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strickerj

Q: Powerbook 145 apparently dead

I have a Powerbook 145 that I bought used around 1998, and it died in 2000. I suspect a power issue since hitting the power button on the back yields no response at all - no lights, chime, etc. I've confirmed using a multimeter that the AC adapter works and the battery is completely dead. Does this machine require a startup surge beyond the AC adapter's capacity (i.e., replacing the battery might resolve this problem), or is it likely the internal power supply, or something else?

I'd really like to get this fixed so I can see my applications and documents as they were 10 years ago before the machine died (though admittedly I have no idea if the hard drive still works). I can get a new battery with a warranty on eBay for only $30, but any other parts (or entire systems for sale) seem to be very hard to find.

Thanks in advance!

Mac Pro 8-Core (2x 2.26 GHz Xeon 5500-series), Mac OS X (10.6.3), 10 GB RAM, 2x 750 GB HD, Radeon HD 4870, 24"LED Cinema Display, Nikon D300 w/GPS

Posted on Jun 7, 2010 8:43 AM

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Q: Powerbook 145 apparently dead

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  • by Jan Hedlund,

    Jan Hedlund Jan Hedlund Jun 7, 2010 9:47 AM in response to strickerj
    Level 6 (9,894 points)
    Jun 7, 2010 9:47 AM in response to strickerj
    Hi,

    Does this machine require a startup surge beyond the AC adapter's capacity (i.e., replacing the battery might resolve this problem),


    Some PowerBook computers (such as the 180c) require an AC adapter with approx. 24 W (7.5 V DC, 3 A) output, but the PB 145 should be fine with an approx. 15 W (7.5 V DC, 2 A) version.

    Have you tried with the main battery removed?

    or is it likely the internal power supply, or something else?


    It may be worth checking whether there is an SMD fuse (usually called F1) near the battery contacts on the main board, and that this fuse is OK.

    Jan
  • by strickerj,

    strickerj strickerj Jun 7, 2010 10:38 AM in response to Jan Hedlund
    Level 1 (15 points)
    Jun 7, 2010 10:38 AM in response to Jan Hedlund
    Oh, well I have a 24W AC adapter, so that answers the first question.

    With the main battery removed, it still doesn't respond.

    There is a little block labeled F1 on the board near the battery contacts (doesn't look like any fuse I've ever seen though). I was examining it and accidentally broke it off the board... I think I've successfully put it back to where the tips are making contact again, but I have no idea how to check if this fuse working.
  • by Jan Hedlund,Solvedanswer

    Jan Hedlund Jan Hedlund Jun 7, 2010 11:29 AM in response to strickerj
    Level 6 (9,894 points)
    Jun 7, 2010 11:29 AM in response to strickerj
    There is a little block labeled F1 on the board near the battery contacts (doesn't look like any fuse I've ever seen though).


    That is an SMD (surface mount device) fuse. This web page shows one example.

    Off the board, it would have been easy to check that fuse; just use an ohmmeter (look for a near zero reading).

    When soldered to the board, the surrounding circuits complicate matters. Still with an ohmmeter, one can try to carry out the test in both directions (should read almost zero in both). I should add that there is always a certain (albeit relatively rare) risk that an in-circuit test negatively affects other components.

    Jan
  • by strickerj,

    strickerj strickerj Jun 7, 2010 11:28 AM in response to Jan Hedlund
    Level 1 (15 points)
    Jun 7, 2010 11:28 AM in response to Jan Hedlund
    Well, I'm not sure how accurate this is (using the same multimeter I used to check the battery and AC adapter), but it's showing substantial resistance (on the order of megaohms) across the SMD (in both directions, obviously). So I'm guessing that's it... I don't suppose there's any way to replace that fuse?

    Thanks very much for helping me diagnose this.
  • by Jan Hedlund,

    Jan Hedlund Jan Hedlund Jun 7, 2010 11:51 AM in response to strickerj
    Level 6 (9,894 points)
    Jun 7, 2010 11:51 AM in response to strickerj
    Hi again,

    I just edited my previous message. You should not have difficulties finding a suitable fuse. If necessary, an SMD fuse can be replaced through (careful) manual soldering.

    It is quite possible that something else (causing the fuse to break) has to be replaced too. Do inspect other components for obvious signs of damage, especially electrolytic capacitors (also SMD).

    Jan