COMPONENT WORK SAMPLE 15 Electrical Circuitry & Print Reading MAINTENANCE MANUAL

TABLE OF CONTENTS SECTION TITLE PAGE 1A CHECKING THE BATTERIES, METER AND PROBES... 1 1B SECTION A: CHECKING THE COUNTER... 1 1C SECTION B: CHECKING THE POWER CORD, LIGHTS... 1 1D SECTION C: CIRCUIT CHECK... 1 2 TROUBLE SHOOTING TABLE... 2 3A REWIRING THE PROBE... 3 3B REPLACING THE METER... 3 3C REWIRING THE POWER CORD PLUG... 3 3D REPLACING THE SPRING CLIP TERMINALS... 3 3E REPLACING LEDs (LIGHTS)... 4 3F REPLACING THE COUNTER... 4 DIAGRAMS 15.1 VCWS15 WIRING DIAGRAM... 5 i

1A CHECKING THE BATTERIES, METER AND PROBES The most commonly encountered problem with the VCWS15 is weak batteries. The batteries can be tested by using the meter. The uppermost battery pack contains the top four batteries and is connected to the meter and both probes. To determine that the meter is functioning properly, insert four new batteries into the top pack. Touch the two probes together. The meter should read greater than +5 volts. If your meter reads less than +5 volts, refer to section 2A of this guide. If the meter functions properly, all the batteries for the work sample can be checked. Remember, the upper battery pack must be used when testing the batteries. If the meter reads less than +5 volts, the batteries need to be replaced. 1B SECTION A: CHECKING THE COUNTER Check the counter by touching the black probe to the rivet in Section A, Part 7, in the lower right corner. When the rivet is tapped lightly, the counter should begin counting. If the counter does not count, refer to part 2B of this troubleshooting guide. 1C SECTION B: CHECKING THE POWER CORD AND LIGHTS Plug the power cord into Section B, Practice A. When the button is pressed, the red light should come on. If the light fails to come on, plug the power cord into Practice B and place a jumper wire between the spring clip terminals. If the light fails to go on when the button is pressed, refer to part 2C of this troubleshooting guide. When either light goes on, the power cord circuit is working properly. 1D SECTION C: CIRCUIT CHECK Wire Section C following the diagram for Part 1 of this section. Plug the power cord in and press the button. The two green lights should come on. When the lights come on, jump the lower right spring clip terminal to the one above it. When the button is pressed, the red light should also come on. If any of the lights do not function, refer to part 2C of this troubleshooting guide. 1

SECTION 2 VCWS15 TROUBLE SHOOTING TABLE 1/25/00 PROBLEM POSSIBLE CAUSE SOLUTION 2A METER DOES NOT WORK 1) WEAK BATTERIES REPLACE BATTERIES 2) DEFECTIVE PROBES REWIRE PROBES REFER TO PART 3A 3) BROKEN PROBE WIRES REPLACE PROBE WIRES 4) DEFECTIVE METER REPLACE METER REFER TO PART 3B 2B COUNTER DOES NOT WORK 1) WEAK BATTERIES REPLACE BATTERIES 2) DEFECTIVE BLACK PROBE REWIRE PROBE REFER TO PART 3A 3) BROKEN PROBE WIRE REPLACE PROBE WIRE 4) WIRE TO CIRCUIT BOARD IS DISCONNECTED CONNECT THE WIRE BETWEEN THE CIRCUIT BOARD AND COUNTER 5) DEFECTIVE COUNTER REPLACE THE COUNTER REFER TO PART 3F 2C SOME OR ALL OF THE LED'S DO NOT LIGHT 1) WEAK BATTERIES REPLACE BATTERIES 2) POWER CORD REWIRE POWER CORD REFER TO PART 3C 3) DEFECTIVE SWITCH REPLACE SWITCH 4) DEFECTIVE SPRING CLIP TERMINALS REPLACE SPRING CLIPS REFER TO PART 3D 5) DEFECTIVE LED'S REPLACE LED'S REFER TO PART 3E 2

3A REWIRING THE PROBE Unscrew the nut (located behind the metal point and in front of the plastic probe handle) from the probe. Twisted under the nut is the exposed wire that comes through the probe. Untwist the wire and pull it out of the plastic end of the probe. Cut approximately one inch off the end of the wire. Expose one-half inch by stripping. Twist the exposed wire together tightly. Insert the wire into the probe making sure the exposed section goes through the hole near the top of the probe. Wrap the exposed wire tightly clockwise around the base of the metal part of the probe. Replace the nut and tighten. 3B REPLACING THE METER Remove the plastic cover from the meter by pulling it straight up. Remove the four screws that mount the meter to the insert. Use a small screwdriver to gently pry the meter out of the box. Disconnect both wires from the old meter. Reconnect the wires to the new meter. Be certain the wires are reconnected to the same side of the meter. Mount the new meter by reversing the above steps. 3C REWIRING THE POWER CORD PLUG Unscrew the plastic cover from the power cord plug. The plug has two wires connected to it. The black wire is connected to the short terminal and the white wire is connected to the longer terminal. Remove the wires from the plug by melting the solder with a soldering iron. Cut approximately one inch off the end of both wires. Expose one-eighth inch by stripping. Resolder both the wires to the plug. Replace the plug cover and retest the power cord. 3D REPLACING THE SPRING CLIP TERMINALS Occasionally, due to constant use, the spring clip terminals need to be replaced. Because of a change in the style of the terminals if one needs to be replaced they all need to be replaced. If a soldering iron is available, this can be done in the field. Begin by removing the six screws that hold the circuit board to the box. Gently turn the circuit board over being careful not to disconnect the wires. Using the soldering iron, heat the solder holding the terminal to the circuit board. When the solder turns to liquid, use the tip of the soldering iron to push the terminal out. Be very careful not to ruin the trace on the circuit board. Reheat the solder and insert a new terminal from the front. Let the solder cool, then check if the terminal is firmly mounted to the circuit board. More solder may have to be added to secure the spring clip to the circuit board. Check if the terminal is straight in the circuit board. If necessary reheat the solder and straighten the terminal. Repeat this procedure until all the defective spring clip terminals are replaced. Using the same six screws, remount the circuit board. 3E REPLACING LEDs (LIGHTS) 3

Remove the six screws that mount the circuit board to the box. Using a soldering iron, melt the solder that connects the leads from the defective LED to the circuit board. Pull the LED out of its light cover. Note the orientation of the flat side of the LED to the circuit board. Replace the LED with a new one, being certain that it is mounted in the same direction as the old one. Solder the leads from the LED to the circuit board. Repeat these steps for all the defective LEDs. Remount the circuit board using the same six screws. 3F REPLACING THE METER Remove the two screws that mount the counter to the circuit board. Use a small screwdriver to gently pry the counter out of the insert. Lift the counter up until its soldering terminals are exposed. Use a soldering iron to unsolder the two wires from the counter. Solder the two wires to the new counter. Mount the new counter with the same two screws. 4