Opinion - Repair Mitsubishi back-projected

Archived from groups: alt.tv.tech.hdtv (More info?)

Hello,

Has anyone had fairly good success repairing a old Mitsubishi
back-projected TV? Mine is a model VS-412RS (15+ years old) and I'm
wondering if the necessary parts are still available.

The trouble is the color convergence worsen as the TV warms up. The
blue and yellow color look OK when the set is turned on, but as the TV
heats, the colors drift. Has anyone had this problem repair
successfully?

Thanks -

Archived from groups: alt.tv.tech.hdtv (More info?)

"Harlen Ng" <harlen@cadence.com> wrote in message
news:41B5D49A.CCA7BFA8@cadence.com...
> Hello,
>
> Has anyone had fairly good success repairing a old Mitsubishi
> back-projected TV? Mine is a model VS-412RS (15+ years old) and I'm
> wondering if the necessary parts are still available.
>
> The trouble is the color convergence worsen as the TV warms up. The
> blue and yellow color look OK when the set is turned on, but as the TV
> heats, the colors drift. Has anyone had this problem repair
> successfully?
>
> Thanks -

This is normally a very routine repair. Either bad solder connections or a
bad output IC, perhaps a related part or two. The Parts are easily
available. The question is whether the set is performing well enough to
invest the $200-400 in the repair, depending on the location and the
servicers available. If the tubes are in good condition, maybe it is
reasonable. Check with the local servicers and see what they charge.

I think the 412 is more like 20 years old, however, and would be surprised
if the tubes were not near the end of their useful life. The Mitsubishi
tubes seem to last longer than most, but 20 years is pushing it for any
RPTV.

Leonard.

Archived from groups: alt.tv.tech.hdtv (More info?)

"Art" <plotsligt@comcast.net> wrote in message
news:s8CdnZ5vlsBVCyrcRVn-rw@comcast.com...
> If I remember correctly these models also had problems with the yokes
going
> bad, maybe something to consider.

Art, I like top posting better, so take my comments in that context. This
group consists mostly of people who prefer bottom posting and I post that
way to accommodate the majority and to avoid the mess that was your last
post. At the very least you should consider trimming posts or posting the
way previous posters have to keep that kind of mess from occurring.

As for the Mitsubishi, yes, those sets did have some bad yokes but I never
saw one fail that caused drift. More likely bad solder, bad caps, or bad
outputs. Also, the servicer should be someone familiar with these sets. If
the static convergence is not centered, the DC of set can cause the outputs
to overheat, which causes drift. I have seen aging caps cause offset, which
makes the consumer adjust to correct it and as it gets the limit of the
static convergence controls the IC gets hot, causing it to fail. Always
best to have someone familiar with the failure modes to get to the bottom of
the problem.

Leonard