JBL PowerBass PB10, Service Manual

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PB10
24
PB10 Testing Procedure (Cont.) (Revision 1 Only)
- Voltage measurements
OP AMP
U1(7) U2(7) U1(1) U2(1) U1(14) U2(14) U2(8) PU1(14) PU1(8)
SPEAKER
O/P
180mV 266mV 325mV 404mV 451mV 451mV 1.33V 6.37V 5.72V 15.3V
2. High Level Input Sensitivity
-Set up Turn level, Lo Pass Pot Fully CW and LFE switch off
Set Generator at 1.09V@50Hz
Signal to High level input
-Voltage measurements 15.3V at speaker output
3. Low-Pass
-Set up Set Generator at 100 mV@100Hz
Signal to Low level input
Measure voltage at speaker output
-Voltage measurement
Low-Pass Pot Setting Output
CW 11.4V
CCW 2.19V
4. LFE
-Set up Set Generator at 100mV@200Hz
Signal to Low level input
Measure voltage at speaker output
LFE switch Setting Output
OFF 2.96V
ON 8.40V
See flow chart next page for diagnostics.