how can know this ic is short or leckage LM317 T

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newone

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


I THINK YHIS IS REQULATOR IC IN MOST DIGITAL SATELLITE RECIEVER
 

kubeek

Joined Sep 20, 2005
5,724
Originally posted by newone@Dec 24 2005, 09:25 PM
how can know this ic is short or leckage LM317 T
I THINK YHIS IS REQULATOR IC IN MOST DIGITAL SATELLITE RECIEVER
[post=12662]Quoted post[/post]​
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.
 

mozikluv

Joined Jan 22, 2004
1,437
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
 
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