      Firmware Update Process For DM-5024

                               NOTE
     Texel does not encourage it's customers to perform this procedure.  The
     contents of the DM-5024 are extremely sensitive and may be damaged. 
     Therefore, if the person performing this procedure feels confident of their
     expertise to perform this upgrade they must also feel confident that they can
     repair the drive if any damage occurs.  In short, you break it, you fix it!!! 

                         
                         Rick Horwitz, Texel


1.  The external plastic case used by the DM-5024 is retained to the chassis
    sled using four retaining tabs located at the rear of the case (Refer to
    illustration 1).  Two of these retainers are located on the top left and top
    right portions of the case.  The remaining two are located on the bottom left
    and bottom right portions of the case.  Please note that these tabs are all
    approximately one inch from each corner.  Only the bottom two tabs are
    visible.

    To remove the outside plastic enclosure, spread open the bottom and top
    portions of the rear cover.  This can be accomplished using two wide, flat
    bladed screwdrivers.  Ensure that the screwdrivers are placed at the mid
    section of the rear panel. 

    Apply even pressure on the CD-ROM drive front bezel so that the chassis
    can slide out pass the retainer tabs.  The pressure on the drive bezel should
    not be applied directly on the access door. 

                        -CAUTION-
   The sheet metal on the chassis may have sharp edges. 

   Once the chassis is completely removed from the case perform the following procedures:

2.   Remove the RFI sheet metal shroud located at the rear of the CD-ROM
     drive.  Only one screw secures this sheet metal shield.  The opposite side
     of the shroud is secured by a tab inserted into to a recess on the chassis. 
     In order to remove the shroud, it must be lifted directly upwards.  Refer to
     illustration 2 on the attachment.3.Remove the audio interface cable.  This is best accomplished by grasping
     the connector and removing.  This method prevents the wires from being
     over-stressed during the removal process. 

4.   Remove the 50 pin flat ribbon cable.  The preferred method is by grasping
     both corners of the cable and removing straight and evenly outward.  This
     prevents damage to the pins.

5.   Remove the switch interface connector.  There are two basic types of these
     connectors currently in use.  One type uses a small PCB with a DIP socket. 
     With this type, the PCB must be removed by applying vertical force on the
     PCB.  The PCB must to moved evenly so that the pins on the Drive PCB
     are not bent or broken.

    If the drive uses a standard IDC connector, the connector is removed by
    pulling horizontally straight outward.

6.   Remove the Molex Power Plug.  Again this is accomplished by pulling the
     plug horizontally outward.

7.   Using a flat blade razor, carefully peel back the plastic dust cover on both
     sides.  Be sure not to touch the adhesive side of the wrapper.

8.   Using a Phillips head screwdriver, remove all four machine screws on top
     of the drive.

                          -NOTE-
  The next steps that follow require the use of a Anti-Static
  device worn on the wrist and grounded to earth.  This device
  is commonly refered to as a Wrist Stat.

9.   Lift the CD-ROM drive cover completely off.  The cover must be
     maintained horizontal while removing.

10.  With the PCB exposed, and the assembly front facing toward you, raise the
     PCB from the right side to expose the component side.  In some cases the
     board may be stuck to one of the mounting screw holes.  If so, use a small
     flat bladed screwdriver to pry the board loose. DO NOT BEND THE
     PCB!!!

11.  With a flat bladed screwdriver lift out the existing EPROM.  The proper
     method for this removal is to lift up one side of the EPROM by about 2
     mm,  then do the same for the opposite side.  Continue this action until the
     EPROM is completely removed. 

12.  Insert the new EPROM.  In some instances these new EPROMS must have
     their legs formed to match the PCB socket.  While inserting the new
     EPROM ensure that no pins are bent or broken.
 
13.  Carefully flip the PCB back onto the CD-ROM chassis.

14.  Place the sheet metal cover back on the drive.  Observe the elongated
     flange on the left side.  This flange has a 1 mm recess that retains itself to
     the drive chassis.  This must be fully inserted into the chassis.  Please use
     caution to ensure that no wires are pinched. 

15.  Re-secure the top cover using the four exist machine screws.

16.  Place the dust cover wrapping back on the cover of the drive.

17.  Replace all connectors removed in steps 3, 4, and 5. all applicable
     precautions in for these steps apply.

18.  Replace the RFI sheet metal shroud.  Ensure that the retainer tab is fully
     seated into the chassis.  Replace the remaining machine screw.

                     -CAUTION-
   The sheet metal on the chassis may have sharp edges. 

19.  Slide plastic case over the chassis.  The upper rear flange of this cover may
     have to be lifted slightly in order to slide the remaining portion of the
     chassis in place.

20.  The refit procedure is now complete. 


