how can i recognize the malmsteen signature guitar that i wanna to buy is original?

Buying from a Fender dealer is a good start but if your buying online you need to check the reputation of your source and be familiar with what the guitar looks like up close.

Serial number is really important get as you can see if it has been mentioned as stolen or counterfeit on the web.
consumerrelations@fender.com can help confirm the specs of the guitar if you email them the serial.

Be sure with the seller that the guitar your interested in is free from modifications or defects as this can make a big difference in price.

Also be wary of something that looks like a real bargain or has no real accurate description or poor photos. Sellers sometimes do this to make it harder for the buyer to make an assessment prior to purchase.

Sellers that take detailed shots of every aspect of the guitar including electronics and neck and body cavities will give you better idea.

Keep in mind even if you pay the going rate your better in the long run getting exactly what you pay for rather than something that is a bargain but for a reason.

Do some research on what what a real Malmsteen Strat should look like if you are not buying a new one from an authorized dealer. Check out pics of some Malmsteen Strats online or for sale: http://www.google.com/images?hl=en&q=yn ... a=N&tab=wi and http://www.google.com/products?hl=en&q= ... a=N&tab=wf Print out some of these pics. Pay attention to the details like decals, hardware, neckplate, etc. If the one you are thinking of buying doesn't match the ones you see in the links above, then don't buy it.

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Obligatory gear list: Fender, Rickenbacker, Gibson, Gretsch, Vox, Martin, and more Fender.