28" CRT telly fallen on floor. Is it salvagable?

"Stephen Wolstenholme" wrote in message
news
On Fri, 18 Jul 2008 10:25:38 +0100, "Ivan"
wrote:

Quite a common fault on certain Sony models [AE1 chassis] was for the scan
coils on the CRT neck to work loose, creating purity errors around the
tube
face, definitely worth geting checked out to see if they have been
dislodged
by the large mechanical shock, however it's not something I would
recommend
for the uninitiated, as large and dangerous voltages can still be present
around this tube area, even after the set has been switched off and
disconnected from the mains.

CRT's can retain a charge for days. Many years ago I worked in a TV
factory. It was quite common to be zapped by a new CRT when it was
removed from its box. The tube would still be charged from being
tested in the CRT factory. After a bit of experience I made sure the
final anode was flashed over to the tube coating when unpacking the
box. Those were only small B&W tubes.

Steve


IMO the worst thing of all is the reservoir capacitor which can hold around
320 Volts [sometimes for over a day] fitted in many switch mode power
supplies.
The usual procedure is always to apply a bleed resistor across the terminals
before attempting any kind of service.. but come on lads how many times have
you forgotten!. only to find out the hard way by having chunks of burning
flesh removed, accompanied by that sick and trembling feeling and in many
cases a completely decimated power supply, all because the manufacturer
thought to save a penny by not incorporating a bleed resistor into the
design.

In message , Graham.
wrote


"Marky P" wrote in message
.. .
My brother had to move his 28" Sony CRT telly the other day to do some
decorating. It fell over on it's front with a amighty crash! Upon
rescuing it, the screen has a big splodge of green on one side and
purple on the other. He's tried switching it on & off (properly) to
degause it but no effect. I thought maybe the shadow mask had
distorted. Is it fixable?

Marky P.


No Marky, sorry. You've gone and buckled the aperture grille
http://en.wikipedia.org/wiki/Aperture_grille
Someone will no doubt tell you that the screen is magnetised suggest you
degauss it won't work in this case, trust me.


In that case percussion methods may fix it. Hit the side of the TV hard
with the flat of your hand.

If it requires de-gausing and switching off at the plug doesn't do it
then get a large magnet (old speaker magnet). Suspend it from a loop of
string. Spin the magnet. Whilst it is still spinning move it close to
the screen and then slowly away from the screen.

--
Alan
news2006 {at} amac {dot} f2s {dot} com

On Fri, 18 Jul 2008 13:40:33 +0100, Alan
wrote:

In message , Graham.
wrote


"Marky P" wrote in message
. ..
My brother had to move his 28" Sony CRT telly the other day to do some
decorating. It fell over on it's front with a amighty crash! Upon
rescuing it, the screen has a big splodge of green on one side and
purple on the other. He's tried switching it on & off (properly) to
degause it but no effect. I thought maybe the shadow mask had
distorted. Is it fixable?

Marky P.


No Marky, sorry. You've gone and buckled the aperture grille
http://en.wikipedia.org/wiki/Aperture_grille
Someone will no doubt tell you that the screen is magnetised suggest you
degauss it won't work in this case, trust me.


In that case percussion methods may fix it. Hit the side of the TV hard
with the flat of your hand.

If it requires de-gausing and switching off at the plug doesn't do it
then get a large magnet (old speaker magnet). Suspend it from a loop of
string. Spin the magnet. Whilst it is still spinning move it close to
the screen and then slowly away from the screen.

Yeah, I know how to de-gause as I did it at a telly repair place when
I was 16 on work experience :-) Had a proper de-gauser then, but
maybe I will try a speaker magnet.

Marky P.

On Fri, 18 Jul 2008 10:25:38 +0100, "Ivan"
wrote:


"Marky P" wrote in message
.. .
My brother had to move his 28" Sony CRT telly the other day to do some
decorating. It fell over on it's front with a amighty crash! Upon
rescuing it, the screen has a big splodge of green on one side and
purple on the other. He's tried switching it on & off (properly) to
degause it but no effect. I thought maybe the shadow mask had
distorted. Is it fixable?

Marky P.


Quite a common fault on certain Sony models [AE1 chassis] was for the scan
coils on the CRT neck to work loose, creating purity errors around the tube
face, definitely worth geting checked out to see if they have been dislodged
by the large mechanical shock, however it's not something I would recommend
for the uninitiated, as large and dangerous voltages can still be present
around this tube area, even after the set has been switched off and
disconnected from the mains.

I learned no end when doing Work Experience for two weeks when I was
16. Including what happens when you snip the cable that goes to the
tube without draining the power to the chassis first. I tried pulling
it off the tube, but it was stuck, so I cut it & WALLOP! Got a
reasonable jolt there!

Marky P.

"Alan" wrote in message
...


In that case percussion methods may fix it. Hit the side of the TV hard
with the flat of your hand.

\


or a tambourine ?


--
Gareth.

that fly...... is your magic wand....

"tony sayer" wrote in message
...
In article , Brian Gaff
scribeth thus
Not always the case but for various reasons, its a mess if it canbe sorted
at all. Always duct tape a pillow to the front of tvs if moving them as
they
are nearly always front heavy if of the crt kind.

When I was in the TV trade thats the way we used to transport them in
estate cars and Vans either face down on the seats or on very large
chunks of foam rubber...

Same here - always face down on foam in the back of the trusty Avenger
estate we all used - later replaced by a Cavalier estate.

"Doctor D" wrote in message
...

"tony sayer" wrote in message
...
In article , Brian Gaff
scribeth thus
Not always the case but for various reasons, its a mess if it canbe
sorted
at all. Always duct tape a pillow to the front of tvs if moving them as
they
are nearly always front heavy if of the crt kind.

When I was in the TV trade thats the way we used to transport them in
estate cars and Vans either face down on the seats or on very large
chunks of foam rubber...

Same here - always face down on foam in the back of the trusty Avenger
estate we all used - later replaced by a Cavalier estate.

With me it was Vauxhall Vivas followed by Chevettes, Maestros then Astras
and I'm sure there was a Mini Metro (I kid you not) in there somewhere
when the company was strapped for cash. Oh, and before the Vivas it was
Hillman Huskies but that was before my time.
So the quiz question is, who did I work for?

--
Graham.

%Profound_observation%

On Sat, 19 Jul 2008 15:10:41 +0100, "Graham." wrote:



With me it was Vauxhall Vivas followed by Chevettes, Maestros then Astras
and I'm sure there was a Mini Metro (I kid you not) in there somewhere
when the company was strapped for cash. Oh, and before the Vivas it was
Hillman Huskies but that was before my time.
So the quiz question is, who did I work for?

Henry Wigfall

Derek

In message , Graham.
writes
Oh, and before the Vivas it was
Hillman Huskies but that was before my time.
So the quiz question is, who did I work for?

Granada Bedford used to have Huskies, yes?


--
Bill

"Graham." wrote in message
...

With me it was Vauxhall Vivas followed by Chevettes, Maestros then Astras
and I'm sure there was a Mini Metro (I kid you not) in there somewhere
when the company was strapped for cash. Oh, and before the Vivas it was
Hillman Huskies but that was before my time.
So the quiz question is, who did I work for?


Mastercare?