trouble with trouble shooting??

Thread Starter

Bigcountry

Joined Jul 4, 2008
76
I am really having trouble with this problem attached. I don't know if I am over looking something simple or not. It could be I am just tired from working all night. hopefully someone could get me pointed in the right direction.

thanks for any insight.

I would Check C4 for high leakage current.
 

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studiot

Joined Nov 9, 2007
4,998
When doing these it is a better exercise if you work through each option and know why you have discounted it.

A Some of the supplies are pretty close to nominal. this would not be the case with shorted rect diodes.

B R1 open would produce zero output at F

C This leg of the output is likely to be at lower current but voltage is not as low proportionately as the third leg.

D All the highly disturbed outputs are fed from C4

E C9 going open would only affect rail D, not the others

F Shorts on any of these capacitors would lead to zero output

G The psu worked once so changed values are always possible, but not wrong ones.

There I haven't (quite) done it for you.
 

RiJoRI

Joined Aug 15, 2007
536
Another thing that might help is to write in the erroneous voltages next to the correct ones. Doing that makes the probable answer pop out at you.

Check out The Universal Troubleshooting Process at http://www.troubleshooters.com/tuni.htm, especially their 10-step process. (No, you do NOT begin with "I am a recovering troubleshooter"! :D )

--Rich
 

Thread Starter

Bigcountry

Joined Jul 4, 2008
76
Thanks for the help. that helps a lot. So I think I was right with C4. right? that helps with writing the erroneous voltages on there too. It is hard to work a full time job and go to college. I don't have much confidence since I am kind of just starting with electronics. lets hope I can become a Xpert in 10 step process. :)
 

beenthere

Joined Apr 20, 2004
15,819
Life gets very different when you are the person on the spot with a critical problem to fix located many miles from the support facility. You can never know too much about the equipment or electronics.
 
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