Disassembly Instructions:

With the power removed from the unit, remove the electrode tip, and then remove the 10-32 hex nut by using the special 5/16 in. nut driver.

Then remove the top half (smooth cone portion) of the plastic housing by turning it counterclockwise.

Turn the black adjusting knob counterclockwise and remove it by holding the brass adjusting screw with the special 3/16-in. wrench, and turning the knob ounterclockwise. Save the plastic and fiber washers. The number of washers may vary from one unit to another.

On each side of the adjusting screw are two metal screws covered by wax. Remove and save the wax, and remove the screws.

Slide the rear plastic housing back and expose the internal parts of the unit. During this operation, for the Model BD-10AS, pull the black plastic button up to avoid interference while the housing is being removed.

Troubleshooting:

Observe the adjusting screw for worn threads. Replace if this is observed. Note that on Model BD-10A (unit without switch), some customers incorrectly use the adjusting knob as an "ON/OFF" switch. This practice prematurely weas out the threads. Customers must be warned not to do this, but do use a power strip or similar device to turn the unit on and off.

Next observe the contacts. They must be aligned to each other's center as much as possible, and must be corrosion and burn-spot free. If corrosion or burn spots are observed, clean with a fine file, or replace. Make sure the bottom contact has enough room on the bottom, so that when the top spring is pushed against it, the bottom contact does not get pushed into the molded spool core.

Use a multimeter to check the power cord for any broken wires. Replace if it is found that the customer has used tape to cover frayed insulation.

Check the magnet coil for broken wire leads. Use an ohmmeter to measure the resistance of the magnet coil. If the coil resistance is zero (open), replace it.

Check the yellow capacitor using an ohmmeter. Check for broken leads. If power is applied to the unit, and it makes a knocking sound (from the armature bottom spring making contact with the spool core), but there is no output, the capacitor is bad. Replace it if any of these conditions are present.

Use an ohmmeter to check the resonator coil. If no resistance, check for broken lead wires, or replace the resonator coil. If the unit is powered, and arcing is observed inside the resonator coil, replace it. If the unit works Okay, but has a weak output, the resonator coil is defective. Replace the resonator coil if any of these conditions are present.

The Model BD-10AS has a microswitch to turn power on and off to the resonator. Check the switch for broken wire leads. If leads are Okay, test the switch for continuity with a multimeter. Replace if bad.

If the unit is working, but the output is reduced, check the resonator coil, the capacitor, and the contacts.

Assembly Instructions:

For the Model BD-10AS, make sure the microswitch aligns with the pushbutton.

Install the plastic housing, 10-32 nut, and screws to the proper position.

To avoid a potential shock hazard, cover the screws with wax as before.

Install the adjusting knob on the adjusting screw. Turn the knob clockwise until the unit turns on. Turn the knob clockwise until it shuts off. Back up the knob until the unit turns on again. Remove power from the unit and install the plastic or fiber washers into the space between the plastic housing and the adjusting knob. Tighten the knob securely.

The unit should sound smooth when turned on. If the adjusting knob is turned too far into the unit, a loud vibration will be heard, the output will be high. If left in this position, the internal parts will begin to burn up. Back off the knob to the position which has a smooth sound.

If the contacts were replaced, the number of adjusting washers may vary with what was used before contact replacement. If the contacts were not replaced, the same number of adjusting washers can be used.

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