Toshiba Portege M200 Maintenance Manual page 90

2 Troubleshooting Procedures
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.
Measurement Value
5Ω or less
More than 5Ω
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
Figure 2-3 Antenna Test jig
Pass/fail Comment
Pass Include cable loss
Fail The digital tester shows 0L ,etc. if there is a broken wire.
2.15 Wireless LAN Troubleshooting
Portege M200 Maintenance Manual (960-457)