LG Electronics L1733TR, L1933TR General Soldering Guidelines, IC Remove/Replacement, Removal

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General Soldering Guidelines

General Soldering Guidelines

1.Use a grounded-tip, low-wattage soldering iron and appropriate tip size and shape that will maintain tip temperature within the range or 500 F to 600 F.

2.Use an appropriate gauge of RMA resin-core solder composed of 60 parts tin/40 parts lead.

3.Keep the soldering iron tip clean and well tinned.

4.Thoroughly clean the surfaces to be soldered. Use a mall wire-bristle (0.5 inch, or 1.25cm) brush with a metal handle.

Do not use freon-propelled spray-on cleaners.

5.Use the following unsoldering technique

a.Allow the soldering iron tip to reach normal temperature.

(500 F to 600 F)

b.Heat the component lead until the solder melts.

c.Quickly draw the melted solder with an anti-static, suction-type solder removal device or with solder braid.

CAUTION: Work quickly to avoid overheating the circuitboard printed foil.

6.Use the following soldering technique.

a.Allow the soldering iron tip to reach a normal temperature (500 F to 600 F)

b.First, hold the soldering iron tip and solder the strand against the component lead until the solder melts.

c.Quickly move the soldering iron tip to the junction of the component lead and the printed circuit foil, and hold it there only until the solder flows onto and around both the component lead and the foil.

CAUTION: Work quickly to avoid overheating the circuit board printed foil.

d.Closely inspect the solder area and remove any excess or splashed solder with a small wire-bristle brush.

IC Remove/Replacement

Some chassis circuit boards have slotted holes (oblong) through which the IC leads are inserted and then bent flat against the circuit foil. When holes are the slotted type, the following technique should be used to remove and replace the IC. When working with boards using the familiar round hole, use the standard technique as outlined in paragraphs 5 and 6 above.

Removal

1.Desolder and straighten each IC lead in one operation by gently prying up on the lead with the soldering iron tip as the solder melts.

2.Draw away the melted solder with an anti-static suction-type solder removal device (or with solder braid) before removing the IC.

Replacement

1.Carefully insert the replacement IC in the circuit board.

2.Carefully bend each IC lead against the circuit foil pad and solder it.

3.Clean the soldered areas with a small wire-bristle brush. (It is not necessary to reapply acrylic coating to the areas).

"Small-Signal" Discrete Transistor

Removal/Replacement

1.Remove the defective transistor by clipping its leads as close as possible to the component body.

2.Bend into a "U" shape the end of each of three leads remaining on the circuit board.

3.Bend into a "U" shape the replacement transistor leads.

4.Connect the replacement transistor leads to the corresponding leads extending from the circuit board and crimp the "U" with long nose pliers to insure metal to metal contact then solder each connection.

Power Output, Transistor Device

Removal/Replacement

1.Heat and remove all solder from around the transistor leads.

2.Remove the heat sink mounting screw (if so equipped).

3.Carefully remove the transistor from the heat sink of the circuit board.

4.Insert new transistor in the circuit board.

5.Solder each transistor lead, and clip off excess lead.

6.Replace heat sink.

Diode Removal/Replacement

1.Remove defective diode by clipping its leads as close as possible to diode body.

2.Bend the two remaining leads perpendicular y to the circuit board.

3.Observing diode polarity, wrap each lead of the new diode around the corresponding lead on the circuit board.

4.Securely crimp each connection and solder it.

5.Inspect (on the circuit board copper side) the solder joints of the two "original" leads. If they are not shiny, reheat them and if necessary, apply additional solder.

Fuse and Conventional Resistor

Removal/Replacement

1.Clip each fuse or resistor lead at top of the circuit board hollow stake.

2.Securely crimp the leads of replacement component around notch at stake top.

3.Solder the connections.

CAUTION: Maintain original spacing between the replaced component and adjacent components and the circuit board to prevent excessive component temperatures.

Copyright 2007 LG Electronics. Inc. All right reserved.

LGE Internal Use Only

Only for training and service purposes

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Contents Same model for Service READ THE SAFETY PRECAUTIONS IN THIS MANUALCHASSIS NO. LM57B BEFORE SERVICING THE UNITSPECIFICATIONS CONTENTSWARNING FOR THE SAFETY-RELATEDCOMPONENT PRECAUTIONmarked on the schematic diagram and the Leakage Current Hot Check CircuitElectrostatically Sensitive ES Devices SERVICING PRECAUTIONSGeneral Servicing Precautions Replacement IC Remove/ReplacementSmall-SignalDiscrete Transistor Removal/ReplacementAt Other Connections Circuit Board Foil RepairAt IC Connections SYNC TIMING CHARTVIDEO Only for training and service purposes DISASSEMBLY-SetSoft pad on the table Pull up the stand partRemove the screws Only for training and service purposes1.Pull the front cover upward 3.Put the front face downIn case of Latch #1-1 DISASSEMBLY-StandDISASSEMBLY-Stand In case of Latch #1Only for training and service purposes Hold the stand bodyLIPS BLOCK DIAGRAMMStarACE Line BufferINVERTER BLOCK DIAGRAM-POWERPOWER 2.Power Part DESCRIPTION OF BLOCK DIAGRAM1.Video Controller Part 3.MICOM Part6.Signal collection LIPS Board Block DiagramPRIMARY Operation description LIPSADJUSTMENT Figure 1. Cable Connection SERVICE OSDWaveforms TROUBLESHOOTING GUIDE1. NO POWER 2. NO RASTER OSD IS NOT DISPLAYED - LIPS Waveforms 3. NO RASTER OSD IS NOT DISPLAYED - MSTARWaveforms 4. TROUBLE IN DPM5. POWER 6. Raster Only for training and service purposes WIRING DIAGRAMLGE Internal Use Only 6631900109ALGE Internal Use Only EXPLODED VIEWOnly for training and service purposes Description EXPLODED VIEW PARTS LISTRef. No SAFETY Mark REPLACEMENT PARTS LISTOnly for training and service purposes CAUTION: BEFORE REPLACING ANY OF THESE COMPONENTSLGE Internal Use Only Only for training and service purposesFILTERs TRANSISTORLGE Internal Use Only Only for training and service purposesCAPACITORS TRANSISTORs & ICsTRANSFORMER Only for training and service purposesLGE Internal Use Only 1. SCALER SCHEMATIC DIAGRAMOnly for training and service purposes LGE Internal Use OnlyLGE Internal Use Only 2. POWER & WAFEROnly for training and service purposes LGE Internal Use Only 3. INVERTEROnly for training and service purposes LGE Internal Use Only 4. POWEROnly for training and service purposes P/NO MFL43002807 Feb
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L1733TR, L1933TR specifications

LG Electronics has established itself as a prominent player in the display technology market, offering a diverse range of monitors catered to various user needs. Among their notable models are the L1733TR, L1753TR, L1953T, L1953TX, and L1933TR, each designed to deliver exceptional performance, vivid visuals, and ergonomic features ideal for both casual users and