Alesis CoolFire 15 Service Manual page 9

HEADPHONES jack. Set EFFECT to LO MID, rotate VALUE knob output should change accordingly.
2.7 HI MID Performing mode testing: connect musical signal to INPUT jack, insert earphone connector to
HEADPHONES jack. Set EFFECT to HI MID, rotate VALUE knob output should change accordingly.
2.8 HIGH Performing mode testing: connect musical signal to INPUT jack, insert earphone connector to
HEADPHONES jack. Set EFFECT to HIGH, rotate VALUE knob output should change accordingly.
2.9 EDEG Performing mode testing: connect musical signal to INPUT jack, insert earphone connector to
HEADPHONES jack. Set EFFECT to EDEG, rotate VALUE knob output should change accordingly.
2.10.HUM CANCEL Performing mode: Set EFFECT knob to HUM CANCEL, rotate VALUE and verify the
display shows match with performing modes.
2.11. NOISE GATE Performing mode: Set EFFECT to NOISE GATE, rotate VALUE and verify the display
shows match with performing modes.
2.12. FX1 Performing mode: Set EFFECT to FX1, rotate VALUE and verify the display shows match with
performing modes.
2.13. FX2 Performing mode: Set EFFECT to FX2, rotate VALUE and verify the display shows match with
performing modes.
2.14. LEVEL Performing mode: connect musical signal to INPUT jack, insert earphone to EARPHONE jack,
clockwise rotate VALUE knob, verify volume increase, counterclockwise rotate VALUE knob, verify volume
decrease.
3. store and power lost protection:
Set "EFFECT" knob to "COMP/LIMIT" position. Rotate "VALUE" knob until the display shows "C1", press
"VALUE" knob, display flashes. Rotate "VALUE" knob, make it displays "A0", press "VALUE" knob again.
After above procedures was done. Set "EFFECT" knob to "PLAY" "A0" status, turn off power, after 3 seconds
later, turn on the unit. The display shows "A0", rotate "EFFECT" knob to "COMP/LIMIT" position, verify the
display shows "C1".
7. "HEADPHONES" jack testing:
① input sensitivity: input 1KHZ/-25dB sine wave, left/right channel output range 40mW±2mW.
② THD+N: 1%±0.01( when THD @1% output power over40mW)
③ RESIDUAL NOISE: ≤0.2mv±0.1mv （set to MUTE, FILTERFREQ：20KHz)
④ Output Frequency Respond: 73HZ~3.48KHz/-3dB
⑤ Plug/unplug "HEADPHONS" no pop noise.
AMP board
note: if no special specification, all testing under below condition.
A: from "AUX INPUT" RCA input signal.
B: from "SPEAKER OUT" jack output signal, load 8ohm/100w resistor.
1. "FOOT SWITCH" jack testing:
plug in standard footswitch to "up" and "down", verify if can function as the Program Up and Program
Down buttons.
2. "EXPRESSION INPUT" jack: Connects to a B50K potentiometer (details connection please refer to the
illustration.), set to "LEVEL" Performing mode "Pd" status. Connect musical signal to "INPUT" jack,
connect headphone to "HEADPHONES", when clockwise rotate potentiometer to maximum, measure
potentiometer pin 1.2.3, the DC voltage should be: 1.65V, 2.04V, 2.0V, as well as the volume increase; when
counterclockwise rotate potentiometer to minimum, measure potentiometer pin 1.2.3, the DC voltage should
be:1.65V, 1.65V, 2V, as well volume decrease.