Re: P4 on sun3/sun3x (Re: NetBSD/sun3 10.0_RC2 problems on sun 3/60)

[Chris Hanson <cmhanson%eschatologist.net@localhost>]

On Jan 14, 2024, at 11:47 PM, Romain Dolbeau <romain%dolbeau.org@localhost> wrote:
> 
> Unfortunately my 3/80 motherboard blew a cap when I tried to power it
> up with my homemade ATX adapter (https://github.com/rdolbeau/SS1_ATX).
> The pinouts of the adapter seem OK to me and I haven't figured out why,
> I presume the cap died of old age...
> Anyway the mobo didn't give any sign of life.on the serai port when i
> tried again, so for now my idea of a P4FPGA to follow up on the
> SBusFPGA is stalled.

There's a specific tantalum capacitor in one corner of the logic board that *always* blows on the 3/80, and the suggestion I received from numerous people after mine blew was to just desolder the remnant and remove it, and not to bother replacing. I believe they said it's just a filter cap that only really matters if you have super-noisy power or something like that.

I've not removed mine yet, but I plan to whenever I get back to playing with my 3/80. Fortunately I was just powering up the bare board when it blew, so I don't have anything to clean up inside the case. Had to let things air out a bit though...

  -- Chris