Safety Instructions; Servicing Of Smds; Devices); General Cautions On Handling And Storage - Philips CDI 220/00 Service Manual

Compact disc interactive player
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3.1
SAFETY INSTRUCTIONS
- Safety regulations demand that the set be restored to
its original condition and that components identical
with the original types be used.
Safety components are marked by the symbol
A.
- ESD
JA
~
All IC's and many other semi-conductors are
susceptible to electrostatic discharges (ESD).
Careless handling during repair can reduce life
drastically.
When repairing, make sure that you are connected
with the same potential as the mass of the set via a
wrist wrap with resistance.
Keep components and tools also at this potential.
For detailed information see "Handling ESD-sensitive
components".
- A set to be repaired should always be connected to
the mains via a suitable isolating transformer.
- never replace any modules or any other parts while
the set is switched on.
- Use plastic instead of metal alignment tools. This in
order to prelude short-circuit or to prevent a specific
circuit form being rendered unstable.
3.2
SERVICING OF SMDs (Surface Mounted Devices)
3.2.1
General cautions on handling and storage
a. Oxidation on the SMDs terminals results in poor
soldering. Do not handle SMDs with bare hand.
b. Avoid for storage places that are sensitive to
oxidation such as places with sulfur or chlorine gas,
direct sunlight, high temperatures or a high degree of
humidity.
As a result the capacitance or resistance value of the
SMDs may be affected.
c. Rough handling of circuit boards containing SMDs
may cause damage to the components as well as the
circuit boards. Circuit boards containing SMDs should
never be bent or flexed. Different circuit board
materials expand and contract at different rates when
heated or cooled and the components and/or solder
connections may be damaged due to the stress.
Never rub or scrape chip components as this may
cause the value of the component to change. Similary,
do not slide the circuit board across any surface.
3.2.2
Removal of SMDs
a. Heat the solder (for 2-3 seconds) at each terminal of
the chip. Small components can, by means of litz wire
and a limited horizontal force, be removed with the
soldering iron. They can also be removed with a
solder sucker (see Fig.
1
a) or
b. While holding the SMD with a pair of tweezers take it
off gently using th soldering iron's heat applied to
each terminal (see Fig. 1 b).
c. Remove the excess solder on the solder lands by
means of litz wire or a solder sucker (see Fig. 1 c).
3.2.2.1
Caution on removal:
a. When handling the soldering iron, use suitable
pressure and be careful.
b. When removing the chip, do not use undue force with
the pair of tweezers.
c. The soldering iron to be used (approx. 30 W), must
preferably be provided with a thermal control
(soldering temperature about 225 to 250°C).
d The chip, once removed, must never be used again.
PCS 61850
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HEATING
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OR
A
a
HEATING
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SOLrJf.RlNG moN
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SOil..DER WlCKa;.t-n.. "~\ CLEANING
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Fig. 1
3.2.3
Attachment of SMDs
43
161
A.11
a. Locate the SMD on the solder lands by means of
tweezers and solder the component at one side.
Ensure that the component is positioned well on the
solder lands (see Fig. 2a).
b. Next complete te soldering of the terminals of the
component (see Fig. 2b).
MOUl'ITII\IG
Fig. 2
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,,.,.,..!RON
3.2.3.1
Caution on attachment:
Fig. 3
a. When soldering the SMD terminals, do not touch them
directly with the soldering iron. The soldering must be
as quick as possible; care must be taken to avoid
damage to the terminals and the body itself.
b. Keep the SMD's body in contact with the printed
board when soldering.
c. The soldering iron to be used (approx. 30 W) must
preferably be provided with a thermal control
(soldering temperature about 225 to 250°C).
d. Soldering should not be done outside the solder land.
e. Soldering flux (of rosin) may be used but should not
be acidic.
f. After soldering, let the SMD cool down gradually at
room temperature.
g. The quantity of solder must be proportional with the
size of the solder land. If the quantity is too great, the
SMD might crack or the solder lands might be torn
loose from the printed board (see Fig. 3).
TOOLS TO BE USED
ANTISTATIC MAT
MAGNIFYING GLASS
CUTTING
THE LEADS
HAIR ORYER
-------•···•··•"--
METAL BRUSH
DISMOUNTING
CLEANING
THE TRACKS
WRONG
TRACKSWlLL
BE DA.MAGED
ALIGNING THE LEADS
RIGHT
WRONG
WRONG
4822 390 50025
W
~ F L U X
BRUSH '
,,,,;,
4822 321 40042
OESOLDEA BRAIO
SOLDERING IRON
WELLER TCP 50
00,S-0,8 MM
FIXING IC
AT THE CORNERS
RIGHT
MOUNTING
DRYING
SOLDER TIP
WELLER PT-CC7
4822 310 50081
,,
"' ' " "'
:::
KNIFE
APPLYING FLUX
SOLDERING
WRONG
WRONG

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