[comp.sys.nsc.32k] It lives

cruff@ncar.ucar.edu (Craig Ruff) (10/14/90)

Doctor, it talked!

Yes, Igor, we are nearly there!

Doctor, it stopped talking. :-(

Alas, Igor, I don't think we have room in the freezer to keep it alive.

And now, for reality:

	The monitor runs fine when the board is cold.  Eventually
	it stops responding.  When reset, it prints the banner up
	to the point where it says, "ram free above 0x1" and dies.
	At this point, it is very repeatable, it behaves the same
	way.  I'll have to spend some time with the scope tomorrow.

	Any hints (other than check all solder joints and IC seating)?
-- 
Craig Ruff      	NCAR			cruff@ncar.ucar.edu
(303) 497-1211  	P.O. Box 3000
			Boulder, CO  80307

george@wombat.bungi.COM (George Scolaro) (10/14/90)

[In the message entitled "It lives (while cold anyway)" on Oct 13, 20:59, Craig Ruff writes:]
> 
> And now, for reality:
> 
> 	The monitor runs fine when the board is cold.  Eventually
> 	it stops responding.  When reset, it prints the banner up
> 	to the point where it says, "ram free above 0x1" and dies.
> 	At this point, it is very repeatable, it behaves the same
> 	way.  I'll have to spend some time with the scope tomorrow.
> 
> 	Any hints (other than check all solder joints and IC seating)?


A can of freeze (that nasty stuff that destroys the ozone), can be a
godsend at this stage. Let the board warm up until it fails and then
carefully cool each section of the board (gently so the freeze doesn't
'splash'). Work your way down to the faulty component/connection.

best regards,

-- 
George Scolaro
george@wombat.bungi.com                [37 20 51 N / 122 03 07 W]

bdale@col.hp.com (Bdale Garbee) (10/16/90)

> 	Any hints (other than check all solder joints and IC seating)?

Almost guaranteed to be a cold solder joint... take a soldering iron and just
walk the whole board, reheating all of the joints until they flow and stop
bubbling... that is the leading cause of temperature dependencies in things
I've built or helped build...

Bdale