Re: Ultra 60 NVRAM

[Tobias Ulmer <tobiasu%tmux.org@localhost>]

On Thu, Nov 30, 2017 at 03:06:25PM +0000, Jaap Boender wrote:
> Hi all,
> 
> Not strictly a NetBSD question, but I imagine someone here must know the
> answer to this...
> 
> Trying to revive my Ultra 60 for NetBSD purposes, I found that the NVRAM
> battery had died.
> 
> I ordered a M48T59Y-70PC1 chip to replace it with, but after I changed it
> the machine refuses to boot (even the power LED doesn't come on).
> 
> The new chip is a -70PC1D rather than a -70PC1U. I don't think I've fried
> anything - the machine still boots fine with the old NVRAM chip.

That's just a manufacture revision code. Doesn't matter, something else
is wrong. I would not insert that chip again.

Since you have working, empty timer, take a knife and carefully dig
out the epoxy in the pocket where the battery is connected. I believe
it's the pocket on the "Vss" (ground) pin side, opposite of the pin 1
marking.

Cut the two leads to the dead battery, solder on a new battery holder and
put in any 3V lithium cell you like (I'd recommend something popular
like CR2032). Polarity is easy to check, the negative side of the
battery is connected directly to the Vss pin. Have a look into the datasheet.

And of course it's on youtube...:
https://www.youtube.com/watch?v=wwFM2RuAGno
https://www.youtube.com/watch?v=VV2GHgwrbGU

Once that's done, program the eeprom again:
http://www.menet.umn.edu/~bob/FAQ/sun-nvram-hostid.faq


> 
> So, is the D rather than U significant? Is the chip just defective? Should I
> do something to reset the NVRAM? (I tried Stop-N at boot, but that doesn't
> seem to have any effect)
> 
> any light shed on this appreciated,
> 
>   Jaap