way of electronics circuit board repair. I have the IC's ordered through ACME and will be out of town for next weekend so expect it in another 10 days or so.

Mike
 
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Hello Icaillo,

I have the board out and IC's removed. I did find a circle crack in one solder joint on the end pin on one of the chips. With a magnifying glass you could see it as well as a slight movement of the pin. I'm taking pics to document and had a couple of notes for everyone and questions that occured to this point. Prior to removing the chassis from the set I read a passage stating to discharge the high voltage leads to the chassis ground. Rather than doing this I was just carefull to avoid contacting them but was curious. My experience with high voltage and electronics requires some caution and where in the set would be a safe location to do so and is it really neccesary? To clarify does it stay at a high voltage level indefinately or drain off over a period of time?

For this IC I wanted to try the bulb method to remove the solder as well as the wicking ribbon. I found the ribbon with flux absorbed the solder quickly and cleanly and was much quicker than with the bulb. With the IC's out is there generally any necessity to cleaning that area of the board with a light alchohol to insure all residual material has been wiped away or is it not that sensitive. Most circuits I've worked on are not so close together and I was right my eyesight so far has been the biggest challenge. Nothing a set of 2X glasses and lighted magnifying glass couldn't handle.

Thanks,
Mike
 

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These tubes are relatively small and do not hold a charge like larger CRTs. The bigger danger is that the capacitors in the power supplies may remain charged, but if the set has been off for a few days it likely discharges pretty completely. Best to check the power supply lines and larger caps with a meter to know for sure.

I use a fiberglass brush for cleaning the board of old flux, both before installing the new chips and after. Clean work makes for faster soldering and less heat to damage a board, less likelihood of solder bridges or damaged traces, and a clean finish lets me check my work.
 
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Discussion Starter #4 (Edited)
:yay2: :flex:

We have a winner! wanted to wait a couple days after completion to make sure all was well. I did have a fiberglass brush and cleaned the board prior to installing the chips. After applying the grease and working the heatsink and chips to insure good contact I installed the chips into the board, attatched the heat sink to the board using a couple of the plastic wall anchors used for hanging pictures and screws through the boards to hold in place. I then attatched the bracket securing the heat sink to the chips and tightened everything down then soldered the chips to the board. Reassembled the board to the chassis after blowing all the dust off outside and installed to the TV. Powered it all up and with a sigh of relief it works perfectly. Reset the convergence settings and so far so good. Now I need to learn about fine tuning this set and possible tweaks I need to look into.

Thanks Again
Mike

Just a note to supporting scouting. My former years working with the Boy Scouts was some of the most rewarding years I can remember. For a number of years was involved with Pack / Troop 398 out of Lodi and served as District Training chairman for a couple years.
 
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