Toshiba satellite A20 series Maintenance Manual page 103

2.11 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 antenna cables (white
and black) from the wireless LAN card. 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 less
than 5 ohm. If it is more than 5 ohm, the antenna is faulty.
4. Measure the black antenna's resistance. Check if there is a faulty.
Measurement Value
Less than 5Ω
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.
Satellite A20 Maintenance Manual (960-444)
Figure 2-3 Antenna Test jig
Pass/fail
Pass Include cable loss
Fail The digital tester shows 0L ,etc. if there is a broken wire.
2 Troubleshooting Procedures
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