JVC 55" Rear-projection TV

Tom Del Rosso wrote:
Michael A. Terrell wrote:
Jim Thompson wrote:

Note that there are only two CRT's shown... the third was the
failure mechanism... leaking oil ;-)


Glycol based coolant. That was a common failure, and fairly easy to
fix.

Too late now. :)
Click to expand...

Some people never do any P.M. ;-)


--
You can't have a sense of humor, if you have no sense.
 
Michael A. Terrell wrote:
Tom Del Rosso wrote:

Michael A. Terrell wrote:
Jim Thompson wrote:

Note that there are only two CRT's shown... the third was the
failure mechanism... leaking oil ;-)


Glycol based coolant. That was a common failure, and fairly
easy to fix.

Too late now. :)


Some people never do any P.M. ;-)
Click to expand...
Preventive maintenance on a picture tube?

I tried fixing a TV from the 90's once. I'm sure I could have done it, if
it had been the least bit designed for mantenance. The damned back and
bottom were molded together, so if you took off the back then it had no
bottom (or support for the board, which was left dangling) and it kept
threatening to fall back and crack the neck off. I decided it wasn't worth
the bother or danger.


--

Reply in group, but if emailing add one more
zero, and remove the last word.
 
On Wed, 9 May 2012 01:26:15 -0400, T <kd1s.nospam@cox.nospam.net>
wrote:

In article <24ljq79aah8j1795d9bddkg4q28qo2qs0m@4ax.com>,
flipper@fish.net says...

On Tue, 08 May 2012 17:06:30 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Mon, 07 May 2012 23:57:09 -0400, ehsjr <ehsjr@nospamverizon.net> wrote:

Jim Thompson wrote:
Here it is, broken open, a couple of hidden screws "assisted" by force ;-)

http://www.analog-innovations.com/SED/Gutted_JVC.jpg

Anything there worth saving?

I see some nice heatsinks.

The "screen" _is_ a grating (Fresnel?). Is that worth anything?

...Jim Thompson

Hook up wire from the harness. :)
Ed

Full knock-down...

http://www.analog-innovations.com/SED/JVC_TV_KnockDown.pdf

They don't make them like that anymore.

...Jim Thompson

Good grief, you think there's enough timmers in there?

I counted - I saw 115 trimpots on that one board. Damnation!

However, it is a scavengers dream. Lots of well marked VLSI chips on
there.
Click to expand...

I was thinking the same thing, right after I recovered from imagining
what it took to align that beast.
 
Tom Del Rosso wrote:
Michael A. Terrell wrote:
Tom Del Rosso wrote:

Michael A. Terrell wrote:
Jim Thompson wrote:

Note that there are only two CRT's shown... the third was the
failure mechanism... leaking oil ;-)


Glycol based coolant. That was a common failure, and fairly
easy to fix.

Too late now. :)


Some people never do any P.M. ;-)

Preventive maintenance on a picture tube?
Click to expand...

On tube type TVs. I did that for about nine months, in the US Army.
They were used as video monitors/TVs in classrooms & Air Traffic Control
Towers. where you wanted them to work to their design. Since those
projection CRTS are know to leak after so many years, what is wrong with
replacing them before they fail and damage the circuit boards?


I tried fixing a TV from the 90's once. I'm sure I could have done it, if
it had been the least bit designed for mantenance. The damned back and
bottom were molded together, so if you took off the back then it had no
bottom (or support for the board, which was left dangling) and it kept
threatening to fall back and crack the neck off. I decided it wasn't worth
the bother or danger.
Click to expand...

It isn't that difficult, if you really want to fix one. That problem
didn't start in the '90s, and was done on computer monitors as well.


--
You can't have a sense of humor, if you have no sense.
 
On Thu, 10 May 2012 01:33:44 -0400, "Tom Del Rosso"
<td_03@verizon.net.invalid> wrote:

Michael A. Terrell wrote:
Tom Del Rosso wrote:

Michael A. Terrell wrote:
Jim Thompson wrote:

Note that there are only two CRT's shown... the third was the
failure mechanism... leaking oil ;-)


Glycol based coolant. That was a common failure, and fairly
easy to fix.

