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Hi guys! I bought this Powerbook 165 on eBay for 10 quid last week, the seller already stated that it was broken but I liked the idea of having a project to repair a Powerbook. At the end I would like this to become a big guide so other people with similar problems will find it helpful.

 

So far I found these problems:

 

  • [solved] Power Adapter:  At first the Powerbook won't turn on, testing the PSU with my multimeter I found that it wasn't given the correct voltage (the correct is 7.5V), a quick recap and it was up and running! (well, up and giving power). Now the Powerbook boots but I found other problems.

 

  • Trackball: When I use the trackball it only moves the cursor vertically, disassembling it I found something interesting: When the ball is inserted on the centre of the board, due to the weight of it the wheel mechanism is slightly moved, The y-axis sensors can still capture movement but the x-axis sensors cannot, if I take away the ball and turn the wheels manually both sensors work. Maybe the x-axis sensors doesn't have enough power? I replaced the 2 transistors on the board and it still gives the same result. I tried to bend the sensors a bit but it still won't work and I don't think is the correct solution. Here are some pics to understand the mechanism:

Here is the trackball board, the x-axis sensors are on the upper-right corner

post-4547-0-83525100-1455967456_thumb.jpg

 

This is the trackball board with the wheels 

 

post-4547-0-23060600-1455967639_thumb.jpg

 

And finally a zoomed picture showing the x-axis sensors with the front wheel, it slightly move left when the ball is inserted

 

post-4547-0-05136300-1455967749_thumb.jpg 

 

  • Screen: Ugly lines appear until I mess with the contrast and brightness controls, capacitor problem or irreversible?

post-4547-0-49608200-1455968051_thumb.jpg

 

  • Energy distribution: This is odd, sometimes the hard drive only turns on when I turn off the screen, and sometimes the laptop shuts itself down, the PSU is giving the correct voltage.

 

  • Hard drive: Doesn't appear to detect it, does some strange sounds when it turns on.

Any help, and I mean ANY will be VERY appreciated, I'll be updating the list and posting solutions as we go.

Edited by jua958
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Trackball: optical alignment is critical to get the correct quadrature output, if all else fails, replace it. 

 

Screen: Normal, and it also needs caps eventually. 

 

Energy distribution: Thats a unique name for it... But, again normal with a failing HDD. 

 

Hard Drive: Dead... replace it. Common issue, and getting unobtanium. 

Edited by techknight
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On the trackball, I'd guess that the end of the shaft the wheel and blue roller are mounted on is supposed to go into something on the black plastic frame to keep it from moving on that side.  The side with the blue roller on it is free to move back and forth, but there's a spring to push it against the ball, however the side with the wheel should not be able to move much.  Take a look at how your side that's working is assembled, it may simply be that the shaft isn't going into the plastic frame, or maybe the frame is broken.

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Thanks for the quick replies!!

 

Trackball: optical alignment is critical to get the correct quadrature output, if all else fails, replace it. 

 

Screen: Normal, and it also needs caps eventually. 

 

Energy distribution: Thats a unique name for it... But, again normal with a failing HDD. 

 

Hard Drive: Dead... replace it. Common issue, and getting unobtanium. 

 

Yeah, at the end I removed the hdd and now the 2 last problems are gone, it's a shame that the whole 160mb hdd has to be wasted only because of the click of death, but I'm not gonna throw it just jet, probably in the future I will be able to repair it.

 

 

On the trackball, I'd guess that the end of the shaft the wheel and blue roller are mounted on is supposed to go into something on the black plastic frame to keep it from moving on that side.  The side with the blue roller on it is free to move back and forth, but there's a spring to push it against the ball, however the side with the wheel should not be able to move much.  Take a look at how your side that's working is assembled, it may simply be that the shaft isn't going into the plastic frame, or maybe the frame is broken.

 

A wee piece of napkin in the hole where the wheel is subjected and the problem was gone, Yaahoo!

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To be more specific on the optical alignment, picture this: 

 

If your staring down the shaft in the middle, the opto-coupler sensors on both on the right side, and left side of the disk. 

 

The disk has multiple slots in it. (try not to think lude here during this post please, I am being serious). 

 

When one set of sensors has a slot over it, the light passes through. However, the 2nd set should have no slot at all, it should be in between slots. And vice versa. As the disk rotates, the right sensors get covered while the left sensors uncover. 

 

Each group of sensors will lead or lag one another depending on the direction of rotation. thats how the quadrature system works. 

 

So, if the alignment is off, both sensors will be covered up at the same time, or they both will uncover at the same time. This confuses the decoder.

 

Lateral movement of the disc side to side should NEVER affect this. HOWEVER, vertically, if it has any play at all top to bottom, it will cause this problem. Or if the sensors get bent, or replaced and re-seated at the wrong vertical height. 

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