19 Feb
2013
19 Feb
'13
6:32 a.m.
On 02/18/2013 09:45 PM, mc68010 wrote:
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.
cheers
Jules
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.