PowerBook 160 Repairs

jmacz

Well-known member
I recently picked up a cheap PowerBook 160 to help test my SD Aide utility. I got it super cheap from a friend. Although it ran and fulfilled its testing purpose, I figured I should fix it up instead of letting it die. It came to me with lots of physical chassis issues (falling apart) and the LCD display did not work (no image, just the backlight turns on).

Display and Electronics

This was apparently the second LCD inside this PowerBook 160. I was told the previous one had died, been recapped, but still didn't work, and so a second LCD was acquired, that worked for a few months but then also died. A new inverter board was also acquired but that did not help. I took the PowerBook apart and here is the display capacitors:

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Capacitor leakge was visible, there was some minor corrosion on the pins near the various capacitors. Some of the capacitors were barely hanging on (as you can see from the photos) and one of the pads was lifted (C1) and barely hanging on. The picture above was with the capacitor still on the board but I had cleaned up the corrosion. After removal of the capacitors, you could smell the leak. Yuck. I took the old capacitors off, cleaned the board, fixed the pad, cleaned up the other pads, and put new tantalums on:

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@3lectr1cPPC's capacitor list was correct and allowed me to get the capacitors ahead of time so that after taking apart the unit, I could go to work right away instead of reading the capacitor specs and waiting to order the replacements.

The inverter board also needed to be recapped. Although the polymer one probably didn't need to be replaced, I replaced both just to be sure. Also replaced the caps on both of the inverter boards I got with the unit:

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While I was at it, I replaced the single capacitor on the trackball unit. The trackball itself was a little sticky so I ended up cleaning the entire mechanism and it works perfectly now.

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Lastly for the electronics, I replaced the PRAM coin battery. It's soldered onto a board but easy to remove. I replaced it with a new Panasonic VL2330 lithium battery.

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Physical Chassis

As usual, the plastics on this PB160 had degraded over time. Super brittle. I had heard rattling inside the laptop and sure enough, almost all of the standoffs had broken off. Some of the carnage:


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Ouch. So had to go and design new parts to replace these stand offs (I will attach the STL files at the bottom of this post). Note the small cylinder and the other part are not part of the standoffs obviously. More on those pieces later.

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First was to remove the existing standoffs. Most of it crumbled away but I used a dremel to grind away what was left behind:

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Next I used a combination of super glue and epoxy to put in place the 3D printed replacements which were printed with ABS.

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Then had to place in the brass inserts. These were the stock brass inserts.

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And then back together it went. Everything is working :)

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jmacz

Well-known member
Attached are the STL models for the new standoffs.
 

Attachments

  • standoffs.zip
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jmacz

Well-known member
Now with regards to those two other model parts I mentioned earlier. The rear port cover had broken off and the end caps on the two feet were also broken. Here's the port area:

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First step was to clean up the area so that it could take a new hinge:

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Use a dremel and an x-acto blade to get it as square as possible. And then 3D printed this guy:

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I only need about a 1/3 piece of this so cut out a little pie slice from this piece. Then grafted it on with super glue:

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This was pre-sanding. But it does work properly holding the door and letting it swivel open/close. Working on painting this so that it doesn't stick out so much.

The other part which is the cap for the feet, that's still a work in progress. The original model was slightly off so making some revisions now.
 

mitchW

Well-known member
Very nice! I went through same steps on my PB 140 and 160 :)
Mine had failing hinge mounts on the LCD cover, which was fixed with 3D printed bracket
 

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    IMG_0043.jpeg
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3lectr1cPPC

Well-known member
By the way - what CAD software do you use? I need to sit down and teach myself. One of my PC laptops that I already filled with epoxy has exploded at the right hinge again, needs 3D printing at this point… gonna have to design my first part.
 

jmacz

Well-known member
I think a lot of folks are using FreeCAD.

I'm still using Fusion 360 (free hobbyist version) because I also prefer integrated CAM functionality which i need for my milling projects.
 

jmacz

Well-known member
Opened up the battery pack today. No smart battery circuitry. Just thermal fuses and looks to be two sets of 5 batteries wired in parallel.

