On Sun, Feb 23, 2003 at 10:03:22PM -0500, Nathan J. Williams wrote:
> kpneal@pobox.com writes:
> 
> > My box has a 400 watt PS. I assume this is a normal ATX power
> > supply, correct? It does have a small cable coming out of the PS
> > that appears to loop back somehow (I didn't unhook it from itself
> > so I'm not 100% sure).
> 
> This is probably the hack-around to the fact that the 164 boards don't
> support ATX soft-power, so something needs to tell the power supply to
> get started.

The cable is made up of a green and a black wire. I notice the
ATX connector on the motherboard only has a single green (#14).
When I measure the voltage across #14 (green) and the nearby #16
(black) I get 5.02v. 
 
> > We were hit with large power droops today because it was windy. Generally
> > when this machine is hit with power sags it shuts off and has to be
> > manually turned back on. Today I can't get it back on. Power cycles
> > don't work. Unplugging it for a few minutes and then plugging it in
> > doesn't work. Leaving the power switch on, unplugging, waiting,
> > turning the switch off, and then plugging it in doesn't work. 
> 
> What level is it failing at? Does the fan in the power supply spin up,
> for example? I wouldn't be too suprised if the power condition
> eventually killed the supply.

% throw switch

Nothing happens.

%

(Really, the fan in the power supply doesn't appear to budge in
the slightest. Nothing else happens besides a lightbulb plugged
into the same power strip dimming for a brief instant.)

 
> > Is there anything special to the 164LX? Might there be a fuse in
> > the power supply (I'm a little hesitant to take the PS apart since
> > it does have capacitors that might be nasty)?
> 
> There probably is a fuse inside the supply, but if it's blown, you
> really just want to replace the supply.

Thought so. Since I'm shopping for a power supply now, I'm wondering
if anyone has any thoughts on PC Power and Cooling? Specifically,
is it really worth it to pay $169 for a 400-425 watt PS? There's a
store across town wanting $60 for the PS they have on their shelf.
My ISP wants $70-$104 for 400-430W: http://www.intrex.com/parts/CasPower.asp
Is Enermax decent or even excellent? PCP+C says they have excellent
protection against power surges and sags, and that sounds pretty
nice right about now. Then again, PCP+C is expensive. 

Man, I don't know squat about power supply vendors. 
 
> I think the only special thing about the power to the 164LX is the
> lack of soft power support. If you have a voltmeter handly, you could
> check if pin 9 is producing the 5v it should always be producing when
> the power cord is in and any physical switch on the supply is turned
> on. You might also try jostling the loopback cable, which should be
> going from PWR-OK, pin 8, to any of the ground pins.

Funky. From #8 (grey) to a black I'm getting 0.02v even if the
machine is unplugged from the wall. If I yank the probes the
voltage drops to 0.00. 

From #9 (purple) to black I'm getting 5.09v with the power switch
on or off. If I yank the power cord the voltage drops to 0.00 over
2-3 seconds. Plug back in and it takes about the same amount of time
to reach 5.09v again.

The few other pins I checked gave either 0.00 or 0.02v. 

(Incidentally, the power connector is labeled on the top of the
connector, so I didn't have to unplug it from the motherboard. I
hope the numbering is correct. I've been giving colors in case
it isn't.)

Thanks again for helping!
-- 
Kevin P. Neal                                http://www.pobox.com/~kpn/
           On the community of supercomputer fans:
"But what we lack in size we make up for in eccentricity." 
  from Steve Gombosi, comp.sys.super, 31 Jul 2000 11:22:43 -0600