BENDIX IN-20258 User manual

ÂILLIED Bendix
~ Aerospace
1. General
Bendix General Aviation
Avionics Division
MAINTENANCE MANUAL
IN-20258 MULTIFUNCTION COLOR INDICATOR
SECTION V MAINTENANCE PRACTICES
This section contains inspection procedures, cleaning information, repair
information, and semiconductor and integrated circuit service information
for the
IN-20258 Multifunction Color Indicator.
2. Inspection
Perform a routine visual inspection any time the radar indicator is removed
from the aircraft. Pay special attention to the following areas.
A. Oust Caver
Inspect the dust caver for dents, deformation or damage to the finish
that should be repaired.
B. Chassis
Inspect chassis for loose or missing hardware, deformation,
damaged
fasteners, or damaged connectors. Also check for corrosion or damage
to the finish that should be repaired.
C. Connectors
Inspect connecter
body for broken parts; check insulation for cracks.
Check pins for damage, corrosion, misalignment, or bad plating. Check
for broken, loose, or poorly soldered connections to terminals of
connectors. Inspect cable
clamps for pinched wires.
o. Terminal Connections
Inspect for corrosion
and loose connections.
E. Wi ring
Inspect chassis wiring
and subassemblies for any physical damage or
charring.
F. Capacitors
Inspect for case or
body damage and for loose, broken, or corroded
terminal connections.
G. Resistors and Diodes
Inspect for blistered, charred, or cracked bodies. Check for loose,
broken, or corroded terminal connections.
I.B.
21400C
PART 4 5-1
Mar/86
The document reference is online, please check the correspondence between the online documentation and the printed version.

2.
H.
~ General Aviation
~ Avionics Division
MAINTENANCE MANUAL
IN-20258 MULTIFUNCTION COLOR INDICATOR
Filters and Inductors
Inspect for
damage to body or casing and for loose, broken, or corroded
terminal connections.
Check for secure mounting to chassis.
1. Transformers
Inspect case for
damage and for signs of excessive heating. Check for
loose, broken, or corroded terminal connections.
J. Transistors and Integrated Circuits
Inspect for damage to body or case and for secure attachment to socket.
K. Terminal Connections, Soldered
(1) Inspect for cold soldered or rasin joints. Bad joints can be·
recognized by a dull, porous appearance.
(2) Check for excessive solder, insufficient solder, or solder
splashes resulting
from a previous repair.
(3) Check for corrosion at the terminal connections.
L. Rotary Switches
Check for proper mechanical operation; no binding or looseness should
be evident.
M. Printed Circuit Boards
Inspect for loose, broken or corroded terminal connections and damage
such as cracks, burns or charred track. Also, check for insufficient
solder, proper binding, fungus, mold or other deposits that should be
repaired.
N. Cathode-Ray Tube
Inspect tube face for burned spots or ether discrepancies which could
cause deterioration of the display.
Check tube for secure mounting.
O. CRT Fi lter
Check CRT filter for scratches or other blemishes which could cause
deterioration of the display.
1.B. 21400C
PART 4
5-2
Jun/84
The document reference is online, please check the correspondence between the online documentation and the printed version.

~ General Aviation
~ Avionics Division
MAINTENANCE MANUAL
IN-2025B MULTIFUNCTION COLOR INDICATOR
3. Cleaning
Perform a routine cleaning any time the radar indicator is removed from the
aircraft.
A. Recommended Cleaning Agents
Table 5-l lists the recommended cleaning agents to be used during
overhaul of the
IN-2025B.
TYPE
USED TO CLEAN
Denatured Alcohol
Exterior surfaces (except CRT filter)
and interior surfaces.
Isopropyl
Alcohol
Printed circuit boards.
Glass Cleaner
(Windex or
CRT filter.
or equivalent)
Recommended Cleaning Agents
Table 5-l
B. Recommended Cleaning Procedures
WARNING: GOGGLES ARE TO BE WORN WHEN USING PRESSURIZED AIR TO BLOW
OUST AND DIRT FROM EQUIPMENT. ALL PERSONNEL SHOULD BE
CLEARED FROM THE IMMEDIATE AREA.
WARNING: OPERATIONS INVOLVING THE USE OF A CLEANING SOLVENT SHOULD BE
PERFORMED UNDER A VENTILATED HOOD. AVOlD BREATHING SOLVENT
VAPOR AND FUMES; AVOlD CONTINUOUS CONTACT WITH THE SOLVENT.
CAUTION: USE ONLY RECOMMENDED CLEANING SOLVENTS ON ELECTRICAL PARTS.
MANY AVAILABLE CLEANING SOLVENTS CAN SOFTEN AND PERMANENTLY
DAMAGE INSULATING MATERIALS.
CAUTION: ALUMINUM ELECTROLYTIC CAPACITORS CAN BE DAMAGED BY
HALOGENATED HYDROCARBON SOLVENTS. BENDIX AVIONICS RECOMMENDS
11
lSOPROPYL ALCOHOL" AS A SAFE CLEANING SOLVENT FOR PRINTED
CIRCUIT BOARDS CONTAINING ALUMINUM ELECTROLYTIC CAPACITORS.
OTHER SOLVENTS WHICH MAY BE USED ARE AS FOLLOWS:
I.B. 21400C 5-3
PART 4 Jun/84
The document reference is online, please check the correspondence between the online documentation and the printed version.