Too late now. :)


Some people never do any P.M. ;-)

Preventive maintenance on a picture tube?

I tried fixing a TV from the 90's once. I'm sure I could have done it, if
it had been the least bit designed for mantenance. The damned back and
bottom were molded together, so if you took off the back then it had no
bottom (or support for the board, which was left dangling) and it kept
threatening to fall back and crack the neck off. I decided it wasn't worth
the bother or danger.
Click to expand...
Same here. The only easy access was to that alignment board (with those ~100
pots :) and the backside of the CRT's... the rest was accessible only by
disassembly of the particle-board-bonded-vinyl case.

...Jim Thompson
--

| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
On 5/10/2012 11:07 AM, Jim Thompson wrote:
On Thu, 10 May 2012 01:33:44 -0400, "Tom Del Rosso"
td_03@verizon.net.invalid> wrote:


Michael A. Terrell wrote:
Tom Del Rosso wrote:

Michael A. Terrell wrote:
Jim Thompson wrote:

Note that there are only two CRT's shown... the third was the
failure mechanism... leaking oil ;-)


Glycol based coolant. That was a common failure, and fairly
easy to fix.

Too late now. :)


Some people never do any P.M. ;-)

Preventive maintenance on a picture tube?

I tried fixing a TV from the 90's once. I'm sure I could have done it, if
it had been the least bit designed for mantenance. The damned back and
bottom were molded together, so if you took off the back then it had no
bottom (or support for the board, which was left dangling) and it kept
threatening to fall back and crack the neck off. I decided it wasn't worth
the bother or danger.

Same here. The only easy access was to that alignment board (with those ~100
pots :) and the backside of the CRT's... the rest was accessible only by
disassembly of the particle-board-bonded-vinyl case.

...Jim Thompson
Click to expand...
Have you melted any coins or started a fire yet with the Fresnell lens?
Wear two pairs of sun glasses or some cutting goggles,
the hot spot is extremely bright.
Mikek
 
On Thu, 10 May 2012 13:26:49 -0500, amdx <amdx@knologynotthis.net> wrote:

On 5/10/2012 11:07 AM, Jim Thompson wrote:
On Thu, 10 May 2012 01:33:44 -0400, "Tom Del Rosso"
td_03@verizon.net.invalid> wrote:


Michael A. Terrell wrote:
Tom Del Rosso wrote:

Michael A. Terrell wrote:
Jim Thompson wrote:

Note that there are only two CRT's shown... the third was the
failure mechanism... leaking oil ;-)


Glycol based coolant. That was a common failure, and fairly
easy to fix.

Too late now. :)


Some people never do any P.M. ;-)

Preventive maintenance on a picture tube?

I tried fixing a TV from the 90's once. I'm sure I could have done it, if
it had been the least bit designed for mantenance. The damned back and
bottom were molded together, so if you took off the back then it had no
bottom (or support for the board, which was left dangling) and it kept
threatening to fall back and crack the neck off. I decided it wasn't worth
the bother or danger.

Same here. The only easy access was to that alignment board (with those ~100
pots :) and the backside of the CRT's... the rest was accessible only by
disassembly of the particle-board-bonded-vinyl case.

...Jim Thompson

Have you melted any coins or started a fire yet with the Fresnell lens?
Wear two pairs of sun glasses or some cutting goggles,
the hot spot is extremely bright.
Mikek
Click to expand...
I haven't tried it yet. But it's not circular... JVC calls it "lenticular".

http://en.wikipedia.org/wiki/Lenticular_lens

It's what I would call a "grating". So I'd guess it would focus a line rather
than a spot.

