caller said:
my brother's power supply (300W) went on his desktop.
We bought a new dynex 350W power supply, installed it, carefully
checked connections, turned on and power stayed on for couple of
seconds then stopped. Reseated all connections, tried again, no luck.
When we flip the voltage switch from 115 to 230 on the power supply,
the computer powers up. We are in the US
Is this normal? or do we have another issue somewhere else possibly.
I don't want to burn out his computer on 230v. Will he harm the
computer running at 230v and not 115?
I've been searching online for a while and can't find any insight.
Thanks for your response.
Patty
Dynex has a contact page here. You could ask them.
http://www.dynexproducts.com/t-contact.aspx
The back of a downloadable Dynex manuals says:
www.dynexproducts.com (800) 305-2204
Distributed by Best Buy Purchasing, LLC
7601 Penn Ave. South, Richfield, MN 55423 U.S.A.
so they appear to be a store brand of Best Buy.
It could be that the switch was installed backwards. Either
all the units are like that, or your unit is different than
all the rest. Maybe the support person can check what a
known good unit looks like for you.
The biggest danger, as far as I know, is being in a 230V country
and accidentally selecting 115V. That likely blows the big input
cap or rectifiers, leading to the fuse blowing (accompanied by
a loud bang no doubt). In a 115V country, the consequences might
be a bit tamer. If the switch was in the 230V position, presumably
the primary side gets less than the normal voltage, and the input
current would have to be bumped up to compensate. I believe I've
read of such a misconfigured supply, being "weak" and not delivering
properly if heavily loaded.
If you want to see what that switch might be doing, this nice
reference schematic for an ATX supply, gives you some idea as
to what is inside. This schematic is from an older unit, so
design techniques may have changed since this was done - but
at least the primary side, should have remained the same
over the years. The switch is to the right of the "Input Filter"
section of the schematic. In the 115V position, the switch closes
a circuit. In the 230V position, the switch remains open. Overall
protection for this supply, is via fuse F1 on the "L" line
terminal.
http://www.pavouk.org/hw/en_atxps.html
Opening your supply will void the warranty, just in case you
were thinking of having a look. The tamper-proofing sticker is
one way they might catch you.
Paul
