I should make clear that for what I'm saying below, I was NOT testing supplies on their own, but was indeed testing a complete cube with the logic and hard drives hooked up- just with no MegaPixel display attached.
And the point stands- Without a reasonable dummy load for the display itself, some cubes wouldn't stay on. This was about 12 years ago and I was in middle school so I didn't take notes like I do now. Ergo I don't recall more specifics. Just that I used two sizable ceramic resistors that hung off the display connector to mitigate this behavior. Sent from my iPhone > On Oct 25, 2015, at 17:42, Ian Finder <ian.fin...@gmail.com> wrote: > > No- if it works with the standard display, the supply is fine. > > Now that that's clear, I recall some cube supplies would do this without a > load for a display- I used to test them by triggering the power-on pin, and > seem to remember this behavior occurring if I didn't have a big-ass resistor > attached across the pins that normally supplied power to the CRT. > > Try getting a dummy load on there, the circuitry you have may not be putting > enough load on the lines that usually run the CRT to keep the supply in a > steady state. > > Cheers, > > - Ian > > Sent from my iPhone > >>> On Oct 25, 2015, at 16:37, Toby Thain <t...@telegraphics.com.au> wrote: >>> >>> On 2015-10-25 7:21 PM, Ian Finder wrote: >>> I would replace the electrolytic capacitors in the power supply before >>> going further. >> >> Well, the problem disappears with the standard setup. You still think caps >> could be at issue with the splitter setup? What's your detailed thinking? >> >> --Toby >> >>> Sent from my iPhone >>> >>>>> On Oct 25, 2015, at 15:38, Toby Thain <t...@telegraphics.com.au> wrote: >>>>> >>>>> On 2015-10-25 5:28 PM, Toby Thain wrote: >>>>> Hi, >>>>> >>>>> After a few years I wanted to try my Cube with the soundbox/VGA splitter >>>>> configuration for the first time. (I have the fading phosphor N4000A so >>>>> have been keen to have an alternate video solution.) >>>>> >>>>> However, all is not well. Using the keyboard power button, the machine >>>>> powers on for a couple of seconds, just long enough to see a NeXT logo >>>>> and grey desktop on the VGA (yay!) but then powers itself off again. >>>> >>>> >>>> I did the obvious thing and tested it with a standard monitor and cable >>>> and everything is okay. So the problem must exist with the >>>> splitter/soundbox setup. Soft power signals? >>>> >>>> Any suggestions welcome. >>>> >>>> --Toby >>>> >>>>> Any clues? >>>>> >>>>> Thanks in advance >>>>> >>>>> --Toby >>>>> (not having a good classic computing week) >>
