• Hello, Guest! Welcome back, and be sure to check out this post for more info about the recent service interruption and migration.

PowerBook Duo 270c Restoration

m68k

New member
Hello,

my beloved 270c just died and I consider an attempt of restoration including re-cap. Fotos of suspected faulty areas attached.

Can somebody please help with an evaluation for the chance of success and the specs/ details of the required electronic parts?

I have not yet disassembled the display - are there more parts which should be replaced?

Cheers,
M.
 

Attachments

  • 1.jpg
    1.jpg
    163.7 KB · Views: 11
  • 2.jpg
    2.jpg
    205.5 KB · Views: 12
  • 3.jpg
    3.jpg
    42.1 KB · Views: 12
  • 4.jpg
    4.jpg
    106.4 KB · Views: 12
  • 5.jpg
    5.jpg
    194.4 KB · Views: 10

joshc

Well-known member
Hello, and welcome to the forum.

It looks like a few components have failed, hard to say why or how that's happened (I am not super familiar with these I'm afraid).

It all depends on how much time and energy you want to put into trying to save it. Most of the components have markings/ratings on them, so just follow that to find the replacement. As for the burnt/dead capacitor in photo 3, it's a ceramic capacitor and it's probably of a low value similar or the same as the one below it - you could measure C225 out of circuit and go from there.
 

m68k

New member
Thanks! As for C82 (photo 2): is that one eventually missing (by intend)? Looking for a photo of an intact 270c board... Are detailed circuit diagrams somewhere available? Would it work to replace the board with one from a 230 (I also have) - or just swap the displays between 230 and 270c...?? :)
 

Juror22

Well-known member
Just looking at the Service Source I think it would be unlikely that the displays or boards could be swapped, if I am understanding your question correctly. The display cables for each are significantly different. Its hard to predict how possible a repair would be for this board, but some of the folks here have brought some boards back to life that I would have thought were unsalvable. Your board looks like it could be fixed by replacing a few components (along with eliminating whatever initially cased the issue) and largely comes down to your skill level, or how much time that you want to invest. If I can find any more information, I will pass it along.
 

bdurbrow

Well-known member
Has this machine been in a particularly humid environment, or had anything spilled on it? I'm seeing an awful lot of corrosion, but not much outright leakage from electrolytic caps (at least, in the photos posted). Yet. The caps will - sooner or later - leak. They always do.

If any custom chips have been damaged, you would need a parts donor machine from which to extract a working replacement chip. Otherwise, the motherboard itself may be fixable; high-resolution photos of both sides of the entire board would help in making an overall assessment.

If the display has been damaged, you would need to get one from a donor machine.

Generally speaking, this machine needs a full capacitor replacement, several damaged pins replaced, and at least one MLCC capacitor has exploded (probbably caused by, and still causing, a short from a power rail to ground). Also, the board needs to be cleaned; residue from

Note that I'm just going on accumulated electronics knowledge; the last time I had a Duo 270c in my possession it was still quite new, and didn't even belong to me (was provided for work).

P.s. - even if you decide not to attempt a repair (or are unsuccessful), you may be able to sell it as a parts donor machine. If the case, keyboard, and trackball are in good shape, it might even be useful for a Raspberry Pi conversion project.
 

m68k

New member
I used this device regularly (since 1995) in the same clean home environment (mainly as a midi sequencer), usually always on/ sleeping. The last thing I did (in March) was to install SetDate to fix the Mac OS 7.6.1 Y2k20 date bug :). The nice color display always worked fine. The machine has max. RAM (32MB) and (since many years) a silent PowerMaster II CF. Btw. I also have most of the peripherals (Floppy, Mini/Dock, PowerCD etc.) - love this old stuff ;-). I suppose the elcos already leaked which caused the burnt ceramic. Attached is a photo I took before I initially cleaned it. Still wondering if C80 (not 82) fell apart/ disappeared (probably) or never was there...
 

Attachments

  • 6.jpg
    6.jpg
    117.3 KB · Views: 6
Last edited:
Top