Cap2100; Testing The Input Board (B3F1Xr04); Testing The Aux Power Supply Board (B3F2Xr04) - Classe Audio Delta Series Service Manual

Bring up the AC gradually (in 15V steps) while measuring the main DC rails at +V201 and –V201 relative to ground
at GND201. Keep a close eye on the circuits, listen for frying or popping noises, and feel the variac for vibration
caused by excess current. If you hear a capacitor pop, mark the board and replace it. Raise the variac voltage until
you measure +/-66Vdc on the DC voltage rails (about 70Vac on the variac, depending on the transformer on the
jig).
Now do the same thing to other side of the board.
Connect the secondary of transformer to AC1 and AC3 and Center Tap at AC5.
Bring up the AC gradually (in 15V steps) while measuring the main DC rails at +V101 and –V101 relative to ground
at GND101. Keep a close eye on the circuits, listen for frying or popping noises, and feel the variac for vibration
caused by excess current. If you hear a capacitor pop, mark the board and replace it. Raise the variac voltage until
you measure +/-66Vdc on the DC voltage rails (about 70Vac on the variac, depending on the transformer on the
jig).
Disconnect the capacitor board and discharge the capacitors.

CAP2100:

Testing the Input Board (B3F1XR04)

Perform a detailed visual inspection of the board. Check all capacitor directions (polarity). Verify that all the
modifications have been implemented (see Appendix F).
Connect the Input board to the test jig and verify the following voltages:
Before regulator Q101 (one side of diode D101): about 17Vdc
After regulator Q101 (other side of diode D101): 12Vdc
Before regulator Q102 (pin3): 12Vdc
After regulator Q102 (pin1): 5.8Vdc
Set the volume to 86 (unity gain). Pass a 1Vpeak, 1kHz signal (sine-wave, then square wave) through ALL the inputs
(both left and right: BAL, LIN1, LIN2, LIN3, and TAPE-IN) and check that it appears on ALL the outputs (both left and
right: LINout and TAPEout). In each case repeat with 10Hz and 10kHz signals and make sure the output levels are the
same as the input level and the same for all frequencies. Verify that the square wave signal shows no signs of ringing,
oscillation, or other deformation.
With the volume still at 86 confirm that the DC offsets on the Line and Tape outputs do not exceed +/-4mV.

Testing the AUX Power supply Board (B3F2XR04)

Perform a detailed visual inspection of the Aux Power Supply. Check all capacitor directions (polarity).
Connect AUX transformer (TC0600-0040) to U101.
Verify the following voltages:
Before regulator Q201 (right side of diode D201) about 17.5Vdc
After regulator Q201 (left side of diode D201) 12Vdc.
Before regulator Q101 (right side of diode D101) about 17.5Vdc
After regulator Q101 (left side of diode D101) 12Vdc.
CA(P)2100 AMP Service Manual v1.4 inc voltage change info .doc Page 10 of 50