[rescue] Did i nuke my SS20?

[Jonathan Chapman]

Peter,

I've had issues with new M48T08s in my SPARCclassic and SS10. They store NVRAM
values just fine but the clock won't keep time and causes a fault during
self-test that results in no automatic boot.

Similar thing with M48T02s on sun4c.

Thanks,
Jonathan

bbbbbbb Original Message bbbbbbb

On Monday, August 2nd, 2021 at 12:24, Peter Stokes <peter at ashlyn.co.uk>
wrote:

> Hi
>
> There was a curious comment re modern M48T08 not working in old Sun kit due
to
>
> a timing issue. I have bought a fair number over the last few years from
the
>
> official distis such as Farnell and Mouser and had zero issues. The new
M48T02
>
> is a different matter and most versions of OBP have an issue from what I
>
> remember when testing them.
>
> FYI the official chip for the SS20 is the M48T18 not the M48T08, but in my
>
> experience they are interchangeable.
>
> Peter
>
> Sent from my iPad
>
> > On 2 Aug 2021, at 17:16, Romain Dolbeau romain at dolbeau.org wrote:
> >
> > o;?Le lun. 2 aoC;t 2021 C 16:50, Ray Brooks ray.userinterface at gmail.com
>
> a
>
> > C)crit :
> >
> > > The good news is that the motherboard isn't nuked.
> >
> > Good news indeed :-) Those were built to last, fortunately.
> >
> > > I've managed to get it to POST via serial by stripping it back to the
> > >
> > > absolute bare bones as suggested by Romain.
> > >
> > > I need to do some more digging around here to fully track down the
problem
> > >
> > > but the good news is that nothing important seems to be broken. Phew!
> >
> > If you reach the PROM prompt, you're all good if it's with the new NVRAM.
> >
> > You just need to full-reset it as per the NVRAM faq (i.e.,
> >
> > set-defaults, then invalidate the checkum and set the new hostid/mac
> >
> > with mkpl).
> >
> > Then you can disable the diag-switch? parameter and reset the system -
> >
> > the POST should be much, much shorter with a valid NVRAM and
> >
> > diag-switch? set to false.
> >
> > You should then be able to carefully put everything back and restart.
> >
> > Depending if you're more worried about the power-supply not liking
> >
> > many power-cycles or some piece of hardware having a fault, you'll
> >
> > have to choose between 'put everything at once and hope for the best'
> >
> > and 'put things one by one and check every time'...
> >
> > Cordially,
> >
> > --
> >
> > Romain Dolbeau
> >
> > rescue list - http://www.sunhelp.org/mailman/listinfo/rescue
>
> rescue list - http://www.sunhelp.org/mailman/listinfo/rescue