Elenco Electronics 202 - Manual (Page 8)

-7-
Advanced Troubleshooting
(Adult supervision recommended)
Radio Shack is not responsible for parts damaged due to incorrect
wiring.
If you suspect you have damaged parts, you can follow
this procedure to systematically determine which ones
need replacing:
1. 6V lamp (L2), motor (M1), speaker (SP), and battery holder
(B1):
Place batteries in holder and install bulb in lamp socket.
Place the 6V lamp directly across the battery holder, it should
light. Do the same with the motor (motor + to battery +), it should
spin to the right at high speed. “Tap” the speaker across the
battery holder contacts, you should hear static as it touches. If
none work, then replace your batteries and repeat. If still bad,
then the battery holder is damaged.
2. Snap wires: Use this mini-
circuit to test the 5-snap
and 6-snap wires. The lamp
should light. Then test each
of the 1-snap, 2-snap, 3-
snap, 4-snap, and 7-snap
wires by connecting them
between the ends of the 5-
snap and 6-snap.
3. Slide switch (S1) and Press switch (S2): Build project #1, if
the lamp (L2) doesn’t light then the slide switch is bad. Replace
the slide switch with the press switch to test it.
4. LED’s (D1 & D2) and 100 Ω (R1), 1KΩ (R2), 5.1KΩ (R3), and
10K Ω (R4) resistors: Build project #7 except initially use the
speaker (SP) in place of the LED, you will hear static if the resistor
is good. Then replace the speaker with the LED and see if it lights.
Then, replace the 100 Ω resistor with each of the other resistors,
the LED should light, but the brightness decreases with the higher
value resistors. Test the green LED in the same manner.
5. Alarm IC (U2): Build project #17, you should hear a siren. Then
place a 3-snap wire between grid locations A1 & C1, the sound
is different. Then move the 3-snap from A1-C1 to A3-C3 to hear
a third sound.
6. Music IC (U1): Build project #74 but use the press switch (S2)
in place of the photoresistor (RP). Turn it on and the LED (D1)
flickers for a while and stops. It resumes if you press and hold
down the press switch. Then, touch a 3-snap wire across base
grid points A1 & C1 and the flickering resumes for a while.
7. Space war IC (U3) and photoresistor (RP): Build project #19,
both switches (S1 & S2) should change the sound. Then replace
either switch with the photoresistor, waving your hand over it
should change the sound.
8. NPN transistor (Q2): Build the mini-circuit shown here. The LED
(D2) should be on only when the press switch (S2) is pressed.
9. PNP transistor (Q1): Build the mini-circuit shown here. The LED
(D2) should be on only when the press switch (S2) is pressed.
10. Antenna (A1): Build project #246, the LED (D1) should flash
when you release the press switch (S2).