Hitachi 36UX59B Service Manual page 7

1 MSLXU
NOTE: These components are affixed with glue. Be careful not to break or damage any foil under the
component or at the pins of the /Cs when removing. Usually applying heat to the component for a short
time while twisting with tweezers will break the component loose.
Leadless Chip Components
(surface mount)
Chip components must be replaced with identical chips due to
critical foil track spacing. There are no holes in the board to
mount standard transistors or diodes. Some chip capacitor or
resistor board solder pads may have holes through the board,
however the hole diameter limits standard resistor replacement
to l/8 watt. Standard capacitors may also be limited for the
same reason. It is recommended that identical chip components
be used.
Chip resistors have a three digit numerical resistance code -1st
and 2nd significant digits and a multiplier. Example: 162 = 1600
or 1.6KSZ resistor, 0 = OQ (jumper).
Chip capacitors generally do not have the value indicated on the
capacitor. The color of the component indicates the general
range of the capacitance.
Chip transistors are identified by a two letter code. The first
letter indicates the type and the second letter, the grade of
transistor.
Chip diodes have a two letter identification code as per the code
chart and are a dual diode pack with either common anode or
common cathode. Check the parts list for correct diode number.
Component Removal
1. Use solder wick to remove solder from component end caps
or terminals.
2. Without pulling up, carefully twist the component with
tweezers to break the adhesive.
3. Do not reuse removed leadless or chip components since
they are subject to stress fracture during removal.
Chip Component Installation
1. Put a small amount of solder on the board soldering pads.
2. Hold the chip component against the soldering pads with
tweezers or with a miniature alligator clip and apply heat to
the pad area with a 30 watt iron until solder flows. Do not
apply heat for more than 3 seconds.
Chip Components
TYPE.
TRANSISTOR
1ST DIGIT
MH DIODE RESISTOR
How to Replace Flat-IC
-Required Tools-
* Soldering iron
l
iron wire or small awl
l
De-solder braids
l
Magnifier
1.
Remove the solder from all of the pins of a Flat-IC by using
a de-solder braid.
De-Solder
Braid
Soldering
Iron
2. Put the iron wire under the pins of the Flat-IC and pull it in the
direction indicated while heating the pins using a soldering
iron. A small awl can be used instead of the iron wire.
Iron
Wire
Awl
3.
4.
5.
Remove the solder from all of the pads of the Flat-IC by
using
a de-solder braid.
Position the new Flat-IC in place (apply the pins of the Flat-
IC to the soldering pads where the pins need to be soldered).
Properly determine the positions
of the soldering pads and pins by
Polarity Symbol
,
correctly aligning the polarity
symbol.
...
Solder all pins to the soldering pads using a fine tipped sol-
derino iron.
lering
'on
6. Check with a magnifier for solder bridge between the pins or
for dry joint between pins and soldering pads. To remove a solder
bridge, use a de-solder braid as shown in the figure below.
Bridge
Solder
Soldering
Iron
7