[rescue] Did i nuke my SS20?

[Jonathan Chapman]

Where did the replacement NVRAM come from? Some of the stuff coming out of
China is completely wrong modules walnut blasted or blacktopped and relabeled.
If it was getting hot and definitely not in backwards, there's a good chance
you got a fake.

Try going down to a really minimal configuration. I've had systems with a lot
of RAM "feel" like they were bricked due to the RAM tests taking so incredibly
long with a dead NVRAM.

FYI, brand-new M48T08s from e.g. Mouser, Digi-Key, etc. don't work in old Suns
anyway, there's some slight difference between the original design and the
stuff you can get now. I've heard it's timing differences, but it affects the
clock section only. That's why I did the GW-48T02-1 and GW-48T08-1 initially,
since I had a pile of NVRAMs to rebuild.

We're working on a complete drop-in replacement for the M48T02 and M48T08 that
doesn't require rebuilding, since trying to buy dead modules from China
resulted in $200 worth of totally counterfeit chips -- not just dead
batteries, which I was fully expecting, but they weren't even the right
modules. Most were Dallas DS12887s as used for PC CMOS.

Thanks,
Jonathan

bbbbbbb Original Message bbbbbbb

On Monday, August 2nd, 2021 at 09:37, Ray Brooks <ray.userinterface at gmail.com>
wrote:

> Hi all,
>
> A sad email. I replaced the NVRAM in my SS20 with an M48T18-150PC1. No
>
> pops, strange noises etc but the new NVRAM chip was getting hot it wouldn't
>
> POST. I switched back to the original NVRAM (stock) chip, still no POST at
>
> all, either via 13W3 or serial cable. My 13W3->VGA adapter tells me I have
>
> no video signal. I was certain I had used the correct NVRAM replacement and
>
> got the correct orientation. I've not seen a Sun in this situation before
>
> and I'm worried that I may have done something wrong and nuked the
>
> motherboard. Can anyone offer any advice as to next steps, or to help me
>
> identify the issue?
>
> Thanks and best regards,
>
> Ray Brooks
>
> rescue list - http://www.sunhelp.org/mailman/listinfo/rescue