Troubleshooting - ADC Sound Shaper Three Service Manual

TROUBLESHOOTI NG
SYMPTOM
CAUSE/REMEDY
1) No output
1) Faulty AC power cord
*Replace the cord.
2) Defective power switch
"Replace the switch.
3) Broken wire in the power transformer (Tl00l)
*Replace the transformer.
4) Check Fuse, European and PX only.
2) Power indicator LED does not
1) Defective LED Dl00l
light.
*Replace the LED.
2) Open in the power transformer secondary winding
*Replace the transformer.
3) Check Fuse, European and PX only.
3) Power indicator lights but no 1) Defective diode D702 and/or D703
output.
"Replace the diode{s).
2) Defective transistor TR701 and/or TR702
*Replace the transistor{s).
4) No output with test signal
1) Defective transistor TR 101-116
appl ied to the input terminals.
*Replace the transistor{s).
2) Defective resistor or capacitor of Main Amp stage
*Replace the defective part{s).
5) "TAPE OUT" inoperative 1) Poor contact in "TAPE OUT" input jacks
*Repair or replace the jacks.
2) Faulty TAPE MONitor switch
*Repair or replace the switch.
6) "I NPUT" inoperative
1) Poor contact in "I NPUT" input jacks
*Repair or replace the jacks.
7) "OUTPUT" inoperative 1) Poor contact in "OUTPUT" output jacks
"Repair or replace the jacks.
8) "TAPE MONITOR" inoperative 1) Poor contact in "TAPE MONitor" input jack
*Repair or replace the jack.
2) Faulty "TAPE MONitor" switch
*Repair or replace the switch.
9) Frequency control 26/32/39 Hz
1) Faulty VR501/601
has no effect. *Repair or replace.
2) Defective R301 /401, 335/435, 336/436 or L301/401
*Replace the defective
0
parts.
10) Frequency control 47/56/68 Hz 1) Faulty VR502/602
has no effect.
*Repair or replace.
2) Defective R302/402, 303/403, 304/404, 337/437,338/438 or L302/402
"Replace,
11) Frequency control 84/100/120
1) Faulty VR503/603
Hz has no effect. *Repair or replace.
2) Defective R305/405, 306/406, 307/407, 339/439, 340/440 or L303/403
*Replace.
12) Frequency control 150/180/215 1) Faulty VR504/604
Hz has no effect. *Repair or replace.
2) Defective R308/408, 309/409, 310/410, 341/441, 342/442 or L304/404
*Replace.
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