[rescue] Origin 200 - flaky serial console

[Gavin Hubbard]

Hi Lads

I rescued an O200 system today (single 225Mhz, 512MB, 4x9GB). Unfortunately
it has a problem with the serial port (which is why the owner let it go for
150USD and some beer). I figure I can at least recycle the memory and disk
carriers if I can't get it working again.

I attached a <2-3 3-2 5-5> serial cable and the console came up the first
time I booted, but for some reason it won't come up again no matter how
many times I reboot. The serial console and cable work (I connected the
console back to back with another console and they communicate with no
problems).

The Craylink DIP switches are set to master. It has no crosstown module so
a XIO loopback cable isn't required. The DIMMs are firmly seated in the
correct sockets. The system-boards are firmly connected. There are no loose
internal power or data cables. 

There is no junk output. The console simply gives no output at all.

I am going to construct a mini-DIN adaptor so I can connect to the MSC and
check for chassis warning codes, but that will take a few days (RS didn't
have the part I needed in stock).

So - any suggestions? Why would the console work, then stop working?
Answers on the back of a postcard please :-)

Seriously - I'm stumped, please help.

Regards,

Gavin