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Each cell measures about 16mm diameter by 49mm length.

Will search the forum for the overall voltage and see what I can fit inside the same space.
 

desertrout

Well-known member
Opened up the battery pack today. No smart battery circuitry. Just thermal fuses and looks to be two sets of 5 batteries wired in parallel.

View attachment 76958

Each cell measures about 16mm diameter by 49mm length.

Will search the forum for the overall voltage and see what I can fit inside the same space.
6V nominal (1.2V x 5). I've built a couple (only one really successful one) using AA flat top NiCd's, fit great but fussy to build (I was soldering tabs on, ideally should use a spot welder). Others have had success with the 6V NiCd battery packs used for RC cars (I have a couple on order and am going to try this), two of which should fit.
 

jmacz

Well-known member
So for the ones you built, you went with 5 cells only instead of 10?

I left a note in this thread:


But not clear to me whether it's ok to charge two of these packs in parallel via the stock charge mechanism (powerbook and power brick). Although of course the stock battery did have two parallel sets of cells, but I guess I'm asking from a NiMH replacement perspective.
 

desertrout

Well-known member
So for the ones you built, you went with 5 cells only instead of 10?
I used 10, copying the original configuration, reusing all of the components.

But not clear to me whether it's ok to charge two of these packs in parallel via the stock charge mechanism (powerbook and power brick). Although of course the stock battery did have two parallel sets of cells, but I guess I'm asking from a NiMH replacement perspective.
Hard to say without knowing the charging topology of the PB, but I believe it's not all that clever, and given NiCd and NiMH have different charging profiles I'm not sure show sensible it would be to charge NiMH using the stock charging mechanism. You can always experiment.

As for charging parallel packs together, perhaps that's a good reason to build batteries using individual cells so that you can control / balance their construction. Alternatively, if you want to go the pre-made RC pack route, just use one five-cell pack that's decent capacity.
 

jmacz

Well-known member
Ok, I will play around. Seemed like a few packs were built in that other thread using NiMH and might be charging via the stock charing mechanism which I thought might not be safe. But we'll see if anyone responds in that thread.
 

jmacz

Well-known member
Thanks for the link. So it seems very basic, applying some fixed current up until 7.5V and then using a constant voltage up until 7.9V. The issue would be if two packs are unbalanced. Like you mentioned, I could build balanced packs via individual cells but isn't it still possible that the two packs go out of balance over time?

Seems like it would charge NiMH (single pack) ok given it's not utilizing some peak detection mechanism. Seems like it just has a cut off voltage.
 

jmacz

Well-known member
Decided to try NiCDs first.

Found a pack that is 50mm x 70mm x 14mm and ordered two of them. Theoretically both should fit as the stock battery had ten A size cells which are 50mm length x 17mm diameter and thus had two sets of 50mm x 85mm x 17mm. Also picked up some thermal fuses.

Capacity is 1800 mAH per pack and thus wired in parallel should provide 3600 mAH on paper. I think I read the stock battery pack had a capacity of 2800 mAH.

Other folks seems to have gotten pretty crappy run times with rebuilt batteries. Not sure why that is if the stock battery truly had a capacity of 2800 mAH. One thing that @alexGS mentioned in an unrelated 500 series battery topic is that the presence of a working PRAM battery really helped improve his battery life. A guess as to why is that on the 500 series, the PRAM battery is charged by the main battery and if it's dead, it could be draining the main battery while attempting to charge the PRAM battery. The PowerBook 160 also uses a panasonic rechargeable coin cell for the PRAM battery. I'm curious if folks having crappy battery life swapped out the PRAM battery or not. I've put a brand new Panasonic battery in place so we will see.

The NiCDs arrive in a few days. Will give it a try then.
 

jmacz

Well-known member
Installed two packs of 6V 1800 mAH NiCD batteries (in parallel). The PowerBook 160 is booting with just the battery. But I'm going through a charge cycle to see whether this is going to provide any meaningful runtime.

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The two packs fit well into the stock battery case. I have a thermal fuse in there as well.
 
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