Mitsubishi WT-46807 - blue shadowing

[DFW Guy]

We had this TV fixed last June - new power supply. In the last two months, it's started doing this (see pic).


If you can't get this image or want a bigger pic, there is a link here:
http://members.aol.com/b1bbet/tvbad.jpg

You can see the slight blue shadowing and mild bending, too.

It will go away if you turn off the TV then turn it on again. On occasion, it may take 5 or so "flips" to get it to go away but after it's gone, it's okay for the duration. It does come back after cool down.

Ideas?

Oh, in my LTG, I've seen some posts for similar problems about reflowing the solder on the ICs. Don't know if that would help here but I could do that, I just have to know which ICs and where they are.

Thanx. :)

[57U]

Convergence ICs are likely shot. Also replace any associated resistors and check the convergence board for cracked solder. See the following post and any similar ones in the Mits forum:

http://www.hdtvoice.com/voice/showthread.php?t=28929

[DFW Guy]

Thank you very much for the links. Would not an intermittent problem like this mean it's cold joints somewhere rather than a bad part? I service classic arcade games and typically a "sometime problem" means a cracked joint or something similar. . .

[DFW Guy]

Well, the shadowing problem seems to have been corrected by the resoldering. However, now I have no sound.

Virtually certain I hooked up all the connections I had taken off. Just now no sound on any output channel.

Any pointers from here?

:sightv:

UPDATE: Oops! Missed one connection. All good now! Leaving this here as a reminder for everyone to TRIPLE CHECK all your connections! :pimpy:

Thank you again for your help! :thankyou3

[57U]

a "sometime problem" means a cracked joint or something similar. . .
As mentioned in my link, cracked solder is one of the possible causes of the issue, however, when you have the board out, it's often recommended to replace the ICs and resistors since it's only a little more work and a little more money, instead of having to do the job twice...

[DFW Guy]

Well, turns out it's not fixed. Much better - typically only 1 turn off/on now but still not perfect.