Hello everyone!!

In this instructable I will be telling you how to test your transistors with the help of your multimeters.

Now, forget those circuits used for testing transistors and now its time to get easy and practical.


I had been working on an instructable (http://www.instructables.com/id/HOW-TO-MAKE-DANCING-LEDS/)
And it had been working well. But when I thought to upload its video , it didn't work!

I was really shocked what had happened to it. The resistors were fine and the capacitors too. So, I decided to check my transistor as either of them would not be working.
I got the malfuctioned one replaced and now it works!!!

So,I thought to share this thing with others and I ended  up making this instructable.
I hater4 months ago

Hello prajal12

My receiver Kenwood KR-V127R sound worse than a very small portable player, I suspect the power output transistors are dying will this test confirm that.Thanks

this is a good trick! have you ever found a transistor that did not have the base as the middle pin?

Why yes of course!In my sony str-de425 the transistors mn2488 and mp1620 both have the base as the first and emitter and collector as middle and 3rd it is very confusing. :)

BD 140 and it's similar types have base on 3rd pin

pranjal12 (author)  amandaghassaei2 years ago
No! I have never seen one but if u have it then you can upload a picture of it and I will tell u whether u can test it or not.

I have two RF Power Transistors (out of ham radio transceiver) I am trying to test. I get 710 ohms from Emitter-Collector (but open loop in reverse). Otherwise they test normal. They are very hot in circuit. What is your opinion?

AbdulR136 months ago

thanks buddy.

Great tutorial thanks! I just open my old remote control and found S8050.

its just fine.could you tell me why the multimeter shows 1 when the transistor is in good condition?

Hey vignesh !!

You asked a good question..

When we measure resistance of an object then a multimeter shows

the value.

but have you wondered if the object is a insulator like wood,plastic ++

then the resistivity can't be measured cause the electricity can't flow

through them at all because of their infinite resistance.

In this case expensive multimeters will display "O.L." (open loop).

and cheap meters will display only '1' means the same(infinite resistance/open loop).

Hope it helps :)

uzzal saha1 year ago