TechTails Archives

Subject: Tech Tails #52: G4 Power Problems
Date: January 29th, 2001

Hello everyone,

My name is Jerry. I'm one of the techs here at Small Dog. I will be
contributing to Tech Tails, so you should see a newsletter from me once a
month from now on. 

I've been using an Apple since my parents bought me my first computer at the
age of 11. It was an Apple IIc, if you remember those. No hard drive; you
loaded the operating system from 5.25 floppy. I had a few games, a nifty
9-inch black-and-white screen, and the original ImageWriter dot-matrix
printer. I think the whole thing cost around $4000 in 1983 or 1984. Ahhh, to
be young and a computer geek. Well, things have come a long way since then.

It's strange to remember what it was like to be a kid during the start of
all of this stuff: the G4, the $100 ink-jet that blows my old ImageWriter
out of the water, the Sony PlayStation 2, virtual gaming that is starting
to  rival reality, the new Titanium PowerBook!!! I had an Atari. I would
play PacMan and Space Invaders for hours and hours. One of my buddies had a
Kalekovision (sp?) and another had a Commodore 64. We had all of the world's
home-gaming technology at our disposal. Let it suffice to say that we still
spent lots of time playing ball and bottlecaps. Nowadays, a kid could be
sitting on a beach, playing Tomb Raider or Diablo on his new G4 Titanium
PowerBook wirelessly via a cellphone modem connection with some other kid
in Russia. It's a long way and it's amazing.

+-----------------------------------------------------------------------+

G4 FRONT PANEL BOARD ISSUE

I'd like to talk about an issue with G4 towers that affects all models of G4
(PCI, AGP, Gigabit, and Digital Audio), although failure rates are low.
Through my search of Apple's Technical Information Library and like
resources, I found mention of an intermittent power issue that I have seen
in one out of every 100 machines.

According to Apple, some G4 units don't power on when you press the button
on the front of the machine. Their suggested fix is to check the seating of
the cables that go into and come out of the front panel board - the board
that sits right behind the power button on the front of your machine. I have
found that the problem can manifest itself in a few other ways, too.

It can cause random power-up and power-down problems, meaning that you may
have problems shutting down or starting up your Mac. You may also have
problems keeping it powered up once started or powered down once shut off.
I've seen it cause a "no-wake-from-sleep" issue in a few machines. I've even
seen it blow logic boards.

The problem has to do with a bad front panel board. Sometimes the wiring
becomes compromised, and sometimes it is a faulty circuit board. Whatever
the case, when it goes bad, your machine may act like it is possessed. You
try to start the machine up from the button on the front of the unit and get
nothing - completely dead. Sometimes you'll hear a little "pop." The machine
may power itself on in the middle of the night or shut itself off in the
middle of a big project. Once, I even had a unit that would pretend to start
up, and then a burning electrical smell would issue from the logic board,
and then smoke! All of these symptoms can be caused by the same problem: a
bad front panel board.

Some of the testing procedures I can suggest for troubleshooting this weird
power issue (other than checking the seating of the front panel board cable)
are:

1) Verify the that the voltage switch on the power supply is set to the
correct voltage (115 for the US).

2) Unplug all peripheral devices (SCSI, FireWire, USB - including your
keyboard and mouse).

3) Verify that the power cord you are using is good and is plugged into a
working power source, then reset the PMU. Resetting the PMU requires
unplugging your machine and quickly pressing the small black button on the
back left-hand corner of your logic board (near the on-board battery).

Of course, if you have a no-power issue, with a bad front panel board and no
keyboard attached (or one of the Pro types), you will not be able to power
up your machine at all. If you have one of new Apple Pro keyboards, it's a
good idea to also have one of the older compact iMac-style keyboards. You
can get one in graphite to match your machine, or any of the assorted iMac
colors. With the power button on these keyboards, you may be able to power
up your G4 even if it has a bad front panel board. These keyboards were
rumored to not work with the newer G4s, they have worked with all the G4s
I've tested (including the new Digital Audio models).
  
Other than what I have suggested so far, the only thing you can do to test
this failure is to replace the suspect front panel board with a known good
one from a working G4. Unfortunately, the boards are not all alike. The PCI,
AGP, and Gigabit models all have different front panel boards, so they need
to be exchanged like-for-like. DO NOT put the front panel board from a
Gigabit G4 into a PCI or AGP G4, or vice versa. You run the risk of damaging
your machine. Gigabit G4s and the new line (digital audio) are the same. If
you determine that you have a bad front panel board, hopefully your machine
is still under warranty. If not, the tiny 3-inch-square board will set you
back $200.

To summarize: If you have ANY weird power issues with your G4, you may have
a problem with your front panel board. The first things you want to do are:
examine the voltage switch on your power supply, make sure you're using a
known-good power cord, unplug all devices attached to your tower, and reset
the PMU. If the power issue persists, you should examine the front panel
board. First, reseat the cable that goes into the front panel board as well
as the other end that plugs into the logic board. If that doesn't solve your
problem, you may want to exchange the suspect board with a known-good one
from a G4 with the exact same board. As always, plug and unplug cables and
cords and flip switches while your machine is off.

