Perq 2T1 display fault

From: Jules Richardson <julesrichardsonuk_at_yahoo.co.uk>
Date: Mon Feb 9 05:37:18 2004

On Sun, 2004-02-08 at 01:22, R. D. Davis wrote:
> Quothe Jules Richardson, from writings of Sat, Feb 07, 2004 at
> 11:35:06PM +0000:
>
> > Got a Perq 2T1 with the KME 1514 portrait monitor - the display on the
> > front of the unit gets as far as 999 on power-up so it's looking
> > reasonably healthy. Only problem is an unstable display; it seems to be
> > missing out every 4th or so scanline, plus there's some horizontal
> > instability (I can see what appear to be characters on the display, but
> > they aren't readable at all)
>
> One of my PERQ T2's had a similar problem years ago, but that was with
> the 19" landscape Moniterm monitor. To solve the problem, I simply
> replaced the PLL chip in the monitor.

Hmm, there isn't a lot in the way of ICs in these monitors by the looks
of it - I noticed an LS device which is presumably part of the sync
separation circuitry, then there was a TDA1170 device on the board too.
I seem to remember those are used in Microvitec CUB monitors and are
prone to failure (I have some spares somewhere), but I can't remember
what sort of symptoms they give when they fail.


> Did you try reseating the boards or just letting the maching run for
> hours and hours? Is the problem intermittent?

yes, yes and no :-)

It doesn't seem to be temperature-related anyway. At least the HV
circuitry is still alive, so fingers crossed it's fixable...

> > Oh, and if anyone's dishing out Perq wisdom there's also a Perq 1 with a
> > display fault too - on that one the image is centered on the screen, but
> > squashed into about 80% of the normal width, and maybe 10% of normal
> > height. It's also very non-rectangular in nature.
>
> Never experienced that problem with my PERQ-1 systems... the only
> major thing that ever went wrong with them were head crashes. :-( For
> those not familiar with these machines, they had either SA4004 or
> SA4008 14", 12MB and 24MB, hard drives... not easy to find
> replacements for, alas.

Yuck. Not sure how alive that one is. I can tell they're both going to
be another couple of those headache machines where I can't work out how
to back up the data ready for when the drives do eventually die :(

We may have drive replacements for the Perq-1 in store, but I'm betting
we don't have original install media...

cheers

Jules
Received on Mon Feb 09 2004 - 05:37:18 GMT