[BillyWhiz]

Hi Y'all,

I have found a short circuit on the component L2 but I don't know what it is? it looks like a diode..

Kind Regards,
Billy

 

[Delta Prime]

L2 on a PCB silk screened and written on schematic's refers to a component that has inductance, whose value would be in Henry's. That's the fancy way to describe a coil . By the way you see L1 there's nothing there no coil no inductor. For DC inductors will show up as a short circuit this is normal there is a DC resistance to the coil but as you discovered the resistance is so small your meter thinks it's a short circuit. What you must do is get a LCR meter and measure it's inductance.
So unfortunately this component
Would check okay to me if I was troubleshooting and I would move on something else is wrong.
I misspoke un-solder one lead of L1 that inductor and check again

 

[BillyWhiz]

Hi Delta Prime,
Thank you for your reply, I checked L2 with my meter and it comes up as a resistor with 0.04 ohm, also There was a inductor with 1.53mH in L1 which looks like a resistor!

 

[Delta Prime]

Okay just for kicks and giggles un-solder one leg and retest please .

 

[BillyWhiz]

I took the components out to test them already.

 

[Delta Prime]

Well put them back! Just kidding what seems to be the problem you are having is it visually L2 looks like a diode and L1 looks like a resistor photos please

 

[Delta Prime]

I checked L2 with my meter and it comes up as a resistor with 0.04 ohm, also There was a inductor with 1.53mH in L1 which looks like a resistor!

Then L2 should have an inductance along with it as wel and vice versa what is the DC resistance of L1

 

[BillyWhiz]

The top (Black) has come from L2 and reads as a resistor, and the bottom which looks like a resistor is the one that reads as an inductor?

 

[Delta Prime]

Show me your instrumentation you're taking these readings with

 

[BillyWhiz]

please see attached

 

[Delta Prime]

Inductors have color codes associated with them like resistors
Use this as reference only

 

[Delta Prime]

You're multifunction tester tc1
Apparently this is your inductance meter

 

[BillyWhiz]

Confusing why this reads as a resistor when its completely black?

 

[Delta Prime]

Stay with me... concentrate... pay attention... we can find out right now inductors add when put or connected in series
Just like resistors they add as well when put in series. Therefore we already know the inductance of L1 add L2 in series with L1 measure the total inductance.

 

[Delta Prime]

While you're making those measurements. I just realized I sound just like my old professor.

 

[BillyWhiz]

Okay here we go....

 

[BillyWhiz]

You sound like my new professor

 

[Delta Prime]

Well then let this be a lesson to you I got to go to bed... sorry buddy someone will be a long shortly. Good night.

 

[BillyWhiz]

okay thanks and enjoy your sleep...

 

[kellys_eye]

It's not really an inductor - it's a ferrite suppressor, just a piece of wire passing through the core of a piece of ferrite. OK, that's 'really' an inductor but the value will be smaaaaallllllll. Either way it reads short-circuit normally and your circuit will likely work even if you remove it and replace it with a short length of wire (but I wouldn't do that).

Very, very unlikely it's dud. What is the issue that made you suspect it in the first place?