Thinkpad 750Cs Lower Half of Screen Oddity

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3 total messages Started by David Longley Sun, 21 Apr 1996 00:00

#3046

Author: David Longley
Date: Sun, 21 Apr 1996 00:00

17 lines
1405 bytes

I have an IBM Thinkpad 750Cs, Dual Scan Colour notebook. Over the pst two
days it's started to show some odd symptoms in the lower half of the display
at boot up. It's corrected by a light tap to the side of the lid.

Symptom: Vertical lines appear on the lower half of the display, and they
seem to be the three primary colours. It's as if the convergence has drifted,
though I undrstand that this is not the way a dual scan works.

I plan to take it to an IBM service point as it is still under warranty. The
first year was only up last November, and I understand it is covered by a 3
year warranty.

Can someone explain what it's likely to be?


-- 
David Longley

Re: Thinkpad 750Cs Lower Half of Screen Oddity

#3043

Author: Mike Fleming
Date: Sun, 21 Apr 1996 00:00

18 lines
1645 bytes

In article <830106236snz@longley.demon.co.uk>
           David@longley.demon.co.uk "David Longley" writes:

> I have an IBM Thinkpad 750Cs, Dual Scan Colour notebook. Over the pst two
> days it's started to show some odd symptoms in the lower half of the display
> at boot up. It's corrected by a light tap to the side of the lid.
> 
> Symptom: Vertical lines appear on the lower half of the display, and they
> seem to be the three primary colours. It's as if the convergence has drifted,
> though I undrstand that this is not the way a dual scan works.

Perhaps the ribbon cable running through the hinge?

-- 
Mike (DF) Fleming      MAG #79794     DoD #4446      Greenpeace #567708F
                       JKLO #004      KotWP7         UKMC #9
Which of these well-meaning groups will look out for the homeless snail
And who is going to save the slug ere it reaches the end of its trail?

Re: Thinkpad 750Cs Lower Half of Screen Oddity

#3044

Author: Sam Goldwasser
Date: Sun, 21 Apr 1996 00:00

20 lines
1743 bytes

In article <830106236snz@longley.demon.co.uk> David Longley <David@longley.demon.co.uk> writes:

>   I have an IBM Thinkpad 750Cs, Dual Scan Colour notebook. Over the pst two
>   days it's started to show some odd symptoms in the lower half of the display
>   at boot up. It's corrected by a light tap to the side of the lid.

>   Symptom: Vertical lines appear on the lower half of the display, and they
>   seem to be the three primary colours. It's as if the convergence has drifted,
>   though I undrstand that this is not the way a dual scan works.

There is no such thing as convergence on an LCD display.  There are
row and column drivers, however, and if the timing is messed up or certain
logic signals do not get where they are supposed to go or get stuck, the
pixels may not be properly displayed or line up.  In your case, it sounds
like you have bad solder connections to one or more of these driver chips.
Going beyond this would just be wild speculation.  Taking it in for repair
is probably the only real option since getting inside those LCD displays
is a real treat.

--- sam

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