Magnavox 20MC4304/17, Руководство по обслуживанию

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1-3-4 T1102_SN
2. Installation
1. Using desoldering braid, remove the solder from
the foil of each pin of the flat pack-IC on the CBA
so you can install a replacement flat pack-IC more
easily.
2. The “
●
” mark on the flat pack-IC indicates pin 1.
(See Fig. S-1-7.) Be sure this mark matches the 1
on the PCB when positioning for installation. Then
presolder the four corners of the flat pack-IC. (See
Fig. S-1-8.)
3. Solder all pins of the flat pack-IC. Be sure that
none of the pins have solder bridges.
Instructions for Handling Semi-
conductors
Electrostatic breakdown of the semi-conductors may
occur due to a potential difference caused by
electrostatic charge during unpacking or repair work.
1. Ground for Human Body
Be sure to wear a grounding band (1 M
Ω
) that is
properly grounded to remove any static electricity that
may be charged on the body.
2. Ground for Workbench
Be sure to place a conductive sheet or copper plate
with proper grounding (1 M
Ω
) on the workbench or
other surface, where the semi-conductors are to be
placed. Because the static electricity charge on
clothing will not escape through the body grounding
band, be careful to avoid contacting semi-conductors
with your clothing.
Example :
Pin 1 of the Flat Pack-IC
is indicated by a " " mark.
Fig. S-1-7
Presolder
CBA
Flat Pack-IC
Fig. S-1-8
<Incorrect>
CBA
Grounding Band
Conductive Sheet or
Copper Plate
1M
Ω
1M
Ω
<Correct>
CBA