Mitsubishi Electric DD-4020, Service Manual

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STANDARD NOTES FOR SERVICING
Circuit Board Indications
a. The output pin of the 3 pin Regulator ICs is indicated
as shown.
b. For other ICs, pin 1 and every fifth pin are indicated
as shown.
c. The 1st pin of every male connector is indicated as
shown.
Instructions for Connectors
1. When you connect or disconnect the FFC (Flexible
Foil Connector) cable, be sure to first disconnect the
AC cord.
2. FFC (Flexible Foil Connector) cable should be in-
serted parallel into the connector, not at an angle.
How to Remove / Install Flat Pack-IC
1. Removal
With Hot-Air Flat Pack-IC Desoldering Machine:
(1) Prepare the hot-air flat pack-IC desoldering ma-
chine, then apply hot air to the Flat Pack-IC (about
5 to 6 seconds). (Fig. S-1-1)
(2) Remove the flat pack-IC with tweezers while apply-
ing the hot air.
(3) Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
(4) Release the flat pack-IC from the CBA using tweez-
ers. (Fig. S-1-6)
Caution:
1. Do not supply hot air to the chip parts around the flat
pack-IC for over 6 seconds because damage to the
chip parts may occur. Put masking tape around the
flat pack-IC to protect other parts from damage.
(Fig. S-1-2)
2. The flat pack-IC on the CBA is affixed with glue, so
be careful not to break or damage the foil of each
pin or the solder lands under the IC when removing
it.
Hot-air
Flat Pack-IC
Desoldering
Machine
CBA
Masking
Tape
Tweezers
Flat Pack-IC
Fig. S-1-2
Fig. S-1-1
Top View
Out In
Bottom View
Input
5
10
Pin 1
Pin 1
FFC Cable
Connector
CBA
* Be careful to avoid a short circuit.
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