[rescue] Did i nuke my SS20?

[Kurt Nowak]

I replaced my NVRAMs in my 3 Sun4m's back in April of 2020 (SS20, SS10 and
SS5). All three run Solaris 8 and I had no problems reprogramming them.
They come up fine in POST and they all keep their time.
Mouser #: 511-M48T0810PC1
<https://www.mouser.com/ProductDetail/511-M48T0810PC1>
Mfr. #: *M48T08-100PC1*
Desc.:
*Real Time Clock Real Time Clock 64K (8Kx8) 100ns*

On Mon, Aug 2, 2021 at 11:44 AM Jonathan Chapman <lists at glitchwrks.com>
wrote:

> 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  Original Message b 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 > a timing issue. I have bought a fair number over the last few years
> from > 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 > > 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 -
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