Repair Tips - Philips VR120 Service Manual

5.3

Repair tips

5.3.1 Replacement procedure for leadless components (chip)
The following procedures are recommended for replacing
leadless components used in this unit.
1. Preparation for replacement
a. Soldering iron
Use a pencil-type soldering iron that uses less than 30W
b. Solder
Use Eutectic solder (Tin 63%, Lead 37%)
c. Soldering time
Maximum 4 seconds.
Note:
• Leadless components must not be re-used after removal.
• Excessive mechanical stress and rubbing of the
component electrode must be avoided.
2. Removing the leadless components
Grasp the leadless component body with tweezers and
alternately apply heat to both electrodes. When the solder on
both electrodes has melted, remove leadless component
with a twisting motion.
Note:
• Do not attempt to lift the component off the board until the
component is completely disconnected from the board
with a twisting motion.
• Be careful not to break the copper foil on the printed
circuit board.
Chip
Soldering iron
Figure 5-1
3. Installation of leadless components
a. Presolder the contact points on the circuit board
Presolder
Service modes, Repair tips
Tweezers
Soldering iron
VR120
b. Using tweezers press down the part and solder both
electrodes as shown below.
Note:
Do not glue the replacement component to the circuit board.
5.3.2 How to remove/install the Flat Pack IC
How to remove the Flat Pack IC
• Using a hot air Flat Pack IC unsoldering equipment
Figure 5-2
a. Prepare the hot air Flat Pack IC unsoldering equipment.
Then apply hot air to Flat Pack lC for 5 - 8 seconds.
b. Remove the Flat Pack lC with tweezers while applying the
hot air.
CAUTION:
To avoid damage, do not apply the hot air to the chip parts
around the Flat Pack lC for long periods.
C.B.A.
Masking
tape
Tweezers
Figure 5-3
Put masking tape around the Flat Pack lC to protect adjacent
parts.
The Flat Pack IC is fixed to the P.C.B. with glue; therefore
take care not to break or damage any foil under the lC or on
each pin when removing it.
5. GB 53
Tweezers
Soldering iron
Solder
EXAMPLE
Hot air Flat Pack
IC unsoldering
equipment
Flat Pack IC