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Laptop screen - Intermittent red/green stripes

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Anonymous
a b D Laptop
June 6, 2004 7:36:43 AM

Archived from groups: comp.sys.laptops (More info?)

Hi,

The screen on my 4 year old Toshiba Satellite 3000-400 (3000-S353 in
the USA I think) has recently developed a problem. Whenever you tilt
the screen backward or forward, or bend it very slightly, a vertical
red or green strip intermittently appears about 4cm from the left of
the screen.

Also, every now and then, the backlight cuts out, and will only come
back on if you completely cut off and then reconnect power to the
unit, i.e. unplug the power adapter and remove the battery.

My feeling is that there is some kind of short connection in the TFT
wiring harness, and that every now and then, it all gets too much and
trips some kind of circuit breaker, which turns off the backlight.

Perhaps then, this could all be remedied by replacing the TFT cable?

I'd appreciate any thoughts/advice you'd be able to offer.

Thanks in advance,

Rob
June 6, 2004 11:37:33 PM

Archived from groups: comp.sys.laptops (More info?)

I'm not sure what the exact problem could be; that's the thing about
laptops, quite hard to diagnose problems sometimes as everything's confined
into a small space.

It's 4 years old though, so you've got good use out of it!

I'd take it to a local computer shop that can deal with laptops and see what
they can do. If they say 'the screen needs replacing' say you're experienced
with computers and you know for a fact that's not the case, it would likely
cost too much to replace the screen!

Hopefully it'll be simple...

"Robert Morgan" <robbiemorgan@yahoo.com> wrote in message
news:6d612270.0406060236.3a90a137@posting.google.com...
> Hi,
>
> The screen on my 4 year old Toshiba Satellite 3000-400 (3000-S353 in
> the USA I think) has recently developed a problem. Whenever you tilt
> the screen backward or forward, or bend it very slightly, a vertical
> red or green strip intermittently appears about 4cm from the left of
> the screen.
>
> Also, every now and then, the backlight cuts out, and will only come
> back on if you completely cut off and then reconnect power to the
> unit, i.e. unplug the power adapter and remove the battery.
>
> My feeling is that there is some kind of short connection in the TFT
> wiring harness, and that every now and then, it all gets too much and
> trips some kind of circuit breaker, which turns off the backlight.
>
> Perhaps then, this could all be remedied by replacing the TFT cable?
>
> I'd appreciate any thoughts/advice you'd be able to offer.
>
> Thanks in advance,
>
> Rob
June 6, 2004 11:37:34 PM

Archived from groups: comp.sys.laptops (More info?)

How can you be so sure that the screen does not need to be replaced?
What symptoms would a failed screen show? I have a laptop that blanks
out and then returns to a perfect display when I move the LCD/cover.
The screen goes gray, not black as it does when powered down. I took
it to a shop for diagnosis and they said the LCD needed to be
replaced. I said no thanks, too much money to spend on a four year old
laptop. Two replies in another thread said either replace the LCD
harness or look for loose connections. Any additional thoughts would
be appreciated.

Regards, hawk

Dave wrote:
> I'm not sure what the exact problem could be; that's the thing about
> laptops, quite hard to diagnose problems sometimes as everything's confined
> into a small space.
>
> It's 4 years old though, so you've got good use out of it!
>
> I'd take it to a local computer shop that can deal with laptops and see what
> they can do. If they say 'the screen needs replacing' say you're experienced
> with computers and you know for a fact that's not the case, it would likely
> cost too much to replace the screen!
>
> Hopefully it'll be simple...
>
Related resources
Anonymous
a b D Laptop
June 7, 2004 9:14:17 AM

Archived from groups: comp.sys.laptops (More info?)

Similar situation for me. I'm reluctant to junk the screen as, when
the stripes aren't showing, the display is perfect! But then if the
problem lies in the electronics that are integrated into the screen
and not servicable, then I guess there's no other option.

I guess I'll probably try a new cable first.

