Subject: Standard C508A mods


   top right-hand corner


            |     |          |
            |     |          +-----+
            |     |           o  o |
            |     |              # | <- remove this SM component
            +-----+           o  o |     for cellular RX unlock
                                   |
     |                             |
     |                             |
     |                    //        \
     |                   //          \
CPU  |                                \
     | o o                             |
     | o o         under              /
     | o#o        Lithium            /
     |            battery           /
-----+                             |
        ^                          |
        |                          |
     remove this SM (RD77)         |
     component to extend           |
    TX 115-164 & 400-464           |


The following procedure involves removing the 
lithium battery which saves your memory channels.
Note any memory channels you wish to save -- you
will have to re-enter them.  Also note the placement
of the battery before you remove it, since you don't
want to put it back in the wrong way.

Remove the 4 screws from the back of the radio and
separate the front and back pieces.  Be careful not
to damage the flexible cable connecting the two.
Unsolder and remove the lithium battery, being careful
not to short-circuit it.  Remove the surface mount 
chip resistor RD77, at the fifth pin of the CPU chip,
counting up from the bottom.  Two component pads
above it are already empty.  To permit RX of cellular,
also remove the surface mount component depicted in
the diagram above, way in the upper right-hand corner.
Resolder the lithium battery back into place, noting
that the polarity is correct.  Press the reset switch,
and reattach the two halves of the radio.  Place the
batteries back in and power on.

---------------------------------------------------------
From scottw@atlcom.net Mon Sep 30 14:48 MST 1996
Subject: Revision of modification  to model C-508A

Seperate radio halves, DO NOT desolder lithium battery, use wood carving
razor to remove SM.  Razor must be long, sharp and thin at which point
you can get up under the SM and pop off.  Remove SM's and press reset
button, reattach two halves.  Place batteries back in and power on.