Just retired and I'm trying to get into electronics, particularly repairing broken keyboards and I've come up against a bit of a show stopper. I've done several online courses on transistors but while I understand PNP and NPN pretty well what I don't understand is why, if there are only 2 types, there are so many different units - 1,000s of them apparently - and why it is so hard to find replacements even when the ID numbering is clear.
So my question is, given you have a number (in my case D1028 BK411), why can't I find a replacement and, more generally, why can't I substitute a universal type replacement?
I have the same problem with surface mounted capacitors but I'll save that for another thread. Generally, I am finding it all very frustrating. Electronics is all about precision but when it comes to identifying bits and pieces that seems to go out the window.)
So my question is, given you have a number (in my case D1028 BK411), why can't I find a replacement and, more generally, why can't I substitute a universal type replacement?
I have the same problem with surface mounted capacitors but I'll save that for another thread. Generally, I am finding it all very frustrating. Electronics is all about precision but when it comes to identifying bits and pieces that seems to go out the window.)