There is a possibility the Apple Hardware Test version acquired through download
from that site, may not work in the model iMac G4 computer you have; these had
a newer test included with the computer in their original software packet disc set.
If one were to try & burn a .DMG file to a CD, you may have to see about using
the computer's version of Disk Utility since it can handle disk images and burns.
A test of the process would require a few extra blank media discs, since there is
a chance the first one(s) may not correctly record an expanded image on them.
In some instances, a .dmg could be burned to the CD media as-is, unopened.
I suspect you would need to get a set of original Apple software restore/install
disc software like that specific computer model shipped with, to get the A.H.T.
On startup, there usually is a hardware self-test, to a limited degree, in OS X.
Not sure how one would force-initiate the process from Terminal, or after a
Single User mode start-up. Using Terminal or its equivalent can be tedious &
requires some understanding of rules and processes in order to use it right.
What kind of hardware problems does the iMac G4 1.0GHz 17" LCD machine have?
{In MacTracker app, sometimes you can see where more than one version Mac
of a similar build year shows an Apple Hardware Test version number as being
the correct version for more than one model, in example, eMac and iMac G4 of
a certain year may appear to use the same AHT version. But they may need to
be on the model-specific original disc, in order to be used in each of those Macs.}
MacTracker has some Mac specs and can be helpful as a reference; as are some
online resources such as everymac.com's site. You download the former from their
site:
http://mactracker.ca and it goes into the Apps folder, a link can be dragged in
to the Dock for easier access. Or an alias could be put into a folder of aliases for
those items not wanted in the Dock, so Apps folder would not need be open to run.
Upon referencing the copy of MacTracker I have in my computer here, I see there
is no second machine use of this iMac G4 1.0GHz Apple Hardware Test; and in
the build series of this specific iMac you state you have, there is one of three AHT
versions it may have shipped with, depending on the hardware configured in it:
AHT (iMac) 2.0, 2.0.1, 2.0.2
There may be some third party professional hardware test an expert may have in
their catalog of repair tools, or a pro set of such AHT versions a trained expert
would have invested in as part of their Apple training kit; so if you find qualified
help who has experience in these older G4 iMac models, maybe they could test it.
What does the computer do, that leads you to want or need to test the hardware?
Hopefully if it does need some hardware (maybe replacement hard disk drive, etc)
that's about it. The 'take apart' information pages available online cover some of it.
Good luck & happy computing! 🙂