Keyboard is getting power, but nothing else.

When I press the power button, I hear a click in the Superdrive, as if it's excepting a disc, and then I hear the hard drive starting to spin up. Then a second later, the hard drive whines down and appears to stop. The "F6 - Number Lock" key on the keyboard also illuminates green up when pressed. The power supply is green when plugged in the Powerbook without the battery and then amber when the battery is installed with one blinking light on the battery led.

So far, I've tried reseating the RAM as well as attempting to start the laptop with only one RAM clip in each slot. I've also tried unplugging the PRAM battery as someone had suggested on ifixit.com, but still the same results. It powers up the same everytime, the Superdrive and then the hard drive. The screen remains off and no Apple chimes, only the keyboard seems to stay on.

Has anyone gone through this same scenario and been successful in finding a solution to the problem(s)? So far, I've read a lot of suggestions, but not anything that actually fixed this sort of thing. Please help! Thank you in advance.

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I zapped the PRAM and now I hear the Apple chime, which I didn't hear before. However, there is still nothing on the screen and the Superdrive and hard drive are still doing the same thing as before, clicking noise as if you're loading or ejecting a cd/dvd and then hard drive makes a few sounds as if it's booting up and then appears to stop.

The power supply appears to be working, because the external battery takes a full charge when plugged in. I checked the PRAM battery and it registers at 4.16 volts and it's a 3.75 volt battery. The output of the battery is 6.51. So, I don't think the PRAM battery is the problem, unless it's outputting too much DC power. I even disconnected the PRAM battery, as some have suggested, but still no change or difference.

Does anyone have any other suggestions?

Thank you in advance.

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Hi! What is the history of this machine, and have you seen it working correctly in the past, or did it come to you in this condition? If you've seen it working, what happened between the time it was working and when it started behaving as it is now? Along the same lines, is this known-good RAM, i.e. have you witnessed it working in this computer or another?

When you state that there is no video, have you used a flashlight to look through the Apple symbol from behind, i.e. is there possibly a faint image? If there is, that could indicate a bad screen, or a crimped inverter cable. I would also try connecting to an external display. If you get an external picture, that means some part of your computer's onboard display hardware (screen, cabling, etc.) is at fault.

In general I would start troubleshooting by removing or disconnecting everything that is not relevant -- optical, hard drive, one of the RAM modules, and the battery. At this point they are all a distraction from the real issue, which is that you've got a non-working computer. Once that's resolved, you can work backwards and start adding components.

Do you have a 65W AC? 15" PowerBooks work best with 65W, and sometimes will fail to power up with 45W. If you do have a 65W AC, have you witnessed it working on this or another laptop? A lot of the time people get stuck because parts they thought were good are actually bad...as a general rule I never trust a part unless I've seen it working with my own two eyes.

Also, is the sleep light on, or pulsing? It's conceivable there is a sleep issue, and that the computer is being forced to sleep. I'd take the topcase off completely and bridge the power-on pads, to see if it behaves the same without the topcase connected.

If none of this makes a difference, it's conceivable it could be a video chip issue. PowerBooks don't have video issues on the board as commonly as the 15" Pros do, but it does happen from time to time.

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First try Resetting your Mac's PRAM and NVRAM, here's how: http://support.apple.com/kb/ht1379

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Craig will be eternally grateful.
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