Checking caps, op amps, transistors in circuit?

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paulrichards7

Well-known member
Joined
Jun 10, 2008
Messages
68
Im having a noise issue on the collector leg of one of my transistors
I have been told to check the caps, op amps and transistors around it
As im new to the world of electronics, how do i go about checking these in circuit?
Thanks
Paul
 
What are you working on?
Tell us the model and maybe we can dredge up a circuit diagram.

Be careful around the transistors with the power on.
One slip of the probe and it could get zapped.
 
Studiomaster 16 4 8
Some of the channels have a lot of noise(white noise)and it seems to be coming from the collector leg of one of the resistors
http://i390.photobucket.com/albums/oo345/paulrichards7/Channeltrans.jpg
I have put a red ring around the culprit
Ive been told to check the opamps & caps around the transistor as well as the transistor, but I dont know how to do this
Thanks
Paul
 
A common problem is those coupling caps getting noisy.
That would be the cap with the + sign, up and to the left of the transistor.

Simply find the same value, at or above the same voltage rating, and swap it out.

If no joy, it might be the transistor itself.

Resistors do make noise, all the ones that I have seen do this are in high voltage tube circuits.

There might be a Parts Meta if you need to order something.

If you would rather check the cap before ordering, but do not have a cap tester:

http://www.groupdiy.com/index.php?topic=24434&highlight=leakage+checker
 
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