On Thu, 04 Jun 2009 18:05:28 -0500, Ken wrote:

Either you blew something by plugging the ram in while the standby
power was on or the new ram requires more standby power than the power
supply can produce.

This makes the most sense. I am not sure the standby current is listed
for either PS on the label. Each rail is, but not the standby current.

It is on every psu I've looked at, +5Vsb. It's not very high about 1amp
but I did have a motherboard that required 1.5amp minimum.

The power supply comes fully on initially, as another poster explained,
to run the cpu and read the BIOS to see what to do on power
application. Your psu is trying to do this but the initial surge is too
much for it and it shuts down and then has another go. I've seen this
when a drive failed once and once when lightning took out the memory on
a system.

You could try disconnecting the drives to see what happens but check
the 3.3v rail limits on the psu labels between your 250 and 350W psus.
It may just be the 5 and 12 volts that have extra current and the 3.3v
rails have the same limits. The memory uses the 3.3v rails [1] with on
motherboard regulators dropping it to what the memory needs, and it's
possible that the new memory is simply taking too much when when first
switched on. What I'm trying to say is that just because a power supply
is a higher wattage it doesn't necessarily follow that all rails have
the limits increased.

I'd want to run a memory test, such as Memtest86(+) for 24 hours though
to ensure that the memory wasn't damaged by inserting it with the
standby power on. The system gets the settings for the ram from a chip
on the ram module and if that's been damaged the defaults may be a
little high and overheat things after a while causing failures. If you
are running Windows then CPU-Z should be able to read and display the
ram configuration for you.


[1] usually I think, at one time memory was run at 3.3v but nowadays it
seems to be around about 2v and I don't know if that's from the 3.3v
rail or the 5v rail regulated down.

--
Regards - Rodney Pont
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