how to test transistor?

with a voltmeter..you can find one on ebay for about 3 dlls

An ohmmeter will tell you if it is shorted or opened internally. You cannot go much beyond that without special test equipment and a lot of money.

If you suspect it is damaged, best to toss it and use a new one.

If it's in a circuit, you can use that to test it. Measure the DC voltages on each of the 3 leads and with the schematic, decide if those are correct or not. You can also test it functionally by measuring the AC voltages while it is operating. But those depend on how it is being used. If it is part of a broken complicated feedback circuit, it is sometimes difficult to determine which component is faulty.

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relies upon on if its a pnp or npn or mosfet. in case you have a mutimeter verify for shorts, yet ideal wager is to have the specs for the transistor. sometimes ideal to verify under a load in case you haven't any longer have been given a tester.

From Yahoo!® Answers

"How to check terminals of a transistor?" a good
The following YouTube video demonstrates how to check a transistor.
http://www.youtube.com/watch?v=YsJXFLnA62s&feature=related

"What does HFE mean on my multimeter i know all the rest?" Chris Mclachlan
hFE is the small signal "Forward Current Gain" of a bipolar junction transistor.
YouTube video demonstrates how to find gain of transistor using a multimeter.
http://www.youtube.com/watch?v=fttLJMZuqqo

"What is hFE and what's the function and use of it in multimeter?" mohammad
HFE is an abbreviation, and it stands for "Hybrid parameter forward current gain, common emitter", and is a measure of the DC gain of a junction transistor.
So on the multimeter, it indicates a mode where the meter can measure (probably crudely) HFE of a transistor.