[rescue] Need help with Cisco 3620

[Eric Webb]

Well, problems again.  I was attempting to send an image to this unit via 
xmodem over the console port when trouble struck.  After that operation I 
haven't had any console connectivity with the unit to speak of -- more of the 
serial garbage.  You can see it trying to talk, but it's just garbage.

I've tried several port configurations to no avail... 9600n81 and n82, 2400n81 
and n82, 4800, 19200, etc.  It was previously working at 2400 n81 by some 
strange luck.  I've been tinkering with the DUART_RST jumper again but it 
seems of no benefit.

So then I started looking elsewhere.  Power supply.  Yep, GND, +5, +12, -12 
all good.  Checked the ground pin on the serial port -- yeah, it's connected 
to the chassis and power supply ground no problem.  Checked across TXD and 
GND and get +12V as well.

At this point do we just assume the DUART is bad and just move on with life?  
It seems a shame because I can tell the router is _trying_ to boot, I just 
can't see it.  This _sounds_ like an RS-232 grounding problem, doesn't it?


Eric