Rob

hawk <hawk@spamex.com> wrote in message news:<10c72d2rab8gg09@corp.supernews.com>...
> How can you be so sure that the screen does not need to be replaced?
> What symptoms would a failed screen show? I have a laptop that blanks
> out and then returns to a perfect display when I move the LCD/cover.
> The screen goes gray, not black as it does when powered down. I took
> it to a shop for diagnosis and they said the LCD needed to be
> replaced. I said no thanks, too much money to spend on a four year old
> laptop. Two replies in another thread said either replace the LCD
> harness or look for loose connections. Any additional thoughts would
> be appreciated.
>
> Regards, hawk
>
> Dave wrote:
> > I'm not sure what the exact problem could be; that's the thing about
> > laptops, quite hard to diagnose problems sometimes as everything's confined
> > into a small space.
> >
> > It's 4 years old though, so you've got good use out of it!
> >
> > I'd take it to a local computer shop that can deal with laptops and see what
> > they can do. If they say 'the screen needs replacing' say you're experienced
> > with computers and you know for a fact that's not the case, it would likely
> > cost too much to replace the screen!
> >
> > Hopefully it'll be simple...
> >
Anonymous
a b D Laptop
June 8, 2004 3:47:49 AM

Archived from groups: comp.sys.laptops (More info?)

I think that you are dealing with two separate and unrelated problems.

The stripes are most likely caused by an intermittent problem with the
LCD panel itself. Could be bad part, bad solder connection or a bad
"bond" in the flat ribbon cables connecting the LCD panel's drivers to
the glass itself (failure of the ribbon cable to glass bond is a common
problem). There is a much slimmer chance that it's the cable connecting
the lid to the base, but I think that's unlikely from your description.
From your description, some aspect of the problem is almost certainly
mechanical.

None of this has anything to do with the inverter which powers the
backlight. The inverter is a totally separate PC board in the lid, and
it's only connection to the LCD panel is to the flourescent lamps that
it powers. But from your description, it's inverter failure that is
killing the backlight.

If this really is two separate problems, it's going to be expensive to
fix both of them, as you may be talking about a new LCD panel and a new
inverter.


Robert Morgan wrote:

> Hi,
>
> The screen on my 4 year old Toshiba Satellite 3000-400 (3000-S353 in
> the USA I think) has recently developed a problem. Whenever you tilt
> the screen backward or forward, or bend it very slightly, a vertical
> red or green strip intermittently appears about 4cm from the left of
> the screen.
>
> Also, every now and then, the backlight cuts out, and will only come
> back on if you completely cut off and then reconnect power to the
> unit, i.e. unplug the power adapter and remove the battery.
>
> My feeling is that there is some kind of short connection in the TFT
> wiring harness, and that every now and then, it all gets too much and
> trips some kind of circuit breaker, which turns off the backlight.
>
> Perhaps then, this could all be remedied by replacing the TFT cable?
>
> I'd appreciate any thoughts/advice you'd be able to offer.
>
> Thanks in advance,
>
> Rob
Anonymous
a b D Laptop
June 8, 2004 3:54:26 AM

Archived from groups: comp.sys.laptops (More info?)

Hawk, your problem sounds like a bad cable connecting the LCD panel to
the video board in the base (could be just a loose connector, if you are
lucky).

His problem sounds more like an actual panel defect.

If you want to know "How can you be so sure ....", well, I don't claim
to be 100% sure. But I have an EE degree and have been working with
these things for more than a decade, and when you understand HOW they
work -- at an engineering level -- you are more likely to correctly
evaluate a symptom in terms of the things that would be likely to cause
it. However, you can't be 100.0% sure, especially without even having
seen the unit in question.


hawk wrote:

> How can you be so sure that the screen does not need to be replaced?
> What symptoms would a failed screen show? I have a laptop that blanks
> out and then returns to a perfect display when I move the LCD/cover. The
> screen goes gray, not black as it does when powered down. I took it to a
> shop for diagnosis and they said the LCD needed to be replaced. I said
> no thanks, too much money to spend on a four year old laptop. Two
> replies in another thread said either replace the LCD harness or look
> for loose connections. Any additional thoughts would be appreciated.
>
> Regards, hawk
>
> Dave wrote:
>
>> I'm not sure what the exact problem could be; that's the thing about
>> laptops, quite hard to diagnose problems sometimes as everything's
>> confined
>> into a small space.
>>
>> It's 4 years old though, so you've got good use out of it!
>>
>> I'd take it to a local computer shop that can deal with laptops and
>> see what
>> they can do. If they say 'the screen needs replacing' say you're
>> experienced
>> with computers and you know for a fact that's not the case, it would
>> likely
>> cost too much to replace the screen!
>>
>> Hopefully it'll be simple...
>>
>
Anonymous
a b D Laptop
June 8, 2004 4:03:58 AM

Archived from groups: comp.sys.laptops (More info?)

The most likely single cause (not the only one, or even the only common
one) is in an intermittent ribbon-cable to glass (panel) bond. In
theory, this can be fixed, but it's rarely done outside of an LCD
factory or a VERY specialized repair facility. There are some places
that do offer this service, but it's not cheap, it's only slightly
cheaper than a new panel.


