Safety Instructions, Warnings, and NotesFTP2.2E AA2.EN 5
2. Safety Instructions, Warnings, and Notes
Index of this chapter:Service Default Mode (see chapter 5) with a colour bar
2.1 Safety Instructionssignal and stereo sound (L: 3 kHz, R: 1 kHz unless stated
2.2 Warningsotherwise) and picture carrier at 475.25 MHz for PAL, or
2.3 Notes61.25 MHz for NTSC (channel 3).
Where necessary, measure the waveforms and voltages
with () and without ( ) aerial signal. Measure the
2.1Safety Instructions
voltages in the power supply section both in normal
operation ( ) and in stand-by (
). These values are
Safety regulations require the following during a repair:indicated by means of the appropriate symbols.
Connect the set to the Mains (AC Power) via an isolation The semiconductors indicated in the circuit diagram and in
transformer (> 800 VA).the parts lists, are interchangeable per position with the
Replace safety components, indicated by the symbol , semiconductors in the unit, irrespective of the type
only by components identical to the original ones. Any indication on these semiconductors.
other component substitution (other than original type) may Manufactured under license from Dolby Laboratories.
increase risk of fire or electrical shock hazard.?Dolby?, ?Pro Logic? and the ?double-D symbol?, are
trademarks of Dolby Laboratories.
Safety regulations require that after a repair, the set must be
returned in its original condition. Pay in particular attention to
2.3.2 Schematic Notes
the following points:
Route the wire trees correctly and fix them with the
All resistor values are in ohms, and the value multiplier is
mounted cable clamps.
often used to indicate the decimal point location (e.g. 2K2
Check the insulation of the Mains (AC Power) lead for
indicates 2.2 kohm).
external damage.
Resistor values with no multiplier may be indicated with
Check the strain relief of the Mains (AC Power) cord for
either an "E" or an "R" (e.g. 220E or 220R indicates 220
proper function.
ohm).
Check the electrical DC resistance between the Mains (AC -6
All capacitor values are given in micro-farads (?= x10),
Power) plug and the secondary side (only for sets that have -9-12
nano-farads (n= x10), or pico-farads (p= x10).
a Mains (AC Power) isolated power supply):
Capacitor values may also use the value multiplier as the
1. Unplug the Mains (AC Power) cord and connect a wire
decimal point indication (e.g. 2p2 indicates 2.2 pF).
between the two pins of the Mains (AC Power) plug.
An "asterisk" (*) indicates component usage varies. Refer
2. Set the Mains (AC Power) switch to the "on" position
to the diversity tables for the correct values.
(keep the Mains (AC Power) cord unplugged!).
The correct component values are listed in the Spare Parts
3. Measure the resistance value between the pins of the
List. Therefore, always check this list when there is any
Mains (AC Power) plug and the metal shielding of the
doubt.
tuner or the aerial connection on the set. The reading
should be between 4.5 Mohm and 12 Mohm.
2.3.3 Rework on BGA (Ball Grid Array) ICs
4. Switch "off" the set, and remove the wire between the
two pins of the Mains (AC Power) plug.
Check the cabinet for defects, to prevent touching of any General
inner parts by the customer. Although (LF)BGA assembly yields are very high, there may
still be a requirement for component rework. By rework, we
mean the process of removing the component from the PWB
2.2Warnings
and replacing it with a new component. If an (LF)BGA is
removed from a PWB, the solder balls of the component are
All ICs and many other semiconductors are susceptible to deformed drastically so the removed (LF)BGA has to be
electrostatic discharges (ESD ). Careless handling discarded.
during repair can reduce life drastically. Make sure that,
during repair, you are connected with the same potential as Device Removal
the mass of the set by a wristband with resistance. Keep As is the case with any component that, is being removed, it is
components and tools also at this same potential. Available essential when removing an (LF)BGA, that the board, tracks,
ESD protection equipment: solder lands, or surrounding components are not damaged. To
- Complete kit ESD3 (small tablemat, wristband, remove an (LF)BGA, the board must be uniformly heated to a
connection box, extension cable and earth cable) 4822 temperature close to the reflow soldering temperature. A
310 10671. uniform temperature reduces the risk of warping the PWB.
- Wristband tester 4822 344 13999. To do this, we recommend that the board is heated until it is
Be careful during measurements in the high voltage certain that all the joints are molten. Then carefully pull the
section. component off the board with a vacuum nozzle. For the
Never replace modules or other components while the unit appropriate temperature profiles, see the IC data sheet.
is switched "on".
When you align the set, use plastic rather than metal tools.
Area Preparation
This will prevent any short circuits and the danger of a
When the component has been removed, the vacant IC area
circuit becoming unstable.
must be cleaned before replacing the (LF)BGA.
Removing an IC often leaves varying amounts of solder on the
2.3Notesmounting lands. This excessive solder can be removed with
either a solder sucker or solder wick. The remaining flux can be
removed with a brush and cleaning agent.
2.3.1 General
After the board is properly cleaned and inspected, apply flux on
the solder lands and on the connection balls of the (LF)BGA.
Measure the voltages and waveforms with regard to the
Note: Do not apply solder paste, as this has been shown to
chassis (= tuner) ground (), or hot ground (
), depending
result in problems during re-soldering.
on the tested area of circuitry. The voltages and waveforms
shown in the diagrams are indicative. Measure them in the |
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