CHANGING LIFTER BOARD

AC-500

REMOVING AC-500 FROM ITS CASE

Slide a screwdriver under the chrome handle cover and snap it off, exposing the two bolts which hold the handle in place. Remove these bolts. On the opposite side of the unit, locate the two rubber feet. Remove the bolts that hold these feet in place.

Make sure the tone arm is locked in its clip. Lift out the platter, and set it aside. Turn the set on its right side and pull the front of the chassis away from the case about 3 or 4 inches CAUTION! - PULLING THE FRONT TOO FAR TO THE RIGHT OR FORWARD BEFORE PULLING THE BACK TO THE RIGHT CAN CAUSE PERMANENT DAMAGE. Push the back forward just far enough to clear the RCA jack on the rear. Pull the back out until it JUST clears the case. There are two cables plugged into the power supply, note the location of the plugs and unplug them. The power supply will remain in the case. Slide the chassis to the right and out of the case.

               INSPECTION AND FAMILIARIZATION

Turn the chassis upside down on some padding with the controls toward you. The lifter electronics are contained on the printed circuit board located on the left side of the set. Check the cables to be sure they are in place.

There are two plugs on the lifter board: the 8 PIN control /voltage and the lifter motor. Inspect these cables and note the orientation of the plugs.

                    BOARD REPLACEMENT

Remove the control / voltage cable from the lifter board. Unscrew the 4 screws on the left side of the chassis that secure the lifter board. Remove the lifter motor cable from the old board and attach it to the new board. INSURE THAT THE BLACK WIRE IS CLOSEST TO THE LONG SIDE OF THE BOARD (PIN 1). Move the lifter power switch to its “ON” position (toward the end of the board with the three adjustment controls). Mount the board in the chassis with the switch just touching the “ON” end of the slot in the top deck. Tighten the mounting screws, and make sure the switch can move fully in both directions. Connect the control / voltage cable and check that it connects to all eight pins.

CAUTION! PERMANENT DAMAGE CAN BE CAUSED BY CARELESS RE-ASSEMBLY!

The post at the rear of the left chassis side panel (behind the lifter board) must be kept clear of the power supply capacitors.

To re-assemble, stand the case upright on its right side. Line up the chassis parallel to the bottom of the case with the back edge just far enough forward to clear the RCA jacks. Check that the post will clear the capacitor on the power supply. Slide the chassis part of the way in and when the jacks are clear slide it to the rear. To reconnect the cables, swing the front of the chassis to the right no more than 3 to 4 inches. Be careful not to allow the front of the set to come too far out of the case while the back is still in the case.

LIFTER ADJUSTMENTS AC-500

Adjustments are made with the set right side up and the platter in place. On the right side of the set there is a 1 inch opening with access to three screwdriver adjustments. The top left sets the low or rest point. The bottom center sets the high or up point. The top right is a factory set adjustment of the cycle speed, and should not need adjustment.

Set the lifter arm stop point so that the arm would drop in the lead-in groove of a record. With the power off, manually raise and lower the reset arm to find the proper setting.

Place the tone arm on its rest and turn the set and the lifter on. Adjust the low (top left) so that the lifter arm is just above the top deck. Press and hold the reset button and adjust the high adj (lower) so the needle is about 1/8 inch off the record. Release the reset button and reset the low point. The low and high adjustments interact slightly and you must work back and forth a couple of times.

REFINING THE ADJUSTMENTS

Most callers never reset to the start of the record. You may place the stop to the point you are going to use for your records and reset the high point. This will result in a lower setting off the record and a softer needle drop. However it will have to be reset if the stop is moved.

If necessary the speed may be adjusted to your desires. If the tone-arm bounces when lifted from the center of the record, the speed is TOO FAST. If the high point is correct and the needle slides across the record the speed is TOO SLOW.