Lisa jittery screens

From: Jeffrey H. Ingber <jingber_at_ix.netcom.com>
Date: Mon Dec 30 20:16:00 2002

I thought I'd add that the adjustments _do_ hold after the systems cool
down. I ran the machines off and on during the week after the
adjustments without a problem, even during extended on/off cycles - they
just don't seem to hold very well over time.

Jeff


On Mon, 2002-12-30 at 21:16, Jeffrey H. Ingber wrote:
> On Mon, 2002-12-30 at 21:04, John Lawson wrote:
> > You have not siad what you mean by 'jitter', and I am not a Lisa owner..
> > perhaps this is a symptom common to the breed. But I would ask: is it
> > horizontal, vertical, is the raster fragmenting, is the brightness
> > varying?
>
> The "jitter" manifests itself as a very slight (distance-wise) and rapid
> vertical bouncing. The brightness is very consistent.
>
> > Is it a power supply problem that you are adjusting? If so, when it
> > returns, is it time related? Temperature related? I see you have made the
>
> I'm pretty sure it's a power-releated problem as adjusting the supply
> temporarily fixes the problem. Heat may play a role in this, as the
> jitter subsides to some degree when the system heats up. The
> adjustments were made to a "warm" system.
>
> > adjustment in Sept., but nothing since then? If it takes three months for
> > the problem to return, I'd be tempted to adjust for the party, then fix it
> > afterward....
>
> I'll do this for now, but it shouldn't need to be adjusted so often.
> It's a rather arduous process.
>
> >
> > Just my two cents, and worth every penny of it.
> >
> >
> > Cheers and Happy New Year!
> >
> > John
> >
>
Received on Mon Dec 30 2002 - 20:16:00 GMT