Re: [NTLK] Screen Misalignment and request for fixes

From: Marco Mailand (Newton2k1_at_mac.com)
Date: Thu Mar 07 2002 - 03:22:13 EST


> Marco, my friend has an MP120 with an awful case of jaggies (or screen
> misalignment, whatever). Do you think that cleaning display contacts will
> help on this machine? I disassembled it once and cleaned the case where it
> contacts the screen but that didn't helped.
I've so far never striped down a MP1x0 to the pen digitizer contacts and
thus I don't know what materials make the contact. You wrote that you
cleaned the case where it contacts the screen, but the question is: Did you
clean the metal surfaces of both sides too or only the case or maybe only
one side of the contacts? So far I never observed jaggies by myself on a
MP1x0 (120 and 130) but only on the 2k machines. I suspect with all respect
that you haven't touched the right or all parts during your cleaning.
Consider that an oxide layer might be invisible and the contact could look
clean but is not. Another thing is the contact force. As long as contacts
are not spring loaded they will become subject to failure soon or later. In
terms of a contact made by a screw, all clamping elements are acting as
springs. That is e.g. the screw itself which has a certain spring force as
well as the clamped material. If the latter is soft it acts against the
force of the spring and might cause bad contact too. We call that 'contact
force across soft material' which is also suspect to cause bad contact,
especially for rivoted joints.
In case of the MP2k display we find all that: Screw developing the contact
force across a soft plasic body and no spring member which could compensate
expansion. On bending the Newton case the contact force might reduce and the
thread in the plasic body might release a tiny bit which is already enough
to make a gap for dirt and humidity.
Maybe addition of a bit of contact grease is a nice solution to avoid
jaggies forever.

--
With best Regards / Viele Gruesse!

Marco Mailand

http://slsbd.psi.ch/timing http://slsbd.psi.ch/~mmailand/ https://www.paypal.com/refer/pal=YYD3VUXUVD2YG

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