Test Procedures - Alesis MicroVerb Service Manual

6.4 C23
See Section 6.1 for details. If C23 is faulty, the unit will not have any effects out (no wet
signal).
6.5 C32
See Section 6.1 for details. If C32 is faulty the +5V rail will not be solid at the 4053 (U9). This
will manifest itself as a distorted wet signal.
6.6 Input/Mix/Output Potentiometers
Note that when replacing any of the 3 potentiometers due to "scratchiness", it's a good idea
to replace all 3 if possible. This is due to the fact that disassembly and subsequent reassembly can
cause the other potentiometers to fail in the same fashion. Also note that when replacing
potentiometers, it's a good idea to reattach the front panel before soldering any new potentiometers
in. This prevents damage to the potentiometers due to misalignment.
6.7 Goldstar 4053s (U9)
These devices have been found to be somewhat unreliable, and should be replaced. We are
currently using Phillips CD4053s as replacements. The failure of this device usually causes extreme
D.C. offset in the SAR output of the DAC.
6.8 Goldstar 7404s (U11)
These devices have been found to be somewhat unreliable, and should be replaced with TI
74HC14s. If this component fails it will cause small "Pops" to be heard when switching programs.
6.9 Beige Power Supply Jacks
These are older jacks and should be replaced with the newer black jacks (the older beige
types have a tendency to break the center pin).

7.0 Test Procedures

Testing the MC or C2 is extremely simple.
Use a clean audio source (CDs preferred) and set up the unit according to the user's manual.
Listen to the wet (effects) output for any distortion.
Be sure to move all of the potentiometers through the full range of their movement.
Listen for any dropouts which would indicate a scratchy potentiometer.
To ensure that the shaft encoders are functioning properly all programs should be listened to
briefly.
Turn the input level all the way down, and the output level all the up.
Listen for excessive noise in the noise floor.
As a final check it's a good idea to physically shake the unit so that no loose parts remain inside
the unit.
MicroVerb/MicroVerb II Service Manual 1.00 5 3/7/2003