This document provides an overview of various tools and techniques used in electronics repair, including: - Multi-meters, oscilloscopes, logic probes, and function generators for testing circuits. - Microscopes and borescopes for inspection. - Desoldering and soldering equipment for component-level repairs. - In-circuit testers and logic analyzers for debugging logic problems. - Advanced techniques like pinpoint technology and auto-point DT for reverse engineering and fault isolation without schematics. - Considerations for cleaning and maintenance of circuit boards.

2. Presented by
Faisal Ghazanfar
Senior Scientific Officer
Repair & Instrumentation
section, APCIC
PCSIR Labs. Complex Karachi
Pakistan

3.  Oscilloscope, Multi-meter, Logic Probe, Function
generator, SMD Rework station, Soldering and de-
soldering of SMDs
 Bore-scope: To View in side equipments
 In-circuit Tester & Out-circuit Tester
 Chemicals In Repair
 Introduction to Logic analyzer
 Inspection Microscope
 State of art technologies
◦ Pinpoint technology ( reverse engineering)
◦ Fault finder (component level testing)
◦ Auto-point DT (prob/camera current and voltage ratio chart)

4. Digital
Multimeter
Logic Probe
Oscilloscope
Soldering
tweezer
Function Generator

5. 1. Multi-meter (Digital/Analog)
◦ Current (AC/DC)
◦ Ampere (AC/DC)
◦ Capacitance (to some range)
◦ Resistance etc.
 Precautions/common mistakes
◦ For current measurement, must change probe
position, otherwise meter fuse blown/damage
◦ Do not use meter above meter current rating
◦ In case of miss use/mistake check fuses in side
meter
◦ Drops during working may damage the meter

6. 2. Oscilloscope (criteria to select max. frequency,
Digital storage oscilloscope )
◦ View AC/DC signals
◦ Pluses of different shapes
◦ e.g encoder, flow sensor, etc
 Precaution/common mistakes
◦ Calibrate the scope before use(connect probe with
calibration point of scope)
◦ Selection of mode of oscilloscope single channel,
dual channel and multichannel

8. STM32F103 microcontroller, two 12bit ADC

9. 3. Capacitor tester/meter
◦ Polar and non polar testing of capacitor
◦ Selection of range
◦ Connections of capacitor to meter leads
4. Logic probe
◦ To see/view signals/pulses of TTL/CMOS
◦ CMOS LOW:0V to 1/3VDD ;HIGH: 2/3 VDD to VDD
◦ TTL LOW:0V to 0.8V ;HIGH:2V to VCC
◦ Commonly used to see clocks, missing clocks in
pulse encoder
◦ For full stream used oscilloscope, logic analyzer

11. 5. Function generator/Pattern Generator
◦ Generation of waves/signals of different forms e.g.
saw tooth, sin waves, square etc
◦ Applied to by pass turbine Flow sensor/chopper in
machines
◦ Used as a Clock for many circuits such as crystals
replacements
◦ Encoder of motors produced pattern of signals
which provide speed information.

12.  It used for nondestructive inspection of hard-
to-reach places such as motors, pistons,
gears, valves, compressors, boilers and
condenser tubes.
 It helps you locate potential problems quickly
and easily without the need to dismantle a
system or machine.
 Forward and backward view
 Reading make model date etc at back side

13.  video

14.  Dual in line
package(DIP)
 Ball grid array (BJA)
 Plastic leaded chip
carrier package(PLCC)
 Quad flat package(QFP)
 Quad flat no-
leads(QFN)
 Small outline IC (SOIC)
 To remove such kind
of IC’s and test is
highly risky so other
methods are adopted
such as online tester

15.  IC’s testers (ZIP socket problem,
software/windows, )
◦ IC function test actually check truth table of IC
◦ Loop test, function test are performed.
◦ microcontroller, programmable peripheral
interface(PPL), memories
◦ Analog IC’ tester
 Operational amplifiers
 Instrumentation amplifier
 Problems
◦ Remove IC to test, Reverse connections
◦ Different package different sockets

19.  To remove IC’s and test
them is highly risky
 Resolding may be wrong/
difficult few legs of IC’s
may be required
resolding
 so other methods are
adopted such as online
tester
 Some IC required clock,
pattern signal,
Independent Power
supply…..to test
(microprocessors,
multiplexer)

20.  To test an In side circuit we required
following
◦ Power supply of test IC’’s card
◦ Input Pattern of test IC
◦ View results/output of IC
 The requirements of In-circuit IC tester.
◦ Having software
◦ Equipment contains oscilloscope,
◦ Pattern generator
◦ Multimeter, power supply
◦ Programmable clock

21.  Digital functional test (in- and
out-of-circuit)
 Analogue functional test (ICs
and discrete devices)
 Graphical test generator
 Live comparison of two IC’s
 Digital and analogue V-I test
 Digital IC identifier
 EPROM verifier
 Short locator
 Digital oscilloscope, digital
multimeter, function
generator, frequency/event
counter, universal I/O
 Automated fault-finding
sequences
 Variable power supply

22. De-soldering
tweezers

23. Soldering tips
De-Soldering
nozzles

24. IC
Regulator

25. Leg break Soldering IC
Wire & hemostat
Look Direction of Track
Soldering wire
Connection established

26. •Legs must be in line
•Solved by using wick to clean
additional solder (video)

27.  Water+ detergent  used to clean
sticky/humid dust
 IP (Isopropanol)/sprite  used to
primary clean of cards
 CTC (carbon tetra chloride) is a contact
cleaner, used for moving parts
 WD-40  this solution is used to remove
rust, it is conducting so need to remove fully
before turn on card
 Kerosene oil  in case of battery drain on
card+ rust+ dust etc you need to used it.