...Jim Thompson
--

| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
On 5/10/2012 1:39 PM, Jim Thompson wrote:
On Thu, 10 May 2012 13:26:49 -0500, amdx<amdx@knologynotthis.net> wrote:

On 5/10/2012 11:07 AM, Jim Thompson wrote:
On Thu, 10 May 2012 01:33:44 -0400, "Tom Del Rosso"
td_03@verizon.net.invalid> wrote:


Michael A. Terrell wrote:
Tom Del Rosso wrote:

Michael A. Terrell wrote:
Jim Thompson wrote:

Note that there are only two CRT's shown... the third was the
failure mechanism... leaking oil ;-)


Glycol based coolant. That was a common failure, and fairly
easy to fix.

Too late now. :)


Some people never do any P.M. ;-)

Preventive maintenance on a picture tube?

I tried fixing a TV from the 90's once. I'm sure I could have done it, if
it had been the least bit designed for mantenance. The damned back and
bottom were molded together, so if you took off the back then it had no
bottom (or support for the board, which was left dangling) and it kept
threatening to fall back and crack the neck off. I decided it wasn't worth
the bother or danger.

Same here. The only easy access was to that alignment board (with those ~100
pots :) and the backside of the CRT's... the rest was accessible only by
disassembly of the particle-board-bonded-vinyl case.

...Jim Thompson

Have you melted any coins or started a fire yet with the Fresnell lens?
Wear two pairs of sun glasses or some cutting goggles,
the hot spot is extremely bright.
Mikek

I haven't tried it yet. But it's not circular... JVC calls it "lenticular".

http://en.wikipedia.org/wiki/Lenticular_lens

It's what I would call a "grating". So I'd guess it would focus a line rather
than a spot.

...Jim Thompson
Click to expand...
I think you will find two layers, they come apart, one just lays over
the other, one is a grating the other will be a Fresnell lens. The
grating is on the viewing side the Fresnell is on the inside.
Be careful where you store it, I'll bet there has been a fire somewhere
from poor placement of a large Fresnell lens.
Mikek
 
On 5/10/2012 1:53 PM, amdx wrote:
On 5/10/2012 1:39 PM, Jim Thompson wrote:
On Thu, 10 May 2012 13:26:49 -0500, amdx<amdx@knologynotthis.net> wrote:

On 5/10/2012 11:07 AM, Jim Thompson wrote:
On Thu, 10 May 2012 01:33:44 -0400, "Tom Del Rosso"
td_03@verizon.net.invalid> wrote:


Michael A. Terrell wrote:
Tom Del Rosso wrote:

Michael A. Terrell wrote:
Jim Thompson wrote:

Note that there are only two CRT's shown... the third was the
failure mechanism... leaking oil ;-)


Glycol based coolant. That was a common failure, and fairly
easy to fix.

Too late now. :)


Some people never do any P.M. ;-)

Preventive maintenance on a picture tube?

I tried fixing a TV from the 90's once. I'm sure I could have done
it, if
it had been the least bit designed for mantenance. The damned back and
bottom were molded together, so if you took off the back then it
had no
bottom (or support for the board, which was left dangling) and it kept
threatening to fall back and crack the neck off. I decided it
wasn't worth
the bother or danger.

Same here. The only easy access was to that alignment board (with
those ~100
pots :) and the backside of the CRT's... the rest was accessible
only by
disassembly of the particle-board-bonded-vinyl case.

...Jim Thompson

Have you melted any coins or started a fire yet with the Fresnell lens?
Wear two pairs of sun glasses or some cutting goggles,
the hot spot is extremely bright.
Mikek

I haven't tried it yet. But it's not circular... JVC calls it
"lenticular".

http://en.wikipedia.org/wiki/Lenticular_lens

It's what I would call a "grating". So I'd guess it would focus a line
rather
than a spot.

...Jim Thompson

I think you will find two layers, they come apart, one just lays over
the other, one is a grating the other will be a Fresnell lens. The
grating is on the viewing side the Fresnell is on the inside.
Be careful where you store it, I'll bet there has been a fire somewhere
from poor placement of a large Fresnell lens.
Mikek


Hey Jim, did you find a Fresnell in the 55" tv?
Click to expand...
Mikek
 
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