+-----------------------------------------------------------------------+

SPECIALS

Here are a few specials - some exclusive to Tech Tales - valid through
2/04/00. Please use the wags for on-line orders or request the special
pricing if ordering by e-mail or phone.

+----------------------------------+

Replacement Apple FDHD Floppy Drives Auto Insert - $79

    To order: http://smalldog.com/?wag=4222

+----------------------------------+

Epson Factory-Refurbished Stylus Scan 2500 - $229!

Flatbed scanner, color printer, and copier all in one compact machine!

    To order: http://smalldog.com/?wag=96

+----------------------------------+

FACTORY-REFURBISHED iMACS

+---------------+

iMac DV 400MHz in Lime (older-style keyboard and mouse but has DVD-ROM):

iMac DV Lime 400MHz 64/10gb/DVD/FireWire w/128MB RAM Upgrade - $829!

    To order: http://smalldog.com/?wag=216

+---------------+

iMac DV 400MHz in Ruby (Apple Pro keyboard and mouse but has CD-ROM):

iMac DV 400MHz in Ruby 64/10gb/CD/FireWire w/128MB RAM Upgrade - $829!

    To order: http://smalldog.com/?wag=72

+---------------+

iMac DV+ in Sage, Ruby, or Indigo:

iMac DV+ 450 64/20gb/DVD/56k INDIGO with 3-Year AppleCare Protection Plan
- $1059!

    To order: http://smalldog.com/?wag=22

iMac DV+ 450 64/20gb/DVD/56k SAGE with 3-Year AppleCare Protection Plan
- $1059!

    To order: http://smalldog.com/?wag=92

iMac DV+ 450 64/20gb/DVD/56k RUBY with Epson Stylus Scan 2500 refurb
scanner/copier/printer - $1195!

    To order: http://smalldog.com/?wag=872

+---------------+

iMac DV Special Edition 500MHz in Snow or Graphite with 3-Year AppleCare
Protection Plan - $1199!

Get two more years of warranty than on a new machine and save a hundred
bucks to boot!

iMac DV/500 Special 128/30gb/DVD/56k SNOW w/3-Year AppleCare Protection Plan
- $1199

    To order: http://smalldog.com/?wag=467

iMac DV/500 Special 128/30gb/DVD/56k GRAPHITE w/3-Year AppleCare Protection
Plan - $1199

    To order: http://smalldog.com/?wag=545

+--------------------------------+

FACTORY-REFURBISHED iBOOKS

iBook Blueberry G3/300 32/3gb/CD/56K w/ 64MB RAM upgrade - $1149!

    To order: http://smalldog.com/?wag=90

iBook Tangerine G3/300 32/3gb/CD/56K w/ 64MB RAM upgrade - $1149!

    To order: http://smalldog.com/?wag=882

iBook Blueberry G3/300 64/6gb/CD/56k w/FREE Backpack - $1149!

    To order: http://smalldog.com/?wag=873

iBook Indigo G3/366 64/10gb/CD/56k/FireWire w/ FREE 64MB RAM Upgrade - $1299

    To order: http://smalldog.com/?wag=5498

iBook G3/366 Special Edition Graphite 64/6gb/CD/56k w/FREE PowerBook
BackPack - $1099!

    To order: http://smalldog.com/?wag=794

+-----------------------------------------------------------------------+

If you have any questions about the procedures I have described here, or
want to discuss other issue or perhaps future topics for my version of the
Tech Tails newsletter, please contact me at: Jerry@smalldog.com. Or, you can
reach me at (802) 496-7171, extension 26 (Mon-Fri 9am-6pm EST).

Jerry Dell'Orto
Jerry@smalldog.com

+-----------------------------------------------------------------------+
You are subscribed to Tech Tails, our tech tips e-mail newsletter from
Small Dog Electronics.  If you would like to be removed from  this  list:
Send  ANY  e-mail  message  to:          tech-off@list.smalldog.com
To add yourself, send ANY e-mail to:      tech-on@list.smalldog.com
If you  need  additional  help, please contact: ListMaster@smalldog.com
+-----------------------------------------------------------------------+
Check out our other newsletters:
Kibbles&Bytes our main Mac Newsletter Kibbles&Bytes-on@list.smalldog.com
Eds Up! -- news/info for the Mac educator  academic-on@list.smalldog.com
+-----------------------------------------------------------------------+
    Small Dog Electronics           "High Technology for Low Prices"
        1673 Main Street, Waitsfield, Vermont 05673 USA
   Phone: 802-496-7171  Fax: 802-496-6257  e-mail: art@smalldog.com
                   http://www.smalldog.com
+-----------------------------------------------------------------------+
Entire contents Copyright 2001 Small Dog Electronics, Inc., Waitsfield,
Vermont USA - All Rights Reserved

V 10.10.10.9