how can know this ic is short or leckage LM317 T

Discussion in 'General Electronics Chat' started by newone, Dec 24, 2005.

  1. newone

    Thread Starter Member

    Dec 23, 2005
    14
    0
    how can know this ic is short or leckage LM317 T


    I THINK YHIS IS REQULATOR IC IN MOST DIGITAL SATELLITE RECIEVER
     
  2. kubeek

    AAC Fanatic!

    Sep 20, 2005
    4,587
    775
    Find schematic (e.g alldatasheet.com). Connect it properly, measure the current it takes. If it is much more than written in the cataloge, it´s bad. Count the voltage it should give (form R1 and R2) and compare with the voltage it really gives. Difference higher than say 0.5V, it´s bad too.
     
  3. gtjr_ph

    New Member

    Dec 25, 2005
    4
    0
    that a adjustible voltage regulator
     
  4. mozikluv

    AAC Fanatic!

    Jan 22, 2004
    1,437
    1
    hi

    if it can't regulate, assuming that all other accesory parts are good, then that adjustable regulator is bad. if the variable resistor connected to the adjust pin is defective, you will have an erratic output. if the regulator gets hot to touch even if the voltage difference of the input to the output is not more than 5v, the device is defective. these are usually the signs of a defective regulator.

    moz
     
  5. Gadget

    Distinguished Member

    Jan 10, 2006
    613
    0
    Also if it get hot with no load.
     
Loading...