This might have been mentioned before, I'm not sure. Having bought voltage regulators from china that where fake, i don't bother with that anymore. I've got a trusted handful of ebay sellers that have NOS new old stock. But i thought I'd try a seller with some transistors that where home based here in the UK. They arrived today and check out fine doing a test with the diode function, but there not looking like the normal finish to me. The tab is more shiny, i filed off a little of the plating, sure enough its copper. But they just seem not quite right. I don't have a camera handy at the moment, but will put up a comparison later between legit transistor, and the one's I'm unsure about. I'm tempted to do a distructive test, but something is telling me to bread board one and test it under load.
I knew i might be buying fake, but at £1.00 each it was worth a gamble. The devices are TIP36C power transistors. I was hoping to get a bargain by buying a small quantity first. Then a few more if they checked out good. The voltage regulators from china where lm317k's i opened a fake one and could see the difference immediately, they couldn't even handle 500mA of current. Anyone else been stung with fake transistors. Thoughts appreciated.