[rescue] Help with Sun 3's

[Daniel Salive]

Hey guys!  New here.  Recently acquired a few sun 3's (mostly 3/60's, but some
3/50's and a 3/110) and can't get any of them to boot.

I've tried both with a monitor and with a serial terminal using a 25 pin to 9
pin  null modem cable and then a 9 to 25 adapter so I had 25 on both ends.
I have many to pick from, and most of them were known to be working when taken
out of service, though that was likely 20 years ago.  I've opened them up and
looked inside and the majority of them have no obvious internal problems.

I have never used a sun 3 before, and rarely used other UNIX stuff, so all
this is new to me.

Most of them have all the red LED lights light up on the back, though a few
only light up 3 (which 3 I forget, though I can look into it more when I try
again).  But no output to either the monitor or the serial terminal.

I waited a long time to see if systems would come up, but still nothing.

Any ideas what could be wrong here?