28.  Methanol (HPLC grade~99.99% pure) used to
clean/ washed those parts of instrument involved
with ionization/detection/sensing /flow of
sample (specially for MS,AA)
 Using for cleaning of optics such as lenses, prism
Gratting in spectrophotometers
 Using for cleaning of vacuum sensors such as
dynode/quadropole in MS.
 Cleaning of Ionization parts of MS
 Air/Nitrogen/inert gas to dry sensitive parts of
equipments
 Acetone can also be used

31. 1. Remove cards by tagging of wires and
connectors. (make video/pics)
2. Remove dust from card (water + detergent)
3. Remove mechanical components such as heat
sinks, fan, connectors etc
4. Clean using chemicals such as CTC,WD-40,
kerosene oil (dip for heavy corrosion)
5. Carefully use brush on SMD component
6. Drying the card using air jet, hot air nitrogen etc.
7. Physical check or microscopic checking of cards.
(missing tracks, through holes, cracks on IC’s)

33.  It is used for
physical check of
PCB’s
 Joints of IC’s
 Dry soldering also
viewed
 Problem: through
hole, multi layer
cards

35. Some logical problems are:
 Clock generation problem to
processor/controller of instrument under
repair
 Data/ Address bus problem faulty
 Garbage on screen
 Some addresses of memory are un identified
 Processor hang
 Firmware problem/BIOS problem
 Debugging of such above problems we use
special equipment called Logic Analyzer

37.  A logic analyzer is useful Tool in Debugging Digital
Electronic Circuits during development stage, especially
where, fast logic circuits are involved with lots of signals,
whose relations have to be Verified or Examined.
 During the process of Debugging and Validating a digital
system, the common task is the ‘Acquisition of Digital
Waveforms’.
 A logic analyzer is a tool that allows numerous digital
waveforms to be Acquired simultaneously.
37

38. A logic Analyzer is like a recorder for digital
signals:
1. During a certain period of time, the state of
a few digital lines may be recorded to a file.
2. An event can be specified to signal the start
of the recording i.e line 1 toggling from high
to low
3. This recording can be viewed afterword,
allowing for zooming and scrolling in the
time domain.

39.  This is a test and measuring tool, which
provides “solution to a particular class of
problems”.(firmware)
 It is a versatile tool for
◦ Digital hardware design
◦ Design verification
◦ Embedded software debugging (programmed IC’s)
 It is used for digital measurements involving
numerous signals on challenging trigger
environment.

40.  Recorded many channels simultaneously (68)
 Sampling rate upto one million sample per
second or more depending on system.
 Recorded thousand of samples (32000)
 Save and load recording to / from disk
 Use a “Advanced trigger control” scheme. i.e.
it wait for a channel to remain stable for a
given time (delay) and them it starts sampling
after the first change of that channel.

44.  In multilayer, SMD component PCB it is impossible
to find faults using conventional methods and
tools.
 Without schematic diagrams the repair and
troubleshooting is a challenge.
 Some modern technologies like pin-point and
auto-pint DT are used to solve such problems.
 Pinpoint draw the schematic and make it easy to
find the faults.
 Without power the full PCB it can find the faults.

46.  Using for highly sophisticated diagnosis such
as radars, control circuits of ships/sub
marines etc.
 Many ranges are available with different
features such as pinpoint alpha, pinpoint
ranges, pin point II R etc.
 Dedicated software are their to run such
sophisticated fault finding solution
equipments

47.  How reverse engineering perform
 IC logical testing without remove from card
 Connection from pin point to card
 Schematic drawing
 Firmware testing

49.  Automatic diagnostics and probing
 Power-off test techniques for safe testing
 No knowledge of board required so can
be used on all circuits
 Error-free probing for accurate and fast
diagnostics
 Standalone or Integrated implementation
for scaleable levels of test

51.  Current and voltage are fundamental property
of all components in electronics
 Ground the PCB under test
 The probe attached with camera, touch the
selected component under test, and give
some voltage (+ve).
 The system diagnose the current pass
through the circuit and plot the voltage vs
current plot.
 If there is a problem it will diagnosis
completely.

53.  www.diagnosys.com/products/pinpoint-ii-r
 www.home.agilent.com
 Embedded system design Lab.
PCSIR Labs. Complex, Karachi
 CDLE, PCSIR Labs. Complex, Karachi
 www.tribalmicro.com/all-100/
 Sys-tech corporation
 https://www.sparkfun.com/tutorials