Yep, I have it in backwards. I'll re-solder it later tonight or Wednesday. Thanks! -- James. -----Original Message----- From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of Jinx Sent: Sunday, May 18, 2008 19:39 To: Microcontroller discussion list - Public. Subject: Re: [EE] Parallel Port nSelect pin relay driver > Err... on a TO-92 case, the base is the middle one, right? Not always, but generally. Although if you're used to working with particular parts it may be that those *do not* have b in the middle, so then "generally" would not be true > How do you know which is the emitter and which is the collector? You could check against this http://www.fairchildsemi.com/ds/2N/2N3904.pdf As an established industry part, what you have probably conforms Double-check http://users.otenet.gr/~ATHSAM/theory/Transistor_test_type_and_polarity_eng. htm Maybe your multimeter has a transistor tester built in ? -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist