19 Feb
2013
19 Feb
'13
11:49 p.m.
On 2/19/2013 6:32 AM, Jules Richardson wrote:
On 02/18/2013 09:45 PM, mc68010 wrote:
Well battery is fine. It actually took all day to get up to full voltage
On 2/18/2013 7:27 PM, mc68010 wrote:
Hmm. I doubt that +12 is used for much on the PCBs - probably the
serial line drivers but not a lot else. The big +12V draw is probably
the hard drive(s).
I can't remember for sure where the console plugs into now, but I
think it's the main PCB which contains the CPU (was it called PMC in
NCR-speak?) - in which case, maybe see what happens if you disconnect
the power to the hard disk(s) and pull all of the boards except the
main one and the memory; I expect that the machine should be able to
do something with that minimum configuration. The power supply does show some activity when
plugged in. It puts out
+6.75v to the battery and the +5v test point is up. None of the other
test points show anything. There is a switch on the PS for battery
backup
power to ram. In the on position the PS fan spins but, I don't see any
other test points coming up. The +5 is getting to the power switch and
the switch is working fine.
I just went and checked because that was all from memory and it is
actual
+12 getting to the power switch. The +5 test point comes up when the
battery ram backup is turned on which makes sense. When I turn the
power
switch on the +12 at the switch drops to zero. from dead but, it seems fine now. Just for fun I
checked the power
switch with the AC plug in and out.Power switch being a small
circuit
board in the front of the machine that I haven't found a direct
connection to the PS from yet It has +12vdc at one throw with plug in.
With the AC plug out it has +5vdc on the same throw. Obviously coming
off the battery. What that means I don't know.
When I first got it I did try it with the drives and multibus boards
unplugged and it still didn't turn on.
It uses a DB15 for the console port which is odd. I assumed it was just
a serial port. Do they turn on without that console cable installed ?