In the process of reviving a NeXTStation Mono I've run into another obstacle. After replacing a dead power supply, everything initially worked and I machine ran fine for a couple of hours. But now, after not having turned it on for a some of weeks, it won't power on anymore. I get no response whatsoever when I press power on. The battery, which I bought new, measures 2.8 volts, I suppose thats sufficient. The difference between then and now is that I replaced the hard drive with an scsi2sd. However, disconnecting the scsi2sd makes no difference. So I guess it's most likely either another dead power supply, or there's something wrong with the mainboard. Now I wonder, is there anything I can do to pinpoint the problem?
Update: I discovered that, when I press the power on key, pin 11 (brown wire, activate line) of the power supply connector gets 2.8 volt. However, as I said earlier, the machine does not turn on. Also, when I connect the + of the battery directly to pin 11, nothing happens. Does this mean the power supply is dead, or could the mother board still be the problem?
I believe the battery voltage is too low. On an unloaded battery I show 3.3V. I would get another battery (different vendor) and try again.
Jerry