What adapter are you using?

It should be 24V/100mA Center Positive (2.1mm barrel plug).

If you can find one in Australia that meets that description –
you won’t need the step-down transformer.

Analogman carries these: http://www.buyanalogman.com/product_p/eh 24dc-100.htm

I’m using an old ehx (graphic eq) with attatched cord with a stepdown transformer in the UK with no problems, so I don’t think that would be an issue, in theory it’s no different from plugging it in to a US wall outlet.

I’m using one of these.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=130279823913

…so my guess would be that something has got damaged in the post, if it’s an old unit it’s quite possible that a wire has come unsoldered or something like that, it might be best to take some photo’s on the insides and post them here and see if anyone can spot anything….you might even notice a wire off somewhere yourself.

For what it’s worth: I moved from the US to Switzerland recently & brought along 10
Step Down Converters. Four of them did not work properly. 2 did nothing
& 2 made strange noises.

It’s possible (although I couldn’t say for sure) that the one you have is damaged.