PSU Live 1A Fuse blown repeatedly

Hi,

I have one PSU which the Live 1A Fuse blows repeatedly. I read that changing the rectifier should solve thisproblem. However after changing the rectifier, the fuse continues to be blown. Any advise?

Thanks. SeventhPrince???

Reply to
SeventhPrince???
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Find the short.

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Reply to
CJT

Check the capacitor and regulating semiconductors. Bob AZ

Reply to
Bob AZ

CJT wrote in news: snipped-for-privacy@prodigy.net:

Probably a shorted switcher transistor or secondary diode. He should find a book on how switching power supplies work,or read the application notes for the UC3842 IC.

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Jim Yanik
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Reply to
Jim Yanik

Did you test the rectifier or just blindly replace it? If you're not able to test semiconductors you'll dump a lot of money into this thing trying to get it going and may well still fail.

Reply to
James Sweet

I have one PSU which the Live 1A Fuse blows repeatedly. I read that changing the rectifier should solve thisproblem. However after changing the rectifier, the fuse continues to be blown. Any advise?

Thanks. SeventhPrince???

Surely, the very first question to ask, before any of us can help, is what type of supply is it - switch mode or linear ? Then the next one has got to be, is the right fuse type being used ? If the supply has a damned great transformer in it, and some big smoothers to stick an additional heavy load on besides the core magnetization current at switch on, then if a ' T ' rated fuse is not being used as the replacement, it may well keep blowing at switch on.

Arfa

Reply to
Arfa Daily

How do I differentiate between these 2?

Yes, correct rating fuse is used. What are 'T' fuse and 'big smoothers' ?

Thanks.

Seventh Prince

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How do I test the rectifies? Thanks

Reply to
=?UTF-8?B?5LiD5bCR54i3U2V2ZW50

In all honesty, if you don't know how to tell apart switchers and linears, don't know how to test a rectifier, don't know what a smoothing cap is, and are able to determine that the fuse you are fitting is " correctly rated ", without knowing what a ' T ' spec on a fuse is, then I don't think that you are ever going to get to the bottom of the problem with or without the group's help.

Power supplies, particularly switchers, are dangerous, and someone with your apparent lack of knowledge should not be attempting to work on them, for his own safety ....

Arfa

Reply to
Arfa Daily

able to

get

It sounds like you've got a lot of homework to do before you try repairing something, I assume you haven't read the sci.electronics.repair faq?

Reply to
James Sweet

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=?utf-8?B?U2V2ZW50aFByaW5jZeS4

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