That could certainly be the answer, but why would you expect one
of their technicians, in their little technical services/support cubical
to know what's out on the floor? Of course the OP may have been
talking to a clerk manning the service and support desk, and not a
technician at all. But I guess that could be what you meant.
CUSA doesn't sell proprietary PSU, it had to be a mATX or
PS3 size. If the supposed technician doesn't even know
whether CUSA sells these, then one wonders why they are at
CUSA at all, and the correct answer would have been "I don't
know, PSU are in isle 3, you want a (insert form factor
here) PSU".
It's been quite a long time since buying a "replacement" PSU
for under $50, back in the 150w PSU days, at least. Perhaps
this is what explains all your "heat related problems/worries"?
Using $25 PSUs could cause all kinds of problems.
Luck;
Ken
Remember we're talking about an eMachine, not an enthusiast
class system with lots of bells and whistles.
Any *typical* lower-to-mid range OEM system can run fine
from a $35 name brand PSU of the correct ATX(n.n) era.
However, there are plenty of junk generic PSU which would be
a bad choice and these days, some of them prettied up to
look good and sell for more $, but not suitable merely
because they were overrated and poor quality in general.
We can say this because the most power is demanded from the
12V rail and with CPUs now at 150W and less, and ~ 93% or so
motherboard subcircuit efficiency, that's about 13A being
generous (most CPU are not 150W). Add a couple amps for a
HDD to spinup (we can assume it doesn't have 5 of them, the
case probably won't even hold more than 2) and that it likey
has integrated video and the total peak power is about 15A.
Regular power usage would be under 10A.
We can concede something atypical with a ton of hard drives
or gaming video cards will need more, but even then these
are standard PSU.
The system, PSU in question was a small form factor unit,
mATX or PS3. Go to Newegg.com and see what they cost...
$50 is too high, they're about 200W *continuous* power,
labeled as 180-250W, sometimes 300W if most of that is on
12V rail. If you paid $50 for these mATX or PS3, it won't
get you a better PSU, except "Maybe" if PC Power & Cooling
makes one with exotic parts, and then I would expect it to
cost a lot more than $50, and not sell at CUSA.
I'm not in favor of putting a ~ 200W in a desktop system
though, feel the power density is too high for continuous
use, particularly the heatsinking and capacitor space
allowances, unless very low power designed hardware. That
seems to be why those eMachine PSU fail so often, but
nevertheless it is the requirement under which a replacement
is selected so it'll fit in the case. It should be noted
that PS3 has the same mounting face, just shorter, so in
some atypical uses a case that didn't need an optical drive
in it could have it removed so there is enough clearance to
put a std. ATX where a PS3 used to be. That can be handy
for turning the newer generations of OEM systems into
fileservers, as they don't really need an optical drive in
some cases if they can boot a USB drive for maintenance,
recovery or backup purposes.