WS-55805 55" screen that I've had since 2000. Always worked just fine until today! No picture, just sound.

Hi Sharon,

I have the same exact TV and the same exact problem....except today the screen went black and I no longer get a picture from any source. I've had the TV for exactly 13 months. IF you've had your TV for less time, I'd return it.

A common failure for those symptoms are IC9C25 a BA09FP which is a low saturation 3-pin regulator, Mitsubishi p/n# 270p677030.
Depending on it's failure it can cause slick raster, blue screen or what we refer to in the industry as a venetial blind effect. This is not the kind of repair you want to tackle yourself unless you're pretty competent in electronics and have some fair amount of test equipment. Reason is, although this may ultimately be the only piece of the puzzle it also may not and several diodes in that circuit could also be the cause. You would need to check for any leaks along that circuit and/or intermittent shorts that may have contributed to the failure of that IC..
Short version is take it in and have it looked at professionally. It's worth the expense and you'll save yourself a lot of headache if something more is wrong.
Bill

I know these sets pretty well--worked on a lot of them when new and later--one of two possible ideas=

1. Either a odd convergence problem==confirmed or denied by going into the convergence menu (in customer menu) and selecting advanced which will bring up a grid of lines--if see the same issue (I will attach a photo of a Mitsubishi with this problem) it can be fixed.

2. Some sort of issue with the circuit board on the end of the Blue tube(you are missing blue=black) but usually in this set if that happens it is uniform and on both sides of the screen, not the top.

Let me know what you find.


I doubt it is convergence, but does not hurt to look--if the missing area was perfectly rectangular I would suspect up/down centering adjustment.

There is one other possible thing to try--we will leave it for last--set has 3 hidden menus and one is OPTION menu which allows a hard reset of entire set--sets everything back to factory except convergence adjustments which are stored in another area.

The main board has an issue which has most likely blown a fuse. Those boards have been discontinued so repairing that one will be at least a couple hundred depending on the shop doing it.Or yo umay be ble to locate a used one on ebay .

Yes the problem can be came from broken main board, replacement usually available.

Journeygal,
Check The Following Components Off Ihvt pin 3 For Open: R558 P/N 103p338010, D 553 264p338010, L502 321c030010, R521 1.2 Ohm You'll Need A DMM For The Job And Any Cheap One From Radio Shack Will Work.
Bill

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My tv was working fine until now 8-9-08, it would not come on. The timer light comes on and goes off immediately.

Sounds like the CRTs are going into protective blanking due to the vertical output ic needing to be resolderd. Try resoldering the vertical IC that may possibly fix the issue.

push qv and 9 on your remote and a screen will come up and follow the directions to correct your problem.

sounds like convergance ic's mits is also know for bad caps
1000uf @ 16v check for bulges on top of the cap
http://cmpalmer.blogspot.com/2006/11/fixing-my-own-tv-part-ii.html