Table 2-I. Troubleshooting Checklist (continued)

Are the SCSIbus terminators correctly installed?

Both endsof the SCSIbus require termination. The terminator on the host adapter is installed at the factory. An external terminator is supplied for terminating the last device on the bus.

Does any device require a special SCSIterminator?

Does any peripheral device have an internal SCSI terminator?

Someexternal devicesmayhave peculiar termination requirements. The device manual should explain any special termination requirements and how to avoid problems.

Excessivetermination may causedamageto the transceiversof all the deviceson the bus, including the adapter card, or may causeunreliable operation. Check the device manuals to determine whether they have internal terminators and how to avoid overloading the bus.

Are all devicesthat can supply termination power configured to do so?

For optimum noise immunity, we recommend that devices be configured to supply TERMPWR when possible. If at least two devicessupply TERMPWR, locate them at each end of the SCSI bus, Additional devices that supply TERMPWR can be evenly distributed along the bus.

2-8 Service Information