Troubleshooting - Aiken Amplification Invader MKII User Manual

Troubleshooting

Pilot lamp not lit:
Is the amplifier plugged into a functional outlet of the appropriate voltage?
Is the mains fuse blown? If so, replace with the appropriately rated fuse. If the fuse
again blows, the amplifier may have a shorted output tube or rectifier tube. Replace the
tubes and fuse, and power the amplifier up again. If the fuse still blows, the amplifier will
need to be serviced.
Pilot lamp lit, but no sound:
Is the HT fuse blown? If so, replace with the appropriately rated fuse. If the fuse again
blows, the amplifier may have a shorted preamp tube, output tube or rectifier tube.
Replace the tubes and fuse, and power the amplifier up again. If the fuse still blows, the
amplifier will need to be serviced.
Is the speaker functional and plugged in correctly? Insure the amplifier's output
impedance selector is correctly set to match the speaker in use.
Is the guitar cord functional? Bypass any pedals and plug straight in with a known good
cable to test.
No reverb:
Are the reverb cables plugged into the tank (inside the bag at the bottom of combo
cabinets) and into the RCA jacks on the amplifier chassis?
If the amp or tank has been removed from the cabinet, the cables may have accidentally
been switched. Try reversing the leads that plug into the chassis jacks (the reverb tank
"IN" cable should go to the jack nearest the small reverb driver transformer, and the
reverb tank "OUT" should go to the other jack).
With the amplifier on, turn the reverb control mid way up and shake the tank - if the tank
makes a "crashing" noise through the speaker, the recovery side of the reverb circuit is
functional, and the problem is in the send side. If there is no noise, the problem is on the
recovery side. If it is on the recovery side, remove the tank from it's tolex isolation bag
and repeat the test to insure the reverb springs aren't inadvertently touching the bag.
If the problem is on the recovery side, try replacing the ECC83/12AX7 reverb recovery
tube. If the problem is on the send side, try replacing the ECC81/12AT7 reverb driver
tube. See the tube replacement section for locations of these two tubes.
Try replacing the cable on the bad side. If this doesn't fix the problem, try replacing the
reverb tank. If the problem still exists, the amplifier will need to be serviced.
InvaderMKIIManual.doc 12/08/11
Copyright 2003-2011, Aiken Amplification, Inc.
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