Motheboard Power

Hi. My toshiba satellite A70 stopped charging from the ac port. Every time I plug in the ac, the light just flickers and the fans spin on and off continuously.

Seeing how there's a common problem with the ac power jack in these series, I bought another one, replaced the old jack, but still the same problem. Then I examined the motherboard (should have done that first, I know...), and saw a chip that's kind of melted. It was an Anachip AF4407P, a MOSFET.

Putting some solder to bridge connections from the chip to the M/B kinda fixed the problem, but would only last 2 or 3 minutes.

My question is, can I buy just any mosfet on the web, and it'll work? I found a AF9945N on ebay pretty cheap. Or any common electronic device where I can pull one?

Thanks in advance.
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  1. No you can't just buy any mosfet. Even if you found the exact chip, this is not something I would recommend but seeing how your PC is non-functional right now, why not mess around with it?
    Unless its under warranty, Most likely you'll have to get a new lappy. With that solution looming, like you I would be inclined to see what I can do with the toshiba. Unfortunately we have no idea if that one mosfet will correct all your problems. But I wouldn't assume that a similar series of mosfet would fix your PC, there are prolly thousands of different little mosfets made for this type of application. I think its likely they would all have similar but not exactly the same voltage/current requirements.

    The reason I believe you'll have a difficult time is, well have you ever tried to find a replacement power supply for a laptop? If you did, you'd find that they are rated differently for each model, they are all over the place and there is no standard volt/amp requirements for these things, I hope this answers your question, or at least prepares you for the possible outcome.

    BTW, I've found that replacement motherboards are more expensive than a brand new machine.
  2. Hey thanks buzznut. Well I read on some other forum of people pulling a mosfet off another non working m/b to fix theirs, and it worked for them. Also, some people fixed their mosfet problem by putting in a completely different one, and it worked, albeit for different uses and not for motherboards, that's why I wanted to make sure.

    I'm definitely not sure if the mosfet would correct my problem, but I'm willing to try, and the fact that I was able to go into the bios once I bridged the chip to the motherboard gave me some confidence.

    As for buying the exact same mosfet, the AF4407P is petty much inexistent on line, the only thing I found were data sheets, and seeing how you mentioned the volt/amp are non standard, what am I looking for in a chip in order to get the closest one possible?
  3. I really don't want to waste this laptop, so if anybody can help me get it back up and running I would greatly appreciate it.
  4. Best answer
    Try to look for a MOSFET with similar specs.
  5. Ordered a chip that seemed close enough from eBay, here's to hoping it'll work.
  6. Best answer selected by hacman.
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