3.B.
~ General Aviation
~ Avionics Division
MAINTENANCE MANUAL
IN-2025B MULTIFUNCTION COLOR INDICATOR
SAFE SOLVENTS
XYLENE
ETHYL ALCOHOL
BUTYL ALCOHOL
METHYL ALCOHOL
PROPYL ALCOHOL
CALGONITE (A BRAND OF DETERGENT)
PRINTED CIRCUIT BOARDS CONTAINING ALUMINUM ELECTROLYTIC
CAPACITORS SHALL NOT BE CLEANED WITH THE FOLLOWING SOLVENTS:
UNSAFE SOLVENTS
FREON TF, TMC
CARBON TETRACHLORIDE
CHLOROFORM
TRICHLOROETHYLENE
TRICHLOROETHANE
ALL (A BRAND OF DETERGENT)
METHYLENE CHLORIDE
(1) Perform exterior cleaning as follows:
(a) Wipe dust caver and exterior of chassis with a lint-free
elath dampened with denatured alcohol.
(b)
Use a clean camel's hair (or equivalent) brush saturated with
denatured alcohol
ta remove any foreign matter from rear
connecter.
(c)
Clean CRT filter with a lint-free elath slightly dampened
with Windex glass cleaner.
(d) Open any blocked ventilation hales in the dust caver by first
saturating the debris clogging the apertures with denatured
alcohol
and then blowing the loosened material out with an
air stream.
(2) Perform interior chassis cleaning as follows:
I .B. 21400C
PART 4
CAUTION: AVOlD AIR-BLASTING DELICATE PARTS.
(a) Remove dust and other dirt from all surfaces, including parts
and wiring, using a soft bristle, camel's hair (or
equivalent) brush
in conjunction with a clean, dry air jet
(25 to 38 psi).
5-4
Jun/84
The document reference is online, please check the correspondence between the online documentation and the printed version.

1
BENDIX/KING
MAINTENANCE MANUAL
IN-20258 MULTIFUNCTION COLOR INDICATOR
(b) Any dirt that cannat be removed in previous step should be
removed using a soft bristle, camel's hair brush saturated
with isopropyl alcohol.
Use a clean, dry air jet (25 ta
38 psi) ta remove excess isopropyl alcohol and loosened
dirt.
(3) Perform printed circuit board cleaning as follows:
CAUTION: AVOlD AIR-8LASTING DELICATE PARTS.
{a) Remove dust and other dirt from board surfaces and
components using a soft bristle, camel's hair {or
equivalent) brush in conjunction with a clean, dry air jet
{25 ta 38 psi).
{b) Any dirt that cannet be removed in previous step should be
removed using a soft bristle, camel hair (or equivalent)
brush saturated with isopropyl alcohol. Use a clean, dry
air jet (25 to 38 psi) to remove excess isopropyl alcohol
and loosened dirt.
{4) Perform connecter cleaning as follows:
4. Repair
(a) Wipe dust and dirt from bodies, shells and cable clamps
using lint-free cloth moistened with denatured alcohol.
(b) Wipe dry with a clean, dry, lint-free elath.
(c) Remove dirt and lubricant from inserts, insulation and
terminals using soft bristle, camel's hair {or equivalent)
brush saturated with denatured alcohol.
(d) Ory insert with clean, dry air jet (25 ta 38 psi).
WARNING: VOLTAGE DANGEROUS TO LIFE EXISTS. REMOVE ALL POWER TO
INDICATOR 8EFORE PROCEED WITH REPAIR.
A. Repair Precautions
(1) Refer ta paragraph 4.8. for special ESDS handling precautions.
(2) Perform repairs and replace components with power disconnected
from the equipment.
(3) Use a conductive table top for repairs and connect the table ta
the ground conductor of the 60-Hz power line.
{4) Replace connectors, coaxial cable, shielded conductors, and
twisted pairs ONLY with identical items.
1.8. 21400C
PART 4
5-5
Dec/92
The document reference is online, please check the correspondence between the online documentation and the printed version.

