wiki:Hardware/bDomains/bOutdoor/HTCEvo4G
HTC Evo 4G (model: PC36100)
Chassis Manager (CM) Connector

The CM connector is a standard 3x2 0.100" header. It is located on the back of the phone above the rear camera lens. Pin 1 is in the upper left corner. Refer to Table 1 for connector pinout.

Pin Function
1 Power - ground
2 Power - signal
3 Volume Up - signal
4 Volume Up - signal
5 Volume Down - ground
6 Volume Down - signal

Table 1: CM Connector Pinout



Figure 1: CM Connector

Chassis Manager (CM) Compatibility Modification

NOTE: All steps assume a device orientation where the "top" is the edge of the phone with the headphone jack, and the "bottom" is the edge with the USB and HDMI ports.


Phone Disassembly:

  1. Pry off back cover starting at the top.
  2. Remove battery.
  3. Unlock and remove SD Card.
  4. Remove 6x T-5 Torx screws.
  5. Separate the front and back of the phone by prying them apart along the edge (the black border around the red is part of the back half).


Adding CM Connector:

  1. Remove 1x Phillips screw in the top left of the PCB (by headphone jack).
  2. Gently lift the PCB from the right side using the cables on the left as a "hinge" until the PCB is at 90 degrees to the screen.
  3. Locate the power button on the under side of the PCB. It is at the top nearest the notch in the PCB (see Figure 2).
  4. Solder 2 wires to the power button pads nearest the notch in the PCB. Looking at the power button, the top-right pad is ground, the bottom-right pad is the signal.
  5. Place the PCB back down against the screen and reattach the screw removed in step 1.
  6. Locate the Volume Up button on the right edge of the PCB (see Figure 2). It is just above the orange ribbon cable.
  7. Solder 2 wires to the top 2 pads. The top-left pad is ground, the top-right pad is the signal.
  8. Locate the Volume Down button on the right edge of the PCB (see Figure 2). It is just below the orange ribbon cable.
  9. Solder 2 wires to the top 2 pads. The top-left pad is ground, the top-right pad is the signal.
  10. Route all wires to the area just above the rear camera (use hot glue or tape as needed).
  11. Solder the wires to a 3x2 0.100" header as described in the Table 1 CM Connector Pinout.
  12. Hot glue the CM Connector to the PCB.
  13. Cut/drill a hole in the red half of the phone as in Figure 3.
  14. Looking at the underside of the read half:
    1. Discard the black rubber gasket around the speaker on the red half of the phone (see Figure 4).
    2. Cut off the 0.5cm tab at the bottom of the top-right screw hole.
  15. Cut/drill a hole in the black back cover of the phone as in Figure 3.
  16. Reassemble the phone by following the reverse of the disassembly steps above.
Figure 2 Figure 3 Figure 4


Testing CM Connector:

  1. Short pins 1-2 momentarily, the phone should start booting up.
  2. Once the phone boots up, unlock it to the home screen.
  3. Short ping 3-4 momentarily, the screen should indicate volume being increased.
  4. Short pins 5-6 momentarily, the screen should indicate volume being decreased.
  5. As a final step, test the power and volume up/down buttons themselves.
Last modified 2 years ago Last modified on 07/20/15 15:53:08

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