[PLUG] fixed pattern in laptop screen

[Keith Lofstrom]

On Wed, Sep 22, 2021 at 9:37 PM Denis Heidtmann <denis.heidtmann at gmail.com> wrote:
> I have a Lenovo ThinkPad X240.  It has a vertical stripe ~3 3/4" wide
> starting ~1 1/4 " from the left edge.  If I use a color test screen (
> https://www.ledr.com/colours/multi.htm) it is clearly visible in black
> and grey, barely visible in red and blue, not visible in the other colors.
> What I see in the black is a faint copy of screens I use in various uses:
> the background pattern in one of my emails or the login screen or some
> other, reminiscent of burn-in on a CRT.
>
> Is this fixable?

On Thu, Sep 23, 2021 at 08:38:04AM -0700, Denis Heidtmann wrote:
> Last night I shut the laptop off.  This morning immediately after powering
> up I checked using the color test screen. The pattern did not show up for
> one or two minutes, but then it appeared as it had been.  Maybe this
> observation will help in understanding the issue.

The time delay suggests a thermal problem: loose connecter,
chip attachment, marginal chip behavior.   The first thing
I would check is cooling - assuming there is a fan, is the
air path clean?  The keyboard probably removes with three
or four tiny phillips head screws - you don't need to unplug
the keyboard, but for geeks like us, looking at the stuff
underneath is the Right Thing To Do, and you might see 
something you can fix.

Download the X240 maintenance manual from Lenovo.  Just
because.  It won't help you with a drill-down diagnosis,
but it will show you what's in there, and help you think
about how the machine works.   Find a large stable-flat
plastic ice cube tray to store the screws, and write notes
about which stage of disassembly is in which compartment.

I'd estimate (WAG) your chance of an easy fix (i.e. dust or
loose connector) at 30%, the chance of a complex fix (i.e.
fan or flex cable replacement) is another 30%.   WAG.

If you like how your laptop behaves (and many of the newer
laptops are mostly sucky movie players), used X240 laptops
sell for perhaps $150 on eBay and $200 on craigslist. 
If you own one working and one "hangar queen" spare,
you can swap parts for longer. 

But if this is Not Fun for you, better to do a lot of
research, and find a new non-sucky replacement.  Like you,
I've been spoiled by late-IBM/early Lenovo quality, 
especially the keyboards with tall sculpted keys and the
trackpoint.  There are some intriguing new open-source
laptop design startups, but like everyone the projects
focus on "thin" (who cares?) and touchpads (not tremor-
friendly), compromising keyboard productivity.

My own approach is to stockpile a LOT of old X61 and T60
thinkpads, and swap parts from time to time.  Amusingly,
Asian manufacturers still manufacture new replacement
keyboards for the X60/X61 series, so I have half a dozen
of those.  When all that stuff fails, I probably  must
give up on laptops entirely - my style of intellectual
productivity will no longer be done in North America.

Keith

-- 
Keith Lofstrom          keithl at keithl.com