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Replace MOSFET AO4433 With FDS6679

brunobox99

Apr 10, 2018
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Good day guys. This is my first time posting, hope you can help me a bit with this.

My Sony Vaio laptop from 2009 has two damaged AO4433 MOSFETS near the power supply connector. I want to replace them, but I can't find this exact model in my city. I have an old laptop motherboard (for spare parts) that has some FDS6679 MOSFETS that I can use.

Can I replace the damaged AO4433 with the FDS6679?

Thank you very much in advance for your help.
 

Cannonball

May 6, 2017
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Look up the specs. and compare them, If they equal or exceed your requirements it will work.
 

brunobox99

Apr 10, 2018
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Look up the specs. and compare them, If they equal or exceed your requirements it will work.
The major difference is the Pd. In the AO4433 is 3 W, and in the FDS6679 is 2.5 W.

Would it still work? I dont know much of electronics, I'm more a hobbyst than a technician.
 

hevans1944

Hop - AC8NS
Jun 21, 2012
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There are some differences, the most notable is that FDS6679 has more than 2.5x the gate charge.
Do you even know what that statement means? This is a direct quote from a response to the same question here that you also cross-posted to Electronics Stack Exchange.

We here at Electronics Point are now waiting with bated breath for your next post on www.edaboard.com, where you stated that you are going to go ahead and try replacing the AO4433 mosfets with two FDS6679 MOSFETs salvaged from your other motherboard and report back the results there.

You apparantly also liked Dodgydave's unsubstantiated opinion that the FDS6679 has a "better spec" as he responded to your query on the All About Circuits forum here.

Are you not aware that it is considered poor form to post the same question on multiple forum sites simultaneously? Why are you wasting our time here on Electronics Point?
 

brunobox99

Apr 10, 2018
6
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Apr 10, 2018
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Do you even know what that statement means? This is a direct quote from a response to the same question here that you also cross-posted to Electronics Stack Exchange.

We here at Electronics Point are now waiting with bated breath for your next post on www.edaboard.com, where you stated that you are going to go ahead and try replacing the AO4433 mosfets with two FDS6679 MOSFETs salvaged from your other motherboard and report back the results there.

You apparantly also liked Dodgydave's unsubstantiated opinion that the FDS6679 has a "better spec" as he responded to your query on the All About Circuits forum here.

Are you not aware that it is considered poor form to post the same question on multiple forum sites simultaneously? Why are you wasting our time here on Electronics Point?
hevans1944, excuse me if you consider posting the same question on different boards inappropiate. I just wanted some opinions in regards to what I was going to do with my laptop. As I said in another forum, I am not an EE nor a technician. Just a DIY kind of person. Again, excuse me if I posted in other forums, but I don't think that it is something wrong or bad, to look for different points of view. And thanks to the members who cared to answer my question. Have a good day, hevans1944.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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If you're going to post in multiple places, it would be useful to post a link to your other posts, or at least mention the fact.

It means that people don't duplicate effort, and you don't have to read the same stuff twice.

My preference is that you pick one place and don't post elsewhere unless you fail to get a response.
 

brunobox99

Apr 10, 2018
6
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Apr 10, 2018
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If you're going to post in multiple places, it would be useful to post a link to your other posts, or at least mention the fact.

It means that people don't duplicate effort, and you don't have to read the same stuff twice.

My preference is that you pick one place and don't post elsewhere unless you fail to get a response.
Thanks for the clarification, Steve.

I will follow your advice from now on.
 

hevans1944

Hop - AC8NS
Jun 21, 2012
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As I said in another forum, I am not an EE nor a technician. Just a DIY kind of person.
Well, hopefully you have some interest in becoming a DIY electronics kind of person. That is what this forum is for. Read the "About Us" statement at the bottom of every page: Electronics Point is a community for members to discuss, advise and debate electronics related topics. It's really hard to participate in a meaningful manner if you don't know anything about electronics. We do welcome newbies willing to learn, and there are some resources available here that could help, but this is not a teaching forum, per se, it is a discussion forum. Anyhoo... welcome to Electronics Point! Please let us know how the parts substitution turns out.

We are not a problem-solving service, although members here help other members who show an effort to help themselves. We get a lot of drive-by posters just seeking quick answers, mostly "monkey see, monkey do" DIY types. Some of those folks will receive help if the answers are simple and don't require a lot of research, or if the poster can be directed to an online reference that will help them solve their problem. Your situation is NOT like that. You ask for expert opinion to select between two candidate devices to be installed on a complicated piece of electronics. You offer nothing in return, not even a description of possible causes for the failure of the original part. Then, if you replace the component with a substitute and it fails, what are you going to do?
 

brunobox99

Apr 10, 2018
6
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Apr 10, 2018
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Fortunately, the laptop didn't catch fire. (I was not expecting that, really).

I have been testing it with Memtest86 for a while, and seems stable. The laptop has not crashed / rebooted / shutdown.

Thanks to all who replied. I can confirm it works OK, but just for this particular situation. I don't know how it will work in any other scenario.
 
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