Red/Green/Blue stripes on screen.

insurance job

: Greetings group.
: Philips ctv model 25GX1886/75R.
: Tv fell off its perch face first onto the floor (around 40cm).
:
: Power switch assembly had been dislodged.
: After remounting the switch, ctv still would not turn on.
:
: With the help of a magnifying glass, I found
: cracks through around 18 tracks which were repaired.
:
: CTV now turned on, but the picture could barely be seen through
: many vertical red/green/blue stripes right across the screen.
: Sound is fine.
:
: Shorting each gun to ground did not produce only a red, green or blue
: screen.
: It only changed the strips slightly.
:
: I suspect the shadow mask has moved inside the picture tube.
:
: What do you think?
:
:
: Thanking you,
: Russell Griffiths.
:

never let a TV fall off.



Greetings group.
Philips ctv model 25GX1886/75R.
Tv fell off its perch face first onto the floor (around 40cm).

Power switch assembly had been dislodged.
After remounting the switch, ctv still would not turn on.

With the help of a magnifying glass, I found
cracks through around 18 tracks which were repaired.

CTV now turned on, but the picture could barely be seen through
many vertical red/green/blue stripes right across the screen.
Sound is fine.

Shorting each gun to ground did not produce only a red, green or blue
screen.
It only changed the strips slightly.

I suspect the shadow mask has moved inside the picture tube.

What do you think?


Thanking you,
Russell Griffiths.

On 9 Apr 2005 05:56:25 -0700, " snipped-for-privacy@hotmail.com"


It's indeed possible, and sounds likely to me from the symptoms - but
on the other hand I have seen much more violent treatment than this,
worst being a 25" CRT (its enclosure falling from a moving vehicle at
about 80km/h onto the road) - and convergence/purity was 100%
afterwards, so I would consider a 40 cm fall to be relatively minor by
comparison, but you never know with these things.  Then again if it
was onto a hard concrete floor - its a different matter too :)

I presume you have tried the degaussing wand, adjusting the purity
rings (if it has any) on the tube neck,  making sure the yoke is still
aligned on the neck properly, and such ?.  

Checking for cracks, damaged or dislodged components on other boards,
damaged or dry solder joints caused by mechanical stresses of the fall
on heavy components etc might be an interesting exercise too come to
think of it.

Falling off the back of a moving vehicle onto a road at 80km/h versus 40cm
to a concrete floor.
Hmmmm.... if I was the TV I think I'd opt for the later option. :)
BTW what brand of TV survived the 80km/h road ordeal?

On Sun, 10 Apr 2005 13:04:52 +0800, "Alan Rutlidge"


It was in an arcade game machine, plywood case with the tube directly
mounted on a plywood frame inside.

The cabinet broke apart at the joins but didnt completely disassemble
into separate pieces, (possibly due to internal wiring harnesses and
large metal angles bolted through at some of the joins) and managed to
hold together enough to not let the tube fly out.  By some miracle -
no part of it managed to hit the fragile CRT neck.

I do have a photo of the thing after the accident lying around
somewhere, showing what a close call it was !

The monitor type was a "glendale electronics" brand.  I have also seen
this identical tube/yoke type used in some of the european made
"fujitsu" 26" sets from the early 1990's or thereabouts.  TOtally
different chassis though :)