SONY TV model KV-32XBR96S---Bad color purity--help needed

[[email protected]]

SONY TV model KV-32XBR96S

This TV was recently given to my grandson ... I am a while retired from
servicing but still have my test gear.
He expects me to fix it so I have a few queries to make that could speed this
up.We have bought
no manuals as of yet or had the back off.

The set was given to him minus the remote control and no speakers.

Appears to be working and has a nice bright focused picture except the color
purity is terrible.

There are four knobs on each side of the case near to the front close to the CRT
face. I am assuming that these are
where the speakers would normally attach.

1/ Would there need to be speakers in place for the set to have good purity
i.e.Are the speaker mag. fields
compensated for inside the set? Otherwise the speakers placement would not be
significant.

2/ The screen symptoms are a symmetrical wide rainbow from the center screen to
the lower outside corners.

3/ That pattern can be distorted by a magnet but restored by the usual
degaussing methods.

4/ I have no knowledge of the history of this set so I cannot determine if it
has been dropped .
Or worse somebody has been inside "fixing "

5/ At the moment am unable to access the service mode.

I am asking for opinions as to whether this set is fixable ,
If so we can invest in a service manual and a remote control.

Anybody help me out with this ? Thanks

 

[Jumpster Jiver]

SONY TV model KV-32XBR96S

This TV was recently given to my grandson ... I am a while retired from
servicing but still have my test gear.
He expects me to fix it so I have a few queries to make that could speed this
up.We have bought
no manuals as of yet or had the back off.

The set was given to him minus the remote control and no speakers.

Appears to be working and has a nice bright focused picture except the color
purity is terrible.

There are four knobs on each side of the case near to the front close to the CRT
face. I am assuming that these are
where the speakers would normally attach.

1/ Would there need to be speakers in place for the set to have good purity
i.e.Are the speaker mag. fields
compensated for inside the set? Otherwise the speakers placement would not be
significant.

2/ The screen symptoms are a symmetrical wide rainbow from the center screen to
the lower outside corners.

3/ That pattern can be distorted by a magnet but restored by the usual
degaussing methods.

4/ I have no knowledge of the history of this set so I cannot determine if it
has been dropped .
Or worse somebody has been inside "fixing "

5/ At the moment am unable to access the service mode.

I am asking for opinions as to whether this set is fixable ,
If so we can invest in a service manual and a remote control.

Anybody help me out with this ? Thanks

The correct speakers for this TV or any speakers made to be on a TV
would be magnetically shielded so that should not matter.
The two main possibilities are a problem with the degaussing circuit or
the set has been dropped and the shadow mask has shifted.
You should first check and maybe resolder the degaussing thermistor.
If the degaussing circuit seems to be working correctly then it's
probably the CRT.
One way to be sure is to disconnect the internal degaussing coil and
manually degauss it from outside the set. If that doesn't work chances
are it was dropped and the CRT is toast.

 

[justmanuals]

http://www.justmanuals.com/sony-trinitron-color-27xbr96s-32xbr96s-chassis-parts-service-p-2315.html
$9.99 and instant download

 

[Peter Kolbe]

Just fixed a the same problem in a set the other day - bad PTC (Three-legged
device near where the degauss coil connects to the board)

Pulled one of a SVGA monitor, and popped it in the set, and at the next
powercycle it was sorted out.

Peter

 

[[email protected]]

If the problem was the internal degauss I would expect that use of my external
degausser would fix the display. It does not , but thanks for the suggestion.
I am leaning toward a "bad" CRT for now but will try a few things more before
salvaging parts.

 

[Jerry G.]

If the CRT has not been damaged from a hard knock or a drop, most likely the
thermosistor for the degausser has to be replaced. These are universally
available from most electronics parts suppliers for TV service, or from the
original manufacture parts department.

I doubt the purity alignment is out, unless someone messed with the magnet
and yoke assembly. This is not something the average service tech would have
an easy time to re-align unless he has had a lot of practice.

You can remove the old one, and get a manual degaussed coil from an
electronics supplier. But, this is not a convenient way to use the TV set.

--

Jerry G.
======


SONY TV model KV-32XBR96S

This TV was recently given to my grandson ... I am a while retired from
servicing but still have my test gear.
He expects me to fix it so I have a few queries to make that could speed
this
up.We have bought
no manuals as of yet or had the back off.

The set was given to him minus the remote control and no speakers.

Appears to be working and has a nice bright focused picture except the color
purity is terrible.

There are four knobs on each side of the case near to the front close to the
CRT
face. I am assuming that these are
where the speakers would normally attach.

1/ Would there need to be speakers in place for the set to have good purity
i.e.Are the speaker mag. fields
compensated for inside the set? Otherwise the speakers placement would not
be
significant.

2/ The screen symptoms are a symmetrical wide rainbow from the center screen
to
the lower outside corners.

3/ That pattern can be distorted by a magnet but restored by the usual
degaussing methods.

4/ I have no knowledge of the history of this set so I cannot determine if
it
has been dropped .
Or worse somebody has been inside "fixing "

5/ At the moment am unable to access the service mode.

