🚀 go-pugleaf

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