Elenco 3 1/2 Digit Cap. / Trans. Kit - Manual (Page 26)

-10-
PARTS LIST - SECTION A
If you are a student, and any parts are missing or damaged, please see instructor or bookstore.
If you purchased this kit from a distributor, catalog, etc., please contact ELENCO
® (address/phone/e-mail is at
the back of this manual) for additional assistance, if needed. DO NOT contact your place of purchase as they
will not be able to help you.
RESISTORS
Qty. Symbol Description Color Code Part #
r 2 R4, R5 100k
Ω
5% 1/4W brown-black-yellow-gold 161000
r
1 R3 200k
Ω
5% 1/4W red-black-yellow-gold 162000
r 1 R1 220k
Ω
5% 1/4W red-red-yellow-gold 162200
r 3 R7, R8, R9 470k
Ω
5% 1/4W yellow-violet-yellow-gold 164700
r
2 R2, R6 1M
Ω
5% 1/4W brown-black-green-gold 171000
CAPACITORS
Qty. Symbol Value Description Part #
r
1 C5 100pF (101) Disc 221017
r 1 C1 .1
μ
F (104) Mylar (large brown) 251017L
r
3 C2, C3, C4 .1
μ
F (104) Mylar (small yellow) 251017S
r 1 C6 22
μ
F Electrolytic (Lytic) 272244S
SEMICONDUCTORS
Qty. Symbol Value Description Part #
r 1 T1 9013 Transistor 2SC9013 329013
MISCELLANEOUS
SECTION A
Meter Display Circuit
Resistor
PARTS IDENTIFICATION
Diode PC Board Liquid Crystal Display (LCD)
Qty. Description Part #
r
1 LCD 351166
r 1 Zebra 500007
r
1 PC Board M2666K 512666
r 1 Switch On/Off (SW1) 540004
r
1 Battery 9V 590009
Qty. Description Part #
r
1 Battery Snap (Batt) 590098
r 1 LCD Housing 629015
r
1 LCD Cover 629016
r 1 Label Top 723051
r
2 Solder 9LF99
Transistor
Label Top
Display
Housing
Display
Cover
Zebra
LCD
Capacitors
Disc Lytic Mylar
C1
-25-
U1 (7106) Voltage Test
1. Measure the voltage across pin 8 and pin 34 on
U1 (7106) for 9V.
A. Check the battery and SW1 connections.
B. Check for a 9V and GND short.
1. One of the ICs may be bad. Remove
one IC at a time and check voltage
again between pins 8 and 34.
2. Measure the voltage from pin 8 to COM on U1 for
3V.
A. U1 is defective.
3. Check the Main Oscillator on U1 (7106) pins 6, 7,
and 4.
Pin 6
Pin 7
Pin 4
4. Measure the voltage from pin 44 to COM on U1
(7106) = 0.1V.
A. Adjust VR1 so the the junction of R31,
R33 and VR1 equal to 100mV.
1. Can’t set to 100mV.
a. VR1 wrong value or defective.
b. R30 - R32 wrong value.
Voltage/OHM Section
1. Measure across V
Ω
CAP terminal and COM
terminal for 10M
Ω
(set meter in 200mV) battery
installed.
A. Lower or higher than 10M
Ω
.
1. Check resistors R10 - R18.
2. LCD readings floating.
A. Measure from COM terminal to pin 43 on
U1 (7106) for 220k
Ω
.
1. R3 open or defective.
AC Voltage Section
1. Apply 15VAC to meter and measure pin 14 of U2
(324) to COM terminal with a scope (meter on
20VAC scale).
Pin 14 to COM 2Vpp
A. Check IC2 and R34
2. Check junction R39 and C11 of U1 (7106) with a
scope.
Waveform for junction R39 and C11.
A. Check R35 - R39, C7 - C11, D3 - D5, and
VR2.
.16Vpp
If the meter is not working, perform the U1 (7106)
Voltage Test first. This test is to verify that the IC and
Reference Voltage are operational. Then perform the tests that pertain to the Function that is not
working on your meter.
TROUBLESHOOTING GUIDE
.03Vpp
0V