Gateway Colorbook service notes

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I am writing this for the benefit of anyone else who ever needs this
information to work on an old Gateway Colorbook computer.  I could not
even find disassembly instructions for the Colorbook.

I have a Gateway Colorbook (CB4DX250 ... 486 DX/2 50MHz) that I keep
around for historical purposes (it's running DOS 6 and Windows for
Workgroups 3.11).  The CMOS battery has died (hey, it's 16 years old),
which, in this case, means that the computer won't even boot (you have
to go into setup every time and reset the hard drive parameters ... then
it will boot ... ONCE).

The CMOS battery is a Toshiba ER17330V, these are actually available but
they cost more than I paid for the laptop (and this battery is a custom
gateway part).

Ok, I wanted to fix this ... first task, open up the laptop.

To start, remove 6 self-tapping screws in the 4 corners plus the middle
of the left and right sides.  5 are hidden under rubber feet.  the 6th,
a corner screw, is in the battery compartment.

Next, remove three more screws in the battery compartment.  Two are
along the compartment edge towards the center of the laptop, one is the
rearmost of a group of 3 screws near the rear middle of the compartment
(do not remove the other two screws in this group of 3).

There are two "snaps" that hold the keyboard bezel to the lower base at
the front of the laptop.  One is right over the mouse, one is right over
the floppy drive.  These are difficult to unsnap, be careful, but it can
be done.

At this point, you can separate the lid and keyboard bezel from the
lower base, there is one connector for the electrical wiring to the LCD
that unplugs easily.

I recommend that you don't disconnect the keyboard, it's tricky to get
it's flat flex cable reconnected.  The socket is a standard flex-cable
ZIF socket (if you don't know about those, you will probably destroy the
keyboard), but the cable is actually multi-flex cables that all get
stuffed into a single connector, and it's tricky to re-insert if you
remove it.

The battery is located between the trackball and floppy in it's own
plastic battery compartment.  Now I did something sleazy that worked:  I
replaced the battery with a standard lithium camera battery, CR2, that I
had lying around from my film camera days.

CAUTION:  DO NOT ***EVER*** attempt to solder wires directly to a
lithium battery.  It will explode violently and almost certainly injure

I first removed the wire and connector from the original dead battery.
You will need every mm of wire, and on the back (negative side, black
wire) of the old battery I actually removed the metal tab and plate that
was welded to the back of the battery.  I cut off the positive (red)
wire leaving as much wire as possible (like I said, you will need every
mm of wire).

I then formed a "contact" for the CR2's positive terminal by bending a
paper clip in an "S" shape just inside the plastic battery compartment,
and then I soldered the red wire from the old battery harness (with
connector at the other end) to the paper clip.  I inserted this terminal
into the laptop's CMOS battery compartment, then the battery, then a
piece of very high density foam rubber between the negative end of the
battery and the back end of the battery compartment (to keep pressure on
everything), and I wedged the battery terminal and plate (still
connected to the negative (black) wire of the harness with the connector
at the other end) between the foam and the back end of the battery.  I
reassembled everything and it works.  I stuck another piece of foam on
top of the battery (under the keyboard) to keep the CR2 battery in place.

The CR2 is 3.25 volts (or perhaps even a bit less), which is less than
the 3.6 volts of the original battery.  Also, it's much lower capacity
(the original battery is something like 1,700 mah, the CR2, which is
smaller in both length and diameter, is only 850 mah, so it probably
won't last nearly as long and will require periodic replacement.
However, it is working and the original batter was expected to last for
years and years, so "not as long" may still mean that it lasts for 1 to
5 years.  [The good news is that the CR2 was intended to charge the
flash capacitors in cameras and is rated for a max. 1 AMP drain, while
the laptop CMOS application probably draws only micro-amps (one
one-millionth of an amp).  Again, while admittedly lower in capacity, it
may still last for years.]

Barry Watzman

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