Appendix G: Troubleshooting - Classe Audio Delta Series Service Manual

Appendix G: Troubleshooting

Symptom
DC offset of about 30mV
Ch 2 heatsink not on
IR not working
Current calibration impossible
Bias drifts, hard to stablize
Software misbehaving
Ground noise when input
disconnected or unterminated
Popping on warm-start (25s +) 100uF instead of 10uF on main boards
AC current reading 0A on idle
AC current reading 0A w/ load Solder bridge between pins 3-4 on U1 on AC-control board
Sensor board smokes 4.7
Intermittent: smokes 4.7 and
huge DC out
AC control calibration goes off
by 10V when switched to 230V
AC control reads 0.255 A
(intermittent)
Volume encoder not working
Appendix H: Main board tolerance voltage
Voltage across R140-R141
Voltage on R140-R141 (Ref. Gnd)
R140/R141 Values (ohms)
CA(P)2100 AMP Service Manual v1.4 inc voltage change info .doc
Main plug-in (amp) board, transistor Q111, pins 1 and 2 not reversed
5-pin cable on AUX PS not pin-to-pin (reverse)
R105 on IR board not changed to 200 ohms
Reversed trimpots on sensor/control board (B3B1XR04)
Temperature compensation transistor (Q9) not well glued on heatsink
Missing connection from IR to COMM boards
Loose or missing screws on RS-232 connector of comm. board
No bias
Bad via on sensor board, O/P relay control signal interrupted
Solder bridge on main board (pins 5-6 of K389 FET)
Wrong value trimpot on AC-control board
Bad connection on add-on (mod) electrolytic 10uF/35V cap
GUI board: PIC (U22) dead, possibly because power was accidentally
applied to this IC (cable to P4 swapped with one to P8)
Rails Voltage
Calculated Current (A)
Possible cause
CA/CAP-2100 CA-22/32/5200
66
12
54.00
412
0.0291
Revisions affected
B3B6XR03, XR02, XR01, XR00
Production problem (CA5200)
B3BAXR00/01
Production problem
Production problem
Production problem
Production problem
Mod on XR03, standard on 04
Production problem
Production problem
PCB manufacture problem
PCB stuffing problem
PCB stuffing problem
B3B3XR02 or older
B42AXR03 and future revs
CA-M400
84
12 7.4
72.00 52.60
665 200
0.0180 0.0370
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