[rescue] Hanging with NVRAM in?

[Patrick Finnegan]

On Thu, Nov 20, 2025, 07:44 Mouse via rescue <rescue at sunhelp.org> wrote:

> I've got a bunch of SLC and ELC boards, saved from back in the day,
> with a handful of the connector boards they plug into.
>
> I got them out recently because of the "SPARCstation 1 boot woes"
> thread.  I found I had one MK48T02B, which of course had a long-dead
> battery.  So I moved it from machine to machine.  All worked, except of
> course that the dead battery meant it didn't retain anything over a
> power-off.
>
> Yesterday, I found two more ELC boards, so I tried to set them up.
>
> And I saw some very peculiar behaviour.
>
> With the NVRAM socket empty, the boards power up and go through
> selftest just fine - well, as fine as can be expected; they complain
> about the NVRAM not retaining data, but that's no surprise when there
> isn't any NVRAM there.  They even boot diskfully, albeit with a
> 00:00:00:00:00:00 MAC.
>
> But with the NVRAM in the socket?  They don't print any of the selftest
> messages on power-up, not even the first few that they print even with
> no RAM installed.  (I didn't wait long - several seconds - but the
> first messages are normally close enough to instant that at the human
> layer I can't see any delay.)
>
> So I tried the other boards, the ones that worked (with the same
> MK48T02B) before.  Same syndrome.
>
> But pull the chip, and they go back to "working".
>
> Anyone have any idea what might be behind this?
>

A completely dead battery can cause this, along with an otherwise damaged
nvram chip.

Patrick Finnegan

>
>
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