PG-M25XE (serv.man38). Intermittent start-up shut down (locks up) - Sharp Projector Technical Bulletin (repair manual). Page 2

LV064

Sharp Electronics (UK) Ltd., Technical Services Group

POWER UNIT MODIFICATION PROCEDURE

Tools required:
Extension cable (QCNW-A295WJZZ : SERVICE JIG)
Procedure:
1.  Referring to the service manual, remove the top cabinet.

• Take care not to break the tab (next to the lens).
• Take care not to break the speaker wire when disconnecting it from the socket.

2.  Referring to the service manual, remove the PC I/F unit.

• Disconnect the FPC from the socket SC8001 (81 pins).

3.  Referring to the service manual, remove the cooling fan (for power).

• Disconnect the connector from the socket P3101(3 pins).

4.  Disconnect the EA connector (13 pins) between the PFC unit and the input unit.
5.  Remove the PFC unit.

• Remove the four lock screws.
• Disconnect the connectors CN7004 (thermal fuse), CN7003 (LF-sw), CN702 (PL),

CN7103 (power unit) and CN7104 (power unit).

6.  Remove the power unit.

• Remove the three lock screws.

7.  Add a 100 k ohm resistor (VRS-CY1JF104J) in parallel to R7421. (See the below

figure.)

Note: Make sure that it has no solder bridge and dry-joint etc.
8. Connect the connectors CN7004, CN7003, CN702, CN7103 and CN7104.
9.  Using the extension cable (QCNW-A295WJZZ), connect the EA socket between the

PFC unit and the input unit. Note: Insulate all the cabinets not to touch the power unit
during adjustment.

10.Connect the AC cord to the connector CN701 of the PFC unit.
Note: Make sure that an image is projected.
11. Adjust the voltage of 2.5V line to 2.62±0.02V with VR7401. (See the below figure.)

• Measuring point of 2.5V line: Pin 9 (or 10) of the EA socket.
• GND : Pin 11 of the EA socket
Then, make sure that the voltage of 3.3V line is within 3.4±0.1V at the pin 12 (or 13) of
the EA socket.

12. Turn off the power and then disconnect the extension cable.
13. Referring to the service manual, re-assemble the power unit and the PFC unit.

Figure: