DIYbanter - View Single Post - Mitsubishi VS-5043

wrote:

Hi Folks,

I have a mitsubishi Vs-5043 bought around 1997. Couple of months ago,
it started having raster problems. Picture disappears, three curved
red, green, blue lines appear in the middle of the screen. If I turn
off the TV and turn it on after a few minutes, the picture comes back
for around 5-10 minutes but, it disappears and the curved lines appear
again.

I opened up the front and back covers and looked for any obvious
problems but could not find anything glaring (like leaking coolants,
burnt components).

As this seemed to be caused by a over-heated component, I put a fan in
front of the TV and it ran fine for more than a hour and half and did
not lose the picture.

Any suggestions/wisdom? ( for finding the offending component(s) and
not plan-b: fixing a nice fan on the back of the TV!)

M. P.

If the lines are horizontal - left to right - then it sounds like you
have two problems. First you are losing vertical deflection, causing
only a horizontal line.
Second the fact that the three colors are separating and curving sounds
like a convergence problem.
Convergence is what lines up and aims the three picture tubes' pictures
to generat one image with the right colors in the correct places.
If it all happens at one time - that is the picture is normal then goes
straight to missing vertical AND separated/curved colored lines - then
it sounds like you are losing a power supply voltage which supplies both
the vertical and the convergence circuits at the same time.

These TVs are notorious for bad capacitors at that age. Even if only
one or two may be causing the problem, the whole set may need to be
re-capped - replacing every electrolytic capacitor that has gone bad,
may go bad, or is likely to go bad in the future. There may be a few
hundred parts to change.
The parts are inexpensive but the amount of labor involved may make the
TV not economical to repair.
A TV of this age usually doesn't have much life left in the picture
tubes - making a repair of this type worthless.