Verify the type of cable that is connected the StyleWriter II. Make sure that it is an Apple System Peripheral 8 cable (M0197LL/B) or compatible as described in the StyleWriter II manual. When a network cable, such as a PhoneNet or LocalTalk RJ11 Connector, is connected to the printer the symptoms you mentioned appear.
To verify the problem is cable related follow these steps:
1. Turn the printer off.
2. Unplug the printer cable.
3. Press and hold down the printer power button until the yellow light turns off.
The printer should print a self-test. If it prints the self test, the problem was cable related. If the StyleWriter II does not print a self-test with the cables disconnected, have the printer looked at by an Authorized Apple Service Provider.