Robert Morgan wrote:

> Similar situation for me. I'm reluctant to junk the screen as, when
> the stripes aren't showing, the display is perfect! But then if the
> problem lies in the electronics that are integrated into the screen
> and not servicable, then I guess there's no other option.
>
> I guess I'll probably try a new cable first.
>
> Rob
>
> hawk <hawk@spamex.com> wrote in message news:<10c72d2rab8gg09@corp.supernews.com>...
>
>>How can you be so sure that the screen does not need to be replaced?
>>What symptoms would a failed screen show? I have a laptop that blanks
>>out and then returns to a perfect display when I move the LCD/cover.
>>The screen goes gray, not black as it does when powered down. I took
>>it to a shop for diagnosis and they said the LCD needed to be
>>replaced. I said no thanks, too much money to spend on a four year old
>>laptop. Two replies in another thread said either replace the LCD
>>harness or look for loose connections. Any additional thoughts would
>>be appreciated.
>>
>>Regards, hawk
>>
>>Dave wrote:
>>
>>>I'm not sure what the exact problem could be; that's the thing about
>>>laptops, quite hard to diagnose problems sometimes as everything's confined
>>>into a small space.
>>>
>>>It's 4 years old though, so you've got good use out of it!
>>>
>>>I'd take it to a local computer shop that can deal with laptops and see what
>>>they can do. If they say 'the screen needs replacing' say you're experienced
>>>with computers and you know for a fact that's not the case, it would likely
>>>cost too much to replace the screen!
>>>
>>>Hopefully it'll be simple...
>>>
Anonymous
a b D Laptop
June 8, 2004 6:28:38 AM

Archived from groups: comp.sys.laptops (More info?)

Hi Barry,

Thanks for the info - I think you've hit the nail on the head.

Having taken off the screen cover, I find nothing happens if I move
the base to LCD cables around. The stripe only appears if I bend the
screen very slightly, bend it one way and I get a red stripe, bend it
the other and I get green.

So it sounds like you're right, the best guess is it's a problem with
the internal wiring. Looks like it'll be a new screen or a new machine
then! Either that or I live with it 'til it really dies!

Interestingly, I also noticed a small crack in the screen cover, which
I fixed with superglue. I could be imagining it, but it seems the
problem at least occurs less frequently now. Is it possible the crack
was allowing the screen to flex more than it should?

Thanks,

Rob
June 8, 2004 11:28:08 AM

Archived from groups: comp.sys.laptops (More info?)

Thanks for the reply. I took things apart and checked the ribbon cable
connections. Everything looked OK, but when I looked closely at the
larger connector on the electronics board in the LCD panel, I noticed
a small tear in the ribbon cable near one edge. Unfortunately, when I
was messing with it, the connector broke off of the board, bummer! It
is probably repairable by someone skilled at soldering very small
connections, but beyond me.

Regards, hawk


Barry Watzman wrote:
> Hawk, your problem sounds like a bad cable connecting the LCD panel to
> the video board in the base (could be just a loose connector, if you are
> lucky).
>
June 8, 2004 12:42:43 PM

Archived from groups: comp.sys.laptops (More info?)

chances are its just the flex cable that connects the panel to the system
board. the fact it occurs/corrects itself when moving the panel would
indicate this,try reseating the cable or better still get it replaced
"hawk" <hawk@spamex.com> wrote in message
news:10c72d2rab8gg09@corp.supernews.com...
> How can you be so sure that the screen does not need to be replaced?
> What symptoms would a failed screen show? I have a laptop that blanks
> out and then returns to a perfect display when I move the LCD/cover.
> The screen goes gray, not black as it does when powered down. I took
> it to a shop for diagnosis and they said the LCD needed to be
> replaced. I said no thanks, too much money to spend on a four year old
> laptop. Two replies in another thread said either replace the LCD
> harness or look for loose connections. Any additional thoughts would
> be appreciated.
>
> Regards, hawk
>
> Dave wrote:
> > I'm not sure what the exact problem could be; that's the thing about
> > laptops, quite hard to diagnose problems sometimes as everything's
confined
> > into a small space.
> >
> > It's 4 years old though, so you've got good use out of it!
> >
> > I'd take it to a local computer shop that can deal with laptops and see
what
> > they can do. If they say 'the screen needs replacing' say you're
experienced
> > with computers and you know for a fact that's not the case, it would
likely
> > cost too much to replace the screen!
> >
> > Hopefully it'll be simple...
> >
>
!