I am asking for opinions as to whether this set is fixable ,
If so we can invest in a service manual and a remote control.

Anybody help me out with this ? Thanks

 

[Art]

Due to the arpaturer grill assembly in SONY CRTS the manufacturer highly
recommends not using external degaussing devices due to the fact that
incorectly applied can deform the thin arpature grill assembly. These CRTS
do not use a shadow mask arrangment. Physical thumps, not necessairly being
dropped, also can delocate the arpaturer grill asselbly rendering the CRT
unusable. FWIW: get the proper degauss thermistor and correct AC fuse (6.3
Amp) and have at it.

 

[William Sommerwerck]

Due to the aperture grill in Sony CRTs, the manufacturer highly
recommends not using external degaussing devices due to the
fact that incorectly applied can deform the thin aperture grill.

Aperture is the correct spelling.

This appears to be what happened to my Sony. While degaussing the CRT with a
bulk tape eraser, the eraser was accidentally shut off near the tube, which
then developed a small area of permanent impurity.

 

[Billy L Jones]

Visit http://fletchersite.com . These guys will tell you how to fix the
problem and even provide the full service manual.

 

[[email protected]]

Due to the arpaturer grill assembly in SONY CRTS the manufacturer highly
recommends not using external degaussing devices due to the fact that
incorectly applied can deform the thin arpature grill assembly. These CRTS
do not use a shadow mask arrangment. Physical thumps, not necessairly being
dropped, also can delocate the arpaturer grill asselbly rendering the CRT
unusable. FWIW: get the proper degauss thermistor and correct AC fuse (6.3

<snip>

In 86 I started at Sony Broadcast and got a tour of the San Diego
plant where tubes and TVs were manufactured and saw a guy whose job it
was to hit the face of each tube on the suspended conveyor with a
rubber mallet. Some years later we had run an external degaussing coil
on a BVM1910 monitor and 'deformed' the aperture grill by apparently
criss-crossing some of the strips. Since it was trashed, I smacked it
wih a mallet like I saw in San Diego. After several serious hits, the
strips untangled and worked normally again. BTW the replacement cost
on that CRT was $2000.

This failure was _not_ broad blotches but localized disruptions of
only a few stripes.

GG

 

[[email protected]]

<snip>

In 86 I started at Sony Broadcast and got a tour of the San Diego
plant where tubes and TVs were manufactured and saw a guy whose job it
was to hit the face of each tube on the suspended conveyor with a
rubber mallet. Some years later we had run an external degaussing coil
on a BVM1910 monitor and 'deformed' the aperture grill by apparently
criss-crossing some of the strips. Since it was trashed, I smacked it
wih a mallet like I saw in San Diego. After several serious hits, the
strips untangled and worked normally again. BTW the replacement cost
on that CRT was $2000.

This failure was _not_ broad blotches but localized disruptions of
only a few stripes.

GG

Was that bashing done with power on to the tube ?
This rubber hammer bashing technique is near the bottom on my" to do" list right
before I take the CRT outside and use it for target practice (a safe distance of
course).
On the other hand I might just stick the set outside when the temperature is 22
degrees below zero just to see what happens (the little strips should maybe
contract a bit ). Also been wondering about trying a vibrator.

 

[Michael A. Terrell]

Visit http://spammer.com . These guys are ignorant spammers.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Andy Cuffe]

Was that bashing done with power on to the tube ?
This rubber hammer bashing technique is near the bottom on my" to do" list right
before I take the CRT outside and use it for target practice (a safe distance of
course).
On the other hand I might just stick the set outside when the temperature is 22
degrees below zero just to see what happens (the little strips should maybe
contract a bit ). Also been wondering about trying a vibrator.

Try unplugging the degaussing coil and then degaussing it. I've seen
Sony sets where manual degaussing didn't help until the degaussing
coil was unplugged from the defective degaussing circuit.

I've seen Trinitron CRTs with aperture grill wires that were stuck
together and it looks like sharp vertical lines of incorrect purity,
not large areas. I've only ever seen it on a computer monitor. I
think the wires are too far apart for this to happen on a TV.

The aperture grill functions exactly the same way as a shadow mask.
It's just a sheet of metal with thin slits cut in it. A shadow mask
is made of similar metal, but has slots or holes instead of slits.
Andy Cuffe

[email protected]

 

[[email protected]]

wrote in message

Was that bashing done with power on to the tube ?
This rubber hammer bashing technique is near the bottom on my" to do" list right
before I take the CRT outside and use it for target practice (a safe distance of
course).
On the other hand I might just stick the set outside when the temperature is 22
degrees below zero just to see what happens (the little strips should maybe
contract a bit ). Also been wondering about trying a vibrator.

Sure with power on. How else would you know when to stop?. BTW they
were NOT taps but pretty solid hits. Of course you want to be VERY
SURE there are no metal shavings or grit in the mallet !!

The BVM 1910 had a hi resolution tube to show noise in a standard def
signal, similar to a computer monitor but with SMPTE phosphors.
Consumer TV tubes have much coarser aperture which hides HF noise and
is easier to build and has P22 phosphors.

GG
GG