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Powerbook 100 Restoration

6

68k

Experienced Member
Joined
Apr 24, 2013
Messages
155
Location
Fort Worth, TX
Howdy!

I just purchased a Powerbook 100 from eBay for what seems like a reasonable price ($35).

The Powerbook comes with AC adapter, floppy drive, 8MB RAM, and original software.

Like most original Powerbook 100s, this one was listed as not working. The screen powers up but is "blank", and the hard drive is bad. The computer boots to a floppy disk and chimes as normal.

I wanted to make this thread not only as a work log for other PB 100 owners to use as a resource, but to gather ideas as to what I can do to make this a fun and reliable machine that will last long into the future.

Here is my plan:

-Replace all capacitors. Leaking or not, these are over 20 years old, and a common failing point for the PB 100. Capacitors will be replaced with solid-state tantalums that are not capable of leaking. The blank screen issue is a common sign that capacitors are shot.
-Replace dead HDD with Power Monster II 2.5" SCSI to CF adapter. These are a bit pricey, but work well. I use one in my X68000.
$(KGrHqR,!iIE69dK7WbhBO1Jnj618w~~60_35.JPG


Any ideas are welcome :)

The PB 100 is in the mail, but here is an auction photo from the original owner.

pb100_zps14b56ab9.png
 
I love the trackball on those. One of the best laptop pointing devices ever. I can't stand trackpads, even these new multitouch things. Never been comfortable with them.

If you spend a few extra bucks, you could get ceramic capacitors. They're significantly more expensive, but you don't have to worry about polarization, and they'll last a lifetime.
 
Ceramic will be the way to go. I don't want to cheap out on the build. Does anyone have an inventory of the capacitors I will need? If not, I can check them myself once the laptop shows up.

I have also toyed with the idea of upgrading the CPU to a 20 MHz 68000. I have a PLCC 20 MHz 68HC000 chip I could solder in for the upgrade, but my concern would be with the other components accepting the new speed.
 
It seems to me I recall reading there was a "blank" screen issue with early model PB 100's that was NOT capacitor related, I want to say they added some wire jumpers from logic board to CPU daughter card to fix it, if you don't see wire jumpers going to your CPU card, you might be looking at that issue as well. That said, it's likely the capacitors are failing and should be replaced even if that's not the cause of the blank screen.

I have a PB 100 doing the same thing, but I haven't dug into mine yet, just one of many vintage computer projects on back burner waiting for a rainy bored day ;-)
 
I will shotgun all of the caps and see where we are. It seems like there are always far more broken PB 100s than working examples out there.

I've wanted one for years, so it will be nice if I can make myself a nice working system.
 
68k said:
I will shotgun all of the caps and see where we are.
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Will not hurt it to replace all the caps, they have probably failed regardless of if it fixes the blank screen issue.

68k said:
It seems like there are always far more broken PB 100s than working examples out there.
Click to expand...
For sure, almost never come across working ones in this day and age.

68k said:
I've wanted one for years, so it will be nice if I can make myself a nice working system.
Click to expand...
I agree, I am a HUGE fan of all the early PowerBooks, they were so ahead of the curve in their day, such slim devices, with built in trackballs, beautiful displays, and long battery life.
 
olePigeon said:
If you spend a few extra bucks, you could get ceramic capacitors. They're significantly more expensive, but you don't have to worry about polarization, and they'll last a lifetime.
Click to expand...

If it's possible can you tell us more about the replacement?Can we replace the electrolytic ones with ceramics?Are the ceramic capacitors available in the (usually) higher capacities of the electrolytics?
 
I'm no expert, but I believe they can replace most of the electrolytic. I know for certain they come in the more common 16v 47uf that is in nearly all the Macintosh computers, and probably other voltages and capacitances. I don't know about their sizes, though. They look kinda like the tantalum capacitors, except they're usually white and, of course, ceramic. They're not marked because they're not polarized.
 
olePigeon said:
I'm no expert, but I believe they can replace most of the electrolytic. I know for certain they come in the more common 16v 47uf that is in nearly all the Macintosh computers, and probably other voltages and capacitances. I don't know about their sizes, though. They look kinda like the tantalum capacitors, except they're usually white and, of course, ceramic. They're not marked because they're not polarized.
Click to expand...

Do you know the failure behavior of ceramics? Aluminum Electrolytics usually fail open (and leak and explode, lol), Tantalum usually fail open as well (and explode with fireworks).

I certainly wouldn't see any problem using them as long as they also would fail open, if they fail shorted however, that could cause serious problems for the device they are installed in.
 
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Well, put this one to rest. The seller literally set the laptop in a box with no padding, so it proceeded to beat itself up in transit...

The Powerbook is ruined.
 
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68k said:
Well, put this one to rest. The seller literally set the laptop in a box with no padding, so it proceeded to beat itself up in transit...

The Powerbook is ruined.
Click to expand...

Ugh, Will sellers ever learn to package stuff properly? I just finished piecing a vintage turntable back together that was shipped in a similar manner.

Sorry to hear it, hopefully you didn't buy that expensive CF adapter in anticipation of it.
 
I will try to work a deal with the seller since this system has a 6MB memory expansion installed. That will be helpful with any future system I pick up.
 
That is terrible, he better refund you, and if you are lucky let you keep it for parts, its likely at the very least the keyboard and trackball, and possibly other useful parts may be salvageable.
 
I did get a refund and he is letting me keep the system for parts.

He was pretty upset about losing the laptop after having it since new (he was excited to know I was going to restore it), but what do you expect when you cram it into a flat rate box with no padding.
 
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