I work in a salvage business wher i get to see alot of brand new
electronics . This means LCD tv sets .
I noticed in some of these they cover each circuit board with metal
covers . Lately i have been seeing overkill on these covers . This makes
the boards fully covered even the edges and only several very tiny vent
holes in the top , so small you cant see in at all

Now i see most sets only cover a couple boards but they have very big
holes . The rest of the boards are fully open .

This last set was so ``cover overkill`` it would overheat . I removed 3
covers and it works fine .
The power supply is a separate box on the power cord . This supply is
cased in a solid plastic box , take that off to find 2 layers of
aluminum wrapped around it all taped on with yellow tape .
Take that off and find a full layer of plastic and more yellow tape ,
take that off to find a full 4 sided thick aluminum heat sink all
screwed together , at least the ends are open .
Take the top off of that and all the small transformers are tightly
wraped in more of that yellow tape . Any open spots in that heat sink
had pieces of clear stiff plastic tucked in next to it ... then to top
that off they squirted white silicone glue here & there down between
parts .

I can see a bit of protection from dust and some RFI noise elimination
protection but this particular product was clearly made for planned self
death in a short time .

I see plenty of electronics of the same nature with only 1/4 or less of
this ``smothering`` and they work just fine .

I think it's more of a tradeoff between RFI protection and repair cost.
The cheaper the parts are, the harder it is to keep the FCC off their
backs, but if they use -really- cheap parts and put tons of shielding
on them, they can handle the occasional warranty claim. And of course
whatever happens after the warranty expires is not their problem.

My guess as to why this happens is that LCD sets are one very expensive
component wrapped with just enough support electronics to make a
product. If you could make a TV with an LCD panel and one dollar worth
of extra hardware, you would have the holy grail of consumer
electronics.

Or maybe the TV manufacturers have a soft spot for salvage guys like
yourself.

"they work just fine" is a very subjective term in my experience.

Manufacturers don't like to spend extra money on components or
engineering. The shields are there for a reason. Remove them
and the different sections of the circuits can interfere with
each other. They can cause problems with other equipment nearby.

*You* may not think its noticeable, or be affected by it when you
plug one device in to check it out on your bench. But it's not there
to shorten the lifetime of the device.

Ken G. wrote:

I see plenty of electronics of the same nature with only 1/4 or less of
this ``smothering`` and they work just fine .

The supplies for the lamps, otherwise known as ballast supplies, are
extremely noisy, producing a lot of RFI. The shielding is to stop it's
intrusion into the other circuits of the set, inclusive of the signal
processing and switching circuits. Removal of the shields may introduce
unwanted distortion nor only into the video, but probably also into the
colour processing and audio circuits.
"Mike Berger" wrote in message
...
"they work just fine" is a very subjective term in my experience.

Manufacturers don't like to spend extra money on components or
engineering. The shields are there for a reason. Remove them
and the different sections of the circuits can interfere with
each other. They can cause problems with other equipment nearby.

*You* may not think its noticeable, or be affected by it when you
plug one device in to check it out on your bench. But it's not there
to shorten the lifetime of the device.

Ken G. wrote:

I see plenty of electronics of the same nature with only 1/4 or less of
this ``smothering`` and they work just fine .

I understand the need for shielding . The subject set here is overkill
and i believe made to self destruct fast . 2 of these now that wont work
with the shields .. or lets say COVERS in this case . After they get hot
they do kooky things .
With 3 covers removed they work fine . No picture noise and it does not
disturb things next to it .
You would have to see this one to believe it i guess .