I have a NeXT 152.00 Powersupply, it appears it will only power-on if I use the NeXT CRT monitor with it. I am trying to use it with a Soundbox and LCD, but it won't power on.
Is there any way to modify the power supply so it will work? PLEASE HELP =)
found some info:
5.42 How to boot a NeXT without a monitor?
The procedure is to just touch pins 6 and GND on the DB-19 NeXT
monitor out with a 470 Ohm resistor (450 is the actual resistance, but
470 ohms is more commonly found in resistors). Pin 6 is the power
sense, and pins 13-19 (and the DB shell) are the GND. Just say "pin
19", it may be easier.
There's a pinout diagram of the DB-19 in the NeXT Users Reference
Manual.
If you have an old Cube, the power supply needs to have more power
drawn from it than an 030 (and 040?) board uses to stay on. So: On the
DB-19, attach a Power Resistor (20 Ohm, at least 20 Watt) between pins
12 and GND. (Pin 12 is -12V, pin 13 works well for GND). Then just
"touch" the 470 ohm resistor as described above, and you're set. The
20 Ohm resistor draws an old 030 running without monitor in an old
CUBE), but it isn't necessary - just don't touch it (*HOT!* ;-)