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.

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.

This is a VZ3 chassis....notorious for cracked solder connections on the
yoke plugs. Look at each yoke on the 3 CRT necks , you'll see a Molex plug
on each yoke. The top two connections are for the vertical winding. There
is a plastic tab that hinders easy soldering of these....carefully clip it
off with a good pair of dykes. You can then access the top 2 solder
connections.

Resolder these and also resolder the vertical output IC401.

This should take care of the problem.


--
==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)

========================

wrote in message
oups.com...
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.

No...the lightbox slides out of the cabinet and you can access the bottom
off the boards easily!

You need to remove the front screen and unplug the control panel harness and
speaker cable harness. Then remove the 2 panels between the lightbox &
cabinet sides.

Then there are 2 screws on the left and right bottom edge of the lightbox.

A couple more along the back plastic edge of the chassis and your good to
go.



--
==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)

========================

"MitsuProblems" wrote in message
oups.com...
Many thanks jeff and jumpster the your advice.

I cut off the plastic tabs behind the top two pins of the molex
connectors on the yokes and resoldered the pins on all three yoke pcbs.
The focus and alignment got a bit messed up but refocused using the
controls inside and aligned using on-screen display.

The tv worked for an hour or so, but was too soon for celebration.
Now the tv seems to work longer but loses the picture and the "good
old" lines come back when we change the channel or when the tv is first
turned on.

Looks like I have to resolder the vertical IC 401, also.
Being a novice at this, I need some help in locating the IC 401. Looks
like I have to take the low-voltage board off the cabinet and look for
it closely. Any advice?

THX,
MP