Panasonic CT-2707DF Service Manual

Also see for CT27D12DF - 27" COLOR TV: Operating instructions

Contents

Panasonic CT-2707DF Service Manual Manual pdf 5 page image

- 5 - Service ManualService NotesLeadless Chip Component(surface mount)Chip components must be replaced with identical chipsdue to critical foil track spacing. There are no holes inthe board to mount standard transistors or diodes.Some chips capacitor or resistor board solder padsmay have holes through the board, however the holediameter limits standard resistor replacement to 1/8watt. Standard capacitor may also be limited for thesame reason. It is recommended that identicalcomponents be used.Chip resistor have a three digit numerical resistancecode - 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 valueindicated on the capacitor. The color of the componentindicates the general range of the capacitance.Chip transistors are identified by a two letter code. Thefirst letter indicates the type and the second letter, thegrade of transistor.Chip diodes have a two letter identification code as perthe code chart and are a dual diode pack with eithercommon anode or common cathode. Check the partslist for correct diode number.Component Removal1. Use solder wick to remove solder from componentend caps or terminal.2. Without pulling up, carefully twist the componentwith tweezers to break the adhesive.3. Do not reuse removed leadless or chipcomponents since they are subject to stressfracture during removal.Chip Component Installation1. Put a small amount of solder on the boardsoldering pads.2. Hold the chip component against the solderingpads with tweezers or with a miniature alligator clipand apply heat to the pad area with a 30 watt ironuntil solder flows. Do not apply heat for more than3 seconds.How to Replace Flat-IC- Required Tools -1. Cut the pins of the defective IC with the wire cutterspliers, and remove it completely away from theboard. If the IC is glued to the board, apply hot airto complete the removal. CAUTION- Do not pull ortwist the pliers, may damage the soldering pads inthe board.2. Using the Soldering Iron and the long nose pliers,remove the IC pins that still attached to the board.3. Using the De-solder braid and the Soldering Iron,remove the solder from the board soldering pads.4. Position the new Flat-IC in place (apply the pins ofthe Flat-IC to the soldering pads where the pinsneed to be soldered). Properly determine thepositions of the soldering pads and pins bycorrectly aligning the polarity symbol. Start aligningand soldering Pin No.1, then align and solder thepin in the apposite corner of the IC, this will help toalign the rest of the pins.5. Solder all pins to the soldering pads using a finetipped soldering iron.6. Check with a magnifier for solder bridge betweenthe pins or for dry joint between pins and solderingpads. To remove a solder bridge, use a de-solderbraid as shown in the figure below.Note: These components are affixed with glue. Be careful not to break or damage any foil under thecomponent or at the pins of the ICs when removing. Usually applying heat to the component for ashort time while twisting with tweezers will break the component loose.Chip Components• Soldering iron • De-solder braids• Sharpen pliers (wirecutters and long nose)• MagnifierFlat-ICSolderingIronDe-SolderBraidSolderingIronPolaritySymbolSolderingIronSolderDe-SolderBraidSolderBridge SolderingIron