BENDIX/KING
MAINTENANCE MANUAL
IN-2025B MULTIFUNCTION COLOR INDICATOR
(5) Reference ta "component side" of a printed circuit board in
this manual means the side on which the components are located;
"track side" refers
ta the other side.
(6) When repairing circuits, carefully observe lead dress and
component orientation. Keep leads as short as possible and
observe correct repair techniques.
(7) Observe cable routing throughout instrument assembly, prior to
disassembly,
ta enable a proper reinstallation of the cabling
during reassembly procedures.
B. Electrostatic Discharge Sensitive (ESDS) Deviees
Deviees
sensitive to electrostatic discharge are used in this
equipment. These deviees, including Metal Oxide Semiconductors
(MOS), sorne metal film resistors, and ether deviees, are susceptible
to
damage by electrostatic charges or high-voltage fields. Because
of the very high resistances in ESDS deviees, they can be damaged by
electrical sources that cannat deliver enough current ta damage
conventional semiconductors. Therefore, special precautions must be
taken during handling and rep~ir procedures to prevent damaging the
deviee.
The most common low-energy source causing damage to ESDS
deviees is the human body, which generates and retains static
electricity, in conjunction with nonconductive garments and floor
covering.
An individual can easily develop several thousand volts
of
electrostatic charge while simply walking across the floor or
moving around in a chair. Electrostatic charges of 20 kV have been
measured on personnel, and 35 kV has been measured on their
garments.
The capacitive elements in all MOS deviees can be destroyed by a
voltage
field, even when assembled into the circuit. Similar
capacitive elements in
linear integrated circuits, hybrids, and in
bipolar integrated
circuits are also susceptible ta field voltages.
Not all electrostatic damage will result in immediate catastrophic
failure. Damaged deviees may remain operating within the minimum
limits but could experience early field failure or erratic
performance.
The following precautions are recommended for ESDS circuits and are
especially important
in low humidity or dry conditions when
electrostatic problems are more prevalent.
CAUTION: ESDS DEVICES INCLUDE, BUT ARE NOT LIMITED TO, C-MOS,
J-MOS, PMOS, NMOS, SOCMOS, HMOS, MOS/FET, MICROWAVE MIXER
DIODES, SOME BIPOLAR DEVICES, AND SOME METAL FILM
RESISTORS.
I.B. 21400C 5-6
PART 4 Dec/92
The document reference is online, please check the correspondence between the online documentation and the printed version.

BENDIX/KING
MAINTENANCE MANUAL
IN-20258 MULTIFUNCTION COLOR INDICATOR
(1) Storage
Store and transport all ESDS deviees in conductive material.
Do not insert ESDS deviees into conventional plastic "snow" or
plastic trays used for storing and transporting standard
semiconductor deviees. Special
bags or containers must have a
maximum resistivity of 10 ohms/cm, or the leads of the deviee
must be shorted together through a conductive material (special
foam) having a maximum resistivity of 10
4
ohms/cm.
Modules, circuit boards, or assemblies containing ESDS deviees
must be stored in static shielding bags with a maximum
resistivity of 10
4
ohms/cm on the outer layer of the bag, and
10
12
ohms/cm resistivity in the inner layer.
A caution label shall
be attached to the outside of all
containers containing ESDS deviees. The ESDS labels are
identified
in the advisory information located in the front of
this manual. Do not remove deviee from container until
actually used or tested.
(2) Work Station
1.8. 21400C
PART 4
All equipment, tools, materials, and personnel at the work
station must be maintained at the same electrical potential.
All grounding connections shall have common point, and that
point shall
be connected to electrical ground.
Soldering irons shall
be isolated from the power line by
transformer, or shall be direct current isolated. The
soldering iron must be grounded and have a resistance of less
than 0.2
ohm from the tip to ground when the iron is hot.
Test
equipment shall have all exposed metallic surfaces
electrically connected to the test equipment power system
ground (through 200 ohms or less).
Do not use rubber mats, carpets, and rugs in the work station
area.
Use grounded conductive mats.
Do not allow nonconductive items on the workbench. This
includes such items as plastic ash trays, cellophane wrappers,
plastic tools, styrofoam coffee cups, etc.
Maintain the relative
humidity higher than 40 percent (minimum)
in the work area.
Keep all material and work surfaces CLEAN in the work area.
Wash with damp cloth when necessary.
5-7
Dec/92
The document reference is online, please check the correspondence between the online documentation and the printed version.

BENDIX/KING
MAINTENANCE MANUAL
IN-20258 MULTIFUNCTION COLOR INDICATOR
Keep the work station static-safe. Periodically check the area
with a static meter. When a dangerous reading is observed,
remove the nonconductor or take precautions to prevent contact
with ESDS deviees.
(3) Personne 1
When handling electrostatic discharge sensitive deviees or
assemblies, wear a skin-contact wrist strap connected to the
work station common ground.
WARNING: DO NOT CONNECT PERSONNEL DIRECTLY TO EARTH OR
BUILDING GROUND. COMMERCIAL GROUNDING STRAPS
CONTAIN AN INTERNAL RESISTANCE OF ABOUT ONE MEGOHM
IN THE CORD TO BLEED THE ELECTROSTATIC CHARGE FROM
THE BODY WHILE PROTECTING PERSONNEL FROM ELECTRICAL
SHOCK.
DO NOT WEAR GROUND STRAP WHEN TROUBLESHOOTING OR
TESTING HIGH VOLTAGE CIRCUITS WITH POWER APPLIED.
Do not wear smocks, gloves, finger cots, or sleeve protectors
made of plastic, nylon, or rubber in the area where ESDS
deviees are handled.
When the operator is properly grounded, contact with the
operator's
hand will provide sufficient ground for hand tools
or ether tools that may be electrically isolated from ground.
(4) Special Troubleshooting Precautions
In addition to the above considerations, the following specifie
precautions should be observed when troubleshooting or
repairing
modules containing ESDS deviees.
Do not use high velocity dry air for applying heat during
troubleshooting. Special infrared heat deviees should
be used.
Do not use Freon spray during troubleshooting. To cool
components, use antistatic quick-chill sprays.
Remember, even when the ESDS deviee is installed on a printed
circuit board it can STILL be damaged by electrostatic
discharge.
C. General Repair and Replacement Procedures
The repair or replacement of worn, damaged or defective parts
involves standard repair techniques.
1
1.8. 21400C
PART 4 5-8
Dec/92
The document reference is online, please check the correspondence between the online documentation and the printed version.

BENDIX/KING
MAINTENANCE MANUAL
IN-20258 MULTIFUNCTION COLOR INDICATOR
Make a wiring diagram or sketch before removal of any part requ1r1ng
unsoldering
of several lead wires. Show color coding or wire
marking and the approximate location and identify of the terminals
to which the wires are connected. Also, show where lacing is
removed or where dress is important.
Whenever maintenance is performed on the chassis cabling, make
continuity checks throughout the cable to check that the cable is
still wired correctly. Refer to the main frame schematic diagram
shown in figure 7-1.
NOTE: Always add a small amount of rosin flux or rosin-core
solder while resoldering connections.
After replacing or repairing
any printed circuit board or assembly,
perform the functional test in PART 3 of this manual to determine
proper operation of the repaired unit.
O. Replacing Resistors, Capacitors and Diodes
(1} Before removing diodes or polarized capacitors (electrolytics},
note polarity markings and orientation on circuit board.
(2} Using a small cutting tool (small diagonal cutter}, carefully
eut
off both component leads, leaving about 1/16 inch of lead
protruding
from circuit board. Remove component.
(3}
1
1.8. 21400C
PART 4
NOTE: If desired to disconnect only one lead for component
substitution (such as may be required during
troubleshooting}, refer to paragraph 4.0.(5}.
CAUTION: DO NOT APPLY HEAT AT A PLATED-THRU-HOLE FOR MORE
THAN 8 SECONDS. USE 20 TO 50 WATT SOLDERING IRON
ONLY.
Grasp a eut off lead (on component side of board} with small
needle-nosed pliers. Apply soldering iron (with a little flux
on the tip) to circuit board where lead passes through circuit
board. Track side can also be used. If track side is used for
unsoldering, ensure that the correct lead
and circuit board
point is located. As soon as solder melts, carefully remove
cutoff lead from component side. If excessive force is
applied, the plated-thru-hole may be pulled out of the board
with the lead.
5-8.1
Dec/92
The document reference is online, please check the correspondence between the online documentation and the printed version.

BENDIX/KING
MAINTENANCE MANUAL
IN-20258 MULTIFUNCTION COLOR INDICATOR
(4) Using soldering iron, reheat point on circuit board from which
a lead has been removed. When remaining solder melts, apply
and actuate solder sucker to remove solder. Repeat for
remaining lead. Use solder sucker as required until hales in
board are clean (as indicated by no solder on the walls, top,
or bottom of the hales in the circuit board).
NOTE: Final cleaning (in the circuit board) will be done just
prior to installing new component.
(5) If only one lead is being disconnected, for component
substitution during troubleshooting, proceed as follows:
1
1.8. 21400C
PART 4
(a) From component side, grasp lead close to circuit board
with small needle-nosed pliers.
(b) From track side of circuit board, heat point on circuit
board where lead passes through board. When solder melts,
carefully
lift lead upward until lead has cleared circuit
board.
(c) Repeat paragraph 4.0.(4} and ensure that all solder is
removed from hale.
5-8.2
Dec/92
The document reference is online, please check the correspondence between the online documentation and the printed version.