I have an AC/DC power supply (from the UK). It is labelled 230V/50hz. As far as I know, electric in Mainland britain is 240V/50hz. Indeed, the unit did correctly power the Korg keyboard in the UK. The DC output is labelled 21V / 1.2A. (The Korg piano is indeed labelled 21V input on the back.)
Now I have the same power supply in France. As far as I know, France is also 230V/50hz. When I plug the power supply in the wall in france (obviously using a 50 cent plastic plug adaptor - of course NOT using any sort of transformer, etc).
Using a good multimeter, in France the output from the power supply is 26 volts (around 25.9 to 26). Is that normal? Why not just 21?
(Unfortunately I never tested the output, in the UK.) Now, the electric piano is actually not working. ie, I did plug the power supply in question in to the Piano and no result, nothing comes on.
Does anyone know:
Why is it showing 26 rather than 21 as labeled?
Do you reckon I may have blown a fuse in the piano, due to the 26 versus 21? Or, perhaps not a fuse, just permanently ruined it? Conversely, is it likely just some other unrelated problem with the piano?
To rephrase: If the piano says 21V on the back, would 26 V be too hot, or no problem, typically?
It's an expensive pro piano and a real nuisance! It is a mystery that it is showing 26V. It's almost impossible to find a replacement power supply, and, that may well not be the problem.
A further question for you experts: would an alternate supply, eg, http://www.webducommerce.com/alimentation-21v/chargeur-alim-secteur-21v-1-7a-36w-p-3485.html with a HIGHER amperage rating, actually be OK?? Should you try to match the amp rating, or us the point that it must be "at least" 1.2A in my example? Thanks again, pro geniuses!