how to identify components?

[sparkotronic]

Hi, How do you go about identifying circuit components? I'm looking to repair some drive boards in work and I need to identify one of the Mosfet transistors. When I phone RS or Farnell they say that they can's supply it and are unable to find an alternative. Googling it doesn't help either. The only markings on it are K1525? Any help would be most appreciated Regards, Colin

[panic mode]

Hi Colin, Picture of the component would help but I guess chances are you are looking into 2SK1525. (does it look like this: http://english.electronica-pt.com/db/cross...php?ref=2SK1525) Btw. This is so called Japaneese component marking where everything starts with 1S (for diodes) and 2S (transistors) etc. For transistor there is additional letter and 3-4 digit number (in this case K1525). because the first two characters are "obvious", they are often left out and when looking for datasheet, you need to add them up. for example 2SC1737 is NPN signal transistor which is marked only C1737 btw. USA uses 1N (diodes) and 2N (transistors) followed by number. European marking is a bit more complicated with first letter indicating material: A - Germanium B - Silicon second letter specifies function A - general purpose diode B - varactor diode (varicap) C -low frequency transitor D - low freq. power transistor F - high freq. transistor L - power transtor U - switching transitor (power) etc. then there is Russian method as well (i did not do much with electronics in over 20 years so I don't quite recall details on Russian marking... I think K was for Silicon etc.).