Toshiba M200-ST2002 Maintenance Manual - Page 90

2 Troubleshooting Procedures 2.15 Wireless LAN Troubleshooting Procedure 3 Antenna Check Use an antenna test cable to check the antennas' connection. Follow the steps below. Any of the connections may be disconnected. Disassemble the computer following the steps described in Chapter 4, perform the following checks 1. Disassemble the computer and disconnect the wireless LAN antennas (white and black) from the wireless LAN board. Refer to Chapter 4, Replacement Procedures, for detailed steps of disassembling 2. Connect the tester set up for impedance measurement to the antenna jig. Measure the white antenna's resistance 3. Determine the resistance. The antenna passes the test when the resistance is 5Ω or less. If it is more than 5Ω, the antenna is faulty. 4. Measure the black antenna's resistance. Check if there is faulty. Figure 2-3 Antenna Test jig Measurement Value Pass/fail Comment 5Ω or less Pass Include cable loss More than 5Ω Fail The digital tester shows 0L ,etc. if there is a broken wire. NOTE: 1. The resistances determined with the steps above may not be stable according to the length of the antenna. The impedance of the antenna itself is about 0.5 to 0.8 ohm. 2. The above steps cannot accurately determine the impedance of the antenna. Use an LC meter for a precise measure of impedance. If each wireless antenna passes the above test, return the Wireless LAN module back, then perform Procedure 1. If the wireless LAN has still an error, go to Procedure 4. 2-52 Portege M200 Maintenance Manual (960-457)