1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

Yamaha keyboard does not power up

Discussion in 'Repairing Electronics' started by stoocats, Apr 22, 2010.

  1. stoocats

    stoocats New Member

    Joined:
    Apr 22, 2010
    Messages:
    2
    Likes:
    0
    Location:
    Canada
    Neither adaptor nor batteries will power up my keyboard. I suspect a TO-220 package 3 lead transistor.its labeled BI342 but cannot find this anywhere.Any ideas where to troubleshoot?

    tks
     
  2. HiTech

    HiTech Well-Known Member

    Joined:
    Jun 28, 2006
    Messages:
    2,874
    Likes:
    30
    Location:
    Penna. USA
    It's probably a 2SB1342 bot a BI342 often the prefix is ommitted and that I is likely a 1. The 2SB1342 is a TO-220 pkg. and it's specs are here:
    2SB1342 Datasheet

    What makes you think it's the culprit? Is it obvious by looking at it?
     
  3. stoocats

    stoocats New Member

    Joined:
    Apr 22, 2010
    Messages:
    2
    Likes:
    0
    Location:
    Canada
    The power supply is a 12V adapter... the circuit board where the power enters, has several caps, resistors, and this transistor together with a smaller one. When I hold the power button on for a while this transistor warms up. The only thing that happens is a barely audible thump through the speakers. The LCD on the keyboard doesn`t get any juice.
     
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. HiTech

    HiTech Well-Known Member

    Joined:
    Jun 28, 2006
    Messages:
    2,874
    Likes:
    30
    Location:
    Penna. USA

    is the LCD display backlit? or is it completely out without even segments? can you measure voltage on other board locations that may have marked voltages on it? If so the power supply isn't the issue. Often board connectors will be labeled as to each pin's function. Look for 12 volts and or 5 volts dc. for starters.
     

Share This Page