Troubleshooting The System - Infinity MODULUS Service Manual

Modulus
TROUBLESHOOTING THE MODULUS SUBWOOFER SYSTEM (IF999912 B/W)
I BLOWS LINE FUSE IN CABINET IMMEDIATELY
Usually: Short in toroidal transformer (power supply)
Could be: Short in amplifier
Could be: Voltage selector switch in wrong position
II BLOWS LINE FUSE IN CABINET AFTER SHORT PERIOD OF TIME, PLAYING MUSIC
Usually: Defective amplifier
III BLOWS LINE FUSE IN ECU
Usually: Defective ECU
Could be: Voltage selector switch in wrong position
IV BOTH LED's DO NOT LIGHT ON ECU
Usually: Defective ECU
Could be: Blown ECU line fuse or defective power cord
Could be: Lacking AC power source to line cord
Could be: Voltage selector switch in wrong position
V POWER LED (RED) O.K.; GREEN LED DOES NOT LIGHT ON ECU
Must be: Defective ECU
VI ALL LED's NORMAL, (cabinet LED goes off after delay) BUT NO OUTPUT
Usually: Defective amplifier
Could be: Defective ECU
Could be: Defective control cable
VII FRONT CABINET LED DOES NOT LIGHT (with ECU off or disconnected)
Usually: Defective amplifier
Could be: Defective toroidal transformer (power supply)
Could be: Blown line fuse
VIII FRONT CABINET LED DOES NOT GO OFF WITH ECU ACTIVE, AFTER DELAY (and no output)
Could be: Defective ECU
Could be: Defective amplifier
Could be: Defective control cable
IX BOTH CABINET LED's (front and power supply) DO NOT LIGHT (and no output)
Usually: Lacking AC power source to line cord
Could be: Voltage selector switch in wrong position
X VERY LOW OUTPUT (with ECU gain full clockwise)
Usually: Defective amplifier
Could be: Defective ECU
Could be: Defective control cable
Could be: Volume control on receiver turned down
XI WOOFER SQUEAL/OSCILLATION, "BREATHING", "THUMPING", OR EXCESSIVE EXCURSION
Usually: Defective control woofer
Could be: Defective amplifier
Could be: Defective ECU
Could be: Defective control cable
XII HUM FROM WOOFER WHEN ACTIVE
Could be: Defective amplifier
Could be: Defective ECU
Could be: Defective control cable
Could be: Defective (customer) signal input cable to ECU
Could be: Ground loop problem requiring 3 to 2 prong "cheater" plug on power cord
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