🚀 go-pugleaf

thank you for your help! the problem is solved with your help and the 
computer is running again. 

the received answers to my problem 'computer doesn't start again when
i press the power key' mentioned three possible causes:

1) the power supply is dead
2) the battery is dead or has bad contact
3) damaged data in non-volatile ram buffered by the battery

as the total opposite of a hardware freak i am not able to check 1) so
i tried first to check 2) the proper operation of the battery. Pasi 
'Albert' Ojala <po87553@cs.tut.fi> suggested to measure the voltage of
the battery between the shield of the ethernet tube (ground) and pin 6
of the monitor outlet (without power cord connected). there were the
correct 2.5 V or more - the battery was ok! now i performed the final
check 3^) i opened the next (oh so many nice little pieces!) and re-
moved the battery for about 30s then i inserted it again (check the
proper direction!). several answers said that this would destroy the 
eventually bad data buffered in the non-volatile ram. the answers said 
that doing this does destroy correct data (boot parameters, hardware 
password) too. after assembling the computer together again (service 
friendly - one screw!) i pressed the power key... ... ... WHOW the
computer is starting!!! it tried first to check for ethernet to boot
from - ok this was caused by the default boot parameters and could
be fixed by setting the correct boot device according to the sysadmin
manual...


thank you very much!
      stefan

--

##############################################################################
Institut fuer Neue Materialien (INM) #  
Universitaet des Saarlandes, Geb. 43 # Phone: +49 681 302 5086
Stefan Brueck                        # E-Mail (Internet): brueck@inm.uni-sb.de
W-6600 Saarbruecken (Germany)        #
##############################################################################

This is a forwarded message from: Juha Tuominen

>as the total opposite of a hardware freak i am not able to check 1) so
>i tried first to check 2) the proper operation of the battery. Pasi 
>'Albert' Ojala <po87553@cs.tut.fi> suggested to measure the voltage of
>the battery between the shield of the ethernet tube (ground) and pin 6
>of the monitor outlet (without power cord connected). there were the
>correct 2.5 V or more - the battery was ok! now i performed the final

To be honest, I made a mistake. If your NeXT doesn't boot, check the
voltage between system ground and pin 6 on the monitor D connector. 
Ethernet ground tube IS NOT CONNECTED to the system digital ground - directly.
If you look your NeXT cpu board in front of a light, you can see that the
power and ground layers inside the board are cut around the ethernet stuff.
That's because ethernet wires are often connected and disconnected when system
is up and running. The potential differences between the NeXT and etherenet
shield (and hot wire, too) may otherwise damage the cpu board. That's why
ethernet stuff is separated of the other system and signals and
ground is connected to it via a converter. (A blue little tube, made by SONY,
about 10 cm from the ethernet connector). OK, the monitor D-connector
pins from 13 to 19 are connected to ground (check Q&A for futher information,
they all work for measurements to find out if the battery is dead or not),
so if you have to check the battery condition, take ground one of those
pins WHEN THE SYSTEM IS NOT ON AND NOT EVEN WIRED TO THE WALL OR THE 
MONITOR!.
-Juha
-- 
Pasi 'Albert' Ojala     The other author of AXsh
po87553@cs.tut.fi	albert@cc.tut.fi