Genius GM56USB Service Manual Download

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Service Manual

Chapter 4. Removal and Replacement

Step Description

Picture

1. Turn

over

modem

To disassemble the modem, you
have to turn over modem.

2. Loose screws Using screwdriver to loose screw.

3. Take

apart

rear flat

After taking screw off, you can take
up the upper cover

4. Take

apart

PCB

Now, You can take apart the PCB
from the lower cover.

The PCB is the most important part
of modem.

Version 1.0

Page 10

Summary of Contents for GM56USB

Page 1: ...Service Manual GM56USB MODEM...

Page 2: ...hapter 2 Testing Procedures 3 A Testing Flow Chart 3 B Check U1 Pin 1 5V 4 C Check U1 Pin 3 Data Clock 5 D Check X1 Working Frequency 6 E Check IC1 Pin 41 Reset Signal 7 F Check K4 Pin4 8 Chapter 3 Tr...

Page 3: ...RJ 11 cable USB Port USB Cable Speaker b Software Win98 above GM56USB Driver c Function Block USB ST7554 USB MODEM CONTROLLER TQFP48 7 7 1 4 MM STLC7550 Analog front end AFE TQFP48 7 7 1 4 MM CRYSTAL...

Page 4: ...edures A Testing Flow Chart Check U1 Pin 1 REPLACE U1 T T F F Check U1 Pin 3 T Check Working FR T Check IC1 Pin41 T F F F REPLACE K4 REPLACE C5 IC1 REPLACE K1 IC2 RESOLDER R8 R9 REPLACE U1 IC2 Check K...

Page 5: ...Service Manual B Check U1 Pin 1 5V U1 PIN 1 5V Version 1 0 Page 4...

Page 6: ...Service Manual C Check U1 Pin 3 Data Clock U1 PIN 3 Version 1 0 Page 5...

Page 7: ...Service Manual D Check X1 Working Frequency C10 X1 C16 IC2 Version 1 0 Page 6...

Page 8: ...Service Manual E Check IC1 Pin 41 Reset Signal IC1 Version 1 0 Page 7...

Page 9: ...Service Manual F Check K4 Pin4 K4 PIN4 Version 1 0 Page 8...

Page 10: ...ooting Guide Problems Probable Reasons Solutions 1 Dialing fail 1 PCB defect 1 Replace K4 2 Replace IC1 3 Replace IC2 1 Connection fail 1 PCB defect 1 Replace U1 2 Replace IC1 3 Replace IC2 4 Replace...

Page 11: ...mble the modem you have to turn over modem 2 Loose screws Using screwdriver to loose screw 3 Take apart rear flat After taking screw off you can take up the upper cover 4 Take apart PCB Now You can ta...

Page 12: ...Description Part number U1 USB6B1S08 K1309061 X1 9 216MZH K0809012 IC1 ST7550 K1309060 K4 K0917006 IC2 ST7554 K1309059 C16 27PF 0603 K1509048 C10 33PF 0603 K1509046 C5 0 1U 0603 K1509028 Chapter 6 To...