on A1 WX the transformer have one primary coil and 3 secondary coil "mutiple voltage"
is not easy to change it !!

This adapter from maplin is impulse one (that's why it is so small). When you plug MSX into adapter it senses shortage and does protective shutdown.

In order to connect your MSX you will need conventional "big-transformer-based" adapter.

In order to prove or disprove my proposition you will need a multimeter (voltmeter) to see what happens on adapter's output when you turn MSX on.

hi good news. i replaced the transformer for another one and msx now works perfectly. one more question. i notice the transformer outputs 110v whereas the msx needs 100v. will this extra 10v kill the system? regards

No, in general it will increase the 'safety margin' of a power supply (the ability to handles power surges / short interruptions), and old equipment can use that since other parts of the supply may degenerate. If it's a switching supply, this comes at no cost, if it's a linear one, it comes at the cost of a bit more heat / reduced efficiency. Don't worry about it unless parts get *really* hot.

All step down converters you find in the UK high street shops are usually for using US appliances in the UK, so they are stepping down to 110V (115/120 or whatever they use in the US).

Although people usually say that 110V is within the tolerance, if you want a transformer specifically for using Japanese appliances, it might be best to get one that outputs 100V.
Link to a transformer site (I bought mine from here for high power rating one for my PS3, as it is hard to find ones rated over 300W) :
www.airlinktransformers.com/japanese-transformers.asp