Aux Power Supplies And Capacitor Boards; Ca2100; Testing The Aux Power Supply Board (B3A5Xr02); Testing Capacitor Board (B3A1Xr00) - Classe Audio Delta Series Service Manual

Aux Power Supplies and Capacitor Boards

CA2100:

Testing the AUX Power supply Board (B3A5XR02)

Perform a detailed visual inspection of the Aux Power Supply. Check all capacitor directions (polarity). Check if all
capacitors are standing up properly. Verify (measure if necessary) that the Voltage Selector (CON1) resistors are:
0 ohms for the 100Vac setting,
75 ohms for the 120Vac setting,
182 ohms for the 230Vac setting,
511 ohms for the 240Vac setting.
Use your multimeter on its diode setting to verify that all four voltage-select LEDs as well as the "bad_power" LED are
installed with the correct polarity and are working (each LED should light-up). You will have to move the voltage-select
jumper to all four positions to check this.
Verify jumper setting for 120V AC. Apply 120V AC between LIN2 and N.
Verify voltage before regulator (on C104) around 20Vdc and after regulator (on C105) around 12Vdc.
Change jumper setting to 240V AC. Apply 240V AC between LIN2 and N.
Verify voltage before regulator (on C104) around 20Vdc and after regulator (on C105) around 12Vdc.
Change jumper setting back to 120V AC.
For the following tests use a "bypassed" power-supply jig powered from a variac.
Install Temporary jumper under the relay K101 and K201 (short the relay).
Connect the secondary winding of the transformer to AC101 and AC103 and the Center Tap to AC102.
Bring up the AC gradually (in 15V steps) while measuring the MOSFET supplies at +M101 and –M101 relative to
ground at AC104. 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 way on other side of board as follows.
Connect the secondary winding of the transformer to AC201 and AC203 and the Center Tap to AC202.
Bring up the AC gradually (in 15V steps) while measuring the MOSFET supplies at +M201 and –M201 relative to
ground at AC204. 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 on both sides.
Also remove the temporary jumper from relays K101 and K201 and re-solder relay pins properly.

Testing Capacitor Board (B3A1XR00)

For the following tests use a "bypassed" power-supply jig powered from a variac.
Connect the secondary of transformer to AC2 and AC4 and Center Tap at AC6.
CA(P)2100 AMP Service Manual v1.4 inc voltage change info .doc Page 9 of 50