PowerBook G3 Lombard not starting - fine power adapter - looking for possible culprit

Discussion in 'PowerPC Macs' started by mac1984user, Jan 11, 2015.

  1. mac1984user macrumors 6502a

    mac1984user

    Joined:
    Dec 10, 2009
    Location:
    United Kingdom
    #1
    Hello there,

    I just bought a PowerBook G3 Lombard and used it with my iBook clamshell power adapter, which I know works. When I plug the adapter into the PowerBook, sometimes I see a green light on the left hand side light up. Once or twice, I could hear the hard drive spin up. However, I have not been able to reproduce this in the last 20 or so attempts. In a single instance, the screen turned on, but it had some streaking lines across a grey background and I could not see anything. In more recent attempts I have not been able to get any sign that the PowerBook is turning on at all (i.e. the hard drive makes no noise whatsoever, etc.). Sometimes, I see a green light when I plug the power adapter in, and sometimes there is no green light, or it only appears briefly. I am really trying to figure out what component might be the problem. My first instinct is to assume that it is the sound/AC card, which the power adapter plugs directly into. That might explain why there is some variation in terms of the experience. However, I cannot come up with a suitable explanation. I have tried numerous things beyond replacing any specific components quite yet. One of my first strategies was to disassemble the entire computer to make sure that all the connections were solid. After reassembling the computer, my experience was much the same. I have also kept the PRAM battery unplugged at different times, because I read somewhere that a bad PRAM battery can sometimes affect the power up. Does anybody have any suggestions as to what the culprit might be? Do you think I am right in believing it might be the AC/sound card? From your experience, might it be something else? Thank you for your advice in advance.

    Regards,
    Mac1984User
     
  2. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #2
    Here's a sequence that used to work for me (haven't had a Lombard series for about 10 years!)
    Remove main battery.
    Plug power adapter in.
    Press and release the reset button (on the back panel between the modem and video port)
    Let it sit with no battery, but power adapter plugged in for 48 hours.
    That process should charge up the backup battery (if it is any good).
    Is the main battery holding a charge at all? Re-insert after the 48 hours.
    Press the reset button again, then wait 5 seconds.
    Press and release the power button.
    Any response?

    Attempting to charge both batteries is a good thing to try, but you know it may be a waste if the batteries are quite old (or you already are pretty sure that both are bad), then I have no expectation that your PBook will boot.
    And, of course, if the sound card is faulty, then you won't get any more response.
    That's what I would try next, you said that the power adapter works fine on another PBook?
    There is also sometimes a difference when you insert the main battery in the right-hand slot. Take the CD out, and insert the battery in that slot. (maybe you already tried that!)
     
  3. weckart, Jan 12, 2015
    Last edited: Jan 12, 2015

    weckart macrumors 68040

    Joined:
    Nov 7, 2004
    #3
    I know that Pismos won't boot with a dead/depleted PRAM battery. Maybe the same applies to the Lombard. Try disconnecting that then restarting.

    [Edit] Ah, I see you tried disconnecting the PRAM already. If it still refuses to start, the other culprit (at least on the similar Pismo) could be the DC in board. This has power and sound sockets on it and both are more or less only attached by their solder connections. Frequent insertions/disconnections or sideward knocks can break one or more of the solder connections leading to loss of power and/or inbuilt sound. If the power socket feels in any way loose, then try disassembling your Lombard and get the soldering iron out. It is a very common problem with the later PB G3s. I have repaired the sound on one but failed to get dodgy power distribution on another one fixed. Sometimes the board can just go bad.

    The final thing might be failing RAM. If you only have one stick in your Lombard, I would try replacing that first.
     
  4. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #4
    I think that is correct. The main and backup batteries are interchangeable between the Lombard and Pismo.
    In case you need to find a replacement - Apple called that a "backup battery"
     

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