Service Notes
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 ICs when removing. Usually applying heat to the component for a short time while twisting with tweezers will break the component loose.
Leadless Chip Component (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 chips capacitor or resistor board solder pads may have holes through the board, however the hole diameter limits standard resistor replacement to 1/8 watt. Standard capacitor may also be limited for the same reason. It is recommended that identical components be used.
Chip resistor have a three digit numerical resistance code - 1st and 2nd significant digits and a multiplier. Example: 162 = 1600 or 1.6kΩ resistor, 0 = 0Ω (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 terminal.
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.
TYPE | Chip Components | SOLDER | |
|
|
| |
| GRADE |
| CAPS |
|
|
| |
| c |
|
|
b |
|
|
|
| e | CAPACITOR |
|
| TRANSISTOR |
| |
1ST DIGIT | 2ND DIGIT |
How to Replace Flat-IC - Required Tools -
• | Soldering iron | • | |
• | Needle nose pliers | • | Magnifier |
• Wire cutters (sharp & small) |
|
| |
1.Cut the pins of a defective IC with wire cutters. Remove IC from board. If IC is glued to the board, heat the IC and release the IC. See Note above.
Flat IC
2.Using soldering iron and needle nose pliers remove the IC pins from the board.
Soldering
Iron
3.Using
Braid
Soldering
Iron
4.Position the new
Polarity | 2nd solder |
|
| |
1st solder | ||||
|
| |||
symbol |
|
|
|
Solder the pin opposite to pin #1. This will assist positioning the IC.
5.Solder all pins to the soldering pads using a fine tipped soldering iron.
COMMON
CATHODE
MULTIPLIER
Solder
Soldering Iron
=1600 = 1.6k
ANODES | SOLDER |
| CAPS |
MH DIODE | RESISTOR |
|
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
- 5 -
