Missing negative voltage 2
  • Hi

    I've just started assembling the SMR-4 board for the Shrunthi-1 and I tested the power supplysection.
    the blue point on the far left (near the connector labelled GND) to all blue points are at 0V and to all the red points at 5V as well.
    But to all The green point are at 0V. not -5v.
    so I was searching this forum to find a solution.

    I have found the topic from perplx Nov 23rd 2010. It's almost same problem.

    I think I have correctly inserted the LT1054. At least the round mark is near the IC1 marking on the PCB.
    I tested by a power supply 9v300mA and other power supply 9v,12v which can switch between voltages.

    It would be great, If somebody help me.

  • What is the voltage on pin 5 of the LT1054?

  • I am sorry.
    I am beginner of electronics.

    from GRD to pin 5 of the LT1054 is at 0V.
  • I sort it out!!!
    Thanks to mention about the voltage on pin 5 of the LT1054.

    I checked the other topic

    So I de-soldered C27, C31 and C2 and re-soldered them Properly.
    I get right voltage now.

    Thanx very much