Safety Instructions, Warnings, and Notes
2.
2.4.2
Schematic Notes
•
All resistor values are in ohms, and the value multiplier is
often used to indicate the decimal point location (e.g. 2K2
indicates 2.2 kohm).
•
Resistor values with no multiplier may be indicated with
either an "E" or an "R" (e.g. 220E or 220R indicates 220
ohm).
•
All capacitor values are given in micro-farads (
μ=
x10
-6
),
nano-farads (n= x10
-9
), or pico-farads (p= x10
-12
).
•
Capacitor values may also use the value multiplier as the
decimal point indication (e.g. 2p2 indicates 2.2 pF).
•
An "asterisk" (*) indicates component usage varies. Refer
to the diversity tables for the correct values.
•
The correct component values are listed in the Spare Parts
List. Therefore, always check this list when there is any
doubt.
2.4.3
Lead-free Soldering
Due to lead-free technology some rules have to be respected
by the workshop during a repair:
•
Use only lead-free soldering tin Philips SAC305 with order
code 0622 149 00106. If lead-free solder paste is required,
please contact the manufacturer of your soldering
equipment. In general, use of solder paste within
workshops should be avoided because paste is not easy to
store and to handle.
•
Use only adequate solder tools applicable for lead-free
soldering tin. The solder tool must be able:
–
To reach a solder-tip temperature of at least 400°C.
–
To stabilize the adjusted temperature at the solder-tip.
–
To exchange solder-tips for different applications.
•
Adjust your solder tool so that a temperature of around
360°C - 380°C is reached and stabilized at the solder joint.
Heating time of the solder-joint should not exceed ~ 4 sec.
Avoid temperatures above 400°C, otherwise wear-out of
tips will increase drastically and flux-fluid will be destroyed.
To avoid wear-out of tips, switch “off” unused equipment or
reduce heat.
•
Mix of lead-free soldering tin/parts with leaded soldering
tin/parts is possible but PHILIPS recommends strongly
to
avoid
mixed regimes. If this cannot be avoided, carefully
clear the solder-joint from old tin and re-solder with new tin.
2.4.4
Alternative BOM identification
In September 2003, Philips CE introduced a change in the way
the serial number (or production number, see Figure 2-2) is
composed. From this date on, the
third digit
in the serial
number (example: AG
2
B0335000001) indicates the number of
the alternative BOM (Bill of Materials used for producing the
specific model of TV set). It is possible that the same TV model
on the market is produced with e.g. two different types of
displays, coming from two different O.E.M.s.
By looking at the third digit of the serial number, the service
technician can see if there is more than one type of B.O.M.
used in the production of the TV set he is working with. He can
then consult the At Your Service Web site, where he can type
in the Commercial Type Version Number of the TV set (e.g.
28PW9515/12), after which a screen will appear that gives
information about the number of alternative B.O.M.s used.
If the third digit of the serial number contains the number 1
(example: AG
1
B033500001), then there is only one B.O.M.
version of the TV set on the market. If the third digit is a 2
(example: AG
2
B0335000001), then there are two different
B.O.M.s. Information about this is important for ordering the
correct spare parts!
For the third digit, the numbers 1...9 and the characters A...Z
can be used, so in total: 9 plus 26 = 35 different B.O.M.s can
be indicated by the third digit of the serial number.
2.4.5
Practical Service Precautions
•
It makes sense to avoid exposure to electrical shock.
While some sources are expected to have a possible
dangerous impact, others of quite high potential are of
limited current and are sometimes held in less regard.
•
Always respect voltages
. While some may not be
dangerous in themselves, they can cause unexpected
reactions that are best avoided. Before reaching into a
powered TV set, it is best to test the high voltage insulation.
It is easy to do, and is a good service precaution.
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