Dan Knight
- 2007.06.28
Pismo the Best PowerBook Ever
Adam Goff writes in response to What 'Book Should I Get?:
You mentioned that the G4 upgrades for the Pismo were in the $300-400 range. Leo can
pick up a 550 MHz G4 card from Wegener Media for
$199. Going from a 400 MHz G3 will result in a very noticeable
difference in speed especially if he throws in a 512 MB stick of
RAM, all of which can be done for under $300. If he wanted to go
all out, he can even pick up a wireless-g PC Card and an expansion
bay DVD/CD burner.
Even going from a stock 500 MHz G3 to the 550 MHz G4 in my Pismo
resulted in an overall sense of "snappiness" to the Finder as well
as any AltiVec-enabled applications. Your colleague Mr. Moore and I
have oft-lamented the venerable Pismo in correspondence to each
other. It's expandability and general ruggedness have made it, IMO,
the best designed Apple portable ever. Of which my seven years of
uninterrupted use is a testament to.
Adam M. Goff, IT Director
Ranch Hope, Inc.
Adam,
Thanks for writing. I checked Wegener Media's Pismo
page before replying to Leo LeBron, and I didn't see a listing
for the G4 card separate from a used Pismo. Going to the home page today, I see the
Pismo upgrade listed. I'll forward this info.
As someone who lived with a first generation
TiBook for over five years, I wish it had been as rugged as Pismo.
A lot of people had hinge problems and screws would work their way
loose from the bottom cover. It was thin, light, fast, and had a
widescreen display, but the Pismo was much more rugged and far more
expandable with its drive bay.
I think you'd get an argument from any WallStreet owner about which is the best
PowerBook design ever, since WallStreet had two expansion bays, but
the WallStreet, Lombard, Pismo
trio was a high point of versatility. Modern 'Books are more
powerful but not nearly as flexible.
Dan
Aging Capacitors and Tin Whiskers
Steve Lubliner writes:
Dan,
Electrolytic capacitors have been the bane of many electronic
systems for many years. Disciplines as varied as aerospace products
and antique radio restoration are affected. Yes, dried out
electrolytics are a cause of capacitor failures. Dried out
electrolytics are probably a lesser problem on modern design
parts.
A more significant problem deals with the basic physics of the
aluminum electrolytic capacitor's construction. The aluminum
capacitor relies on an aluminum oxide layer on the aluminum to
avoid conduction (shorting). The layer is extremely thin and not
100% perfect, due to minute imperfections (e.g., cracking). The
imperfections in the layer will allow conduction. The oxide layer
is "reformed" when a capacitor is charged by localized heating at
the conduction sites that recreates (reforms) the oxide.
A problem is an electronic system that has not been used for
many years, be it a "wooden round" missile (a missile designed to
be stored for long periods, say 7 years or more, without
maintenance), first turn on of an antique radio, or first use of a
rescued Mac after sitting in a closet for many years. The
dielectric film in the capacitors may have many conduction sites,
making the capacitor electrically look more like a resistor than an
open circuit. The heat from the many conduction sites causes the
capacitor to fail (or even explode) before the capacitor may reform
itself.
A technique used with antique radios is to initially power the
radio with a reduced current/voltage source (e.g., through a low
wattage light bulb) to allow the capacitors to reform without
generating excessive heat. I'm not recommending that for old Macs,
because the reduced power operation may damage other components
(e.g., the hard drives). The best preventative is a periodic turn
on; only once every 5 to 7 years will suffice. The attached article
has some information on reforming capacitors.
I've added some information on tin whiskers from a presentation
that made the rounds at work.
Steve Lubliner
Steve,
Thanks for the info - and the attachments. I can
see where tin whiskers are going to become a bigger problem as
manufacturers are being forced to create lead-free electronics, but
pure tin or tin with less than 3% lead may form whiskers, while tin
with at least 3% lead never does.
I was unaware of the use of aluminum oxide as an
insullator inside capacitors. Then again, I've never really
wondered what was used inside them. I recall from a paper I wrote
in high school that aluminum oxidizes very quickly in the presence
of oxygen, which gives aluminum a hard, weather resistant surface
if it's not coated.
I'm wondering what would be the feasibility of
disconnecting the hard drive (and probably the CRT as well, in Macs
with built-in displays) and creating a current reduction system
that could be used to restore old Macs before applying full
power.
Also, would it be possible to obtain permission to
include the image a the port with whiskers in a mailbag column?
Dan
Dan,
The images in the powerpoint presentation are "stock" photos
from NASA and other sources. There's no problem with them. In fact,
if you do a brief
"Google" search on tin whiskers you will probably find more
information than you care to know. NASA, for one, has excellent
information on the phenomena (seems that the space shuttle has
issues).
Relative to reforming the capacitors in our Macs: I'm one who
will probably accept the risk of smoke, smell, and possible loss of
the machine versus special efforts to reform the capacitors.
Probably the most common use for electrolytic capacitors in our
Macs is for power supply filtering. If the capacitor (in a filter
application) goes open, then you've lost the filtering. I'd take
the chance that operation would be restored (if the loss of power
filtering was critical) by replacing the capacitor, and no
permanent damage would be done.
If the capacitor (in a filter application) shorts, then you've
created a short across the power supply. I'm hoping, perhaps
wrongly, that the power supply will protect itself by blowing its
fuse. Of course, the "fuse" in this case may be another component
or a ciruit board trace. Like I said, I'm willing to take the risk.
(At least right now while the machines are relatively plentiful and
inexpensive. 25 years from now, when my LC is a "Collector's Item", I might have a
different opinion.)
Steve
eMacs Plagued with Bad Capacitors
A K-12 technician writes in response to Why Some Mac Die: Bad Capacitors:
The problem goes much further than the G5 iMac - much of the
product line of eMacs is plagued by the problem - to the point that
often replacement parts from Apple have been long delayed and
occasionally result in the them shipping a replacement machine. (We
once got two intel iMacs to replace two dead G4 eMacs!)
If eMacs had been sold in number to the general public, we would
be facing a recall I'm sure.
Please do not use my name - just refer to me as a k12 technician
from the field.
K12,
Thanks for sharing your experience. We used to be
big proponents of eMacs here at Low End Mac, and we still have a
couple of them. Each one has been in for service at least once, so
I have to say they are not the most reliable things Apple has ever
built.
Dan
Worse if you have to lug the 75 lb. machines around. Only the
AIO Power Mac G3 was of comparable
weight and prettier on the outside perhaps....
We've combed through hundreds and reported dozens or more of
popped capcitors. They tend to run fine until the do something
intensive like iPhoto and then they go into never never
land....
XPostFacto for Leopard
Will Schoumaker says:
Dan,
You and several others have mentioned XPFacto as
providing Leopard support for some older Macs. Do you have some
inside info, or are you just hoping and or guessing? Ryan R[empel],
the developer of XPFacto, has been missing from the XPFacto forums
since Dec 2005! He also hasn't been present at the Darwin lists,
where most of the work was done/reported on.
I used to be in contact with Ryan but he has disappeared. Larry,
the owner of OWC, would likely be the person to contact, but I've
not yet tried. My point is XPostFacto development seems to be
dead.
Sincerely,
Will Schoumaker
Thanks for writing, Will,
Ryan Rempel has been good enough to make
XPostFacto an open source project, so even in his absence it should
be possible for the project to continue moving forward.
I suspect there hasn't been much development work
necessary once XPF 4.0 was working with Tiger, which was released
over two years ago. Once Leopard is available, I'm sure someone
will carry the torch and development of XPostFacto 5.0 will proceed
apace.
I've emailed Rempel about this. If I receive a
response, I'll post it in the mailbag.
Dan
Another OS X Install Tip
Charles Broderick says:
Hi Dan,
I thought this was well known, but apparently not.
The Lombard was designed to
only recognize 384 MB of RAM max. Therefore, problems appear to
ensue if you try to install OS's with more than this.
I regularly run 512 MB RAM in my Lombard. If I have to reinstall
Tiger or Panther, I would have to take out one of the RAM sticks,
otherwise it won't boot.
HTH,
Charles
Charles,
Thanks for the info. I'll update the Lombard
profile on Low End Mac to reflect this.
Dan
Dan Knight has been publishing Low
End Mac since April 1997. Mailbag columns come from email responses to his Mac Musings, Mac Daniel, Online Tech Journal, and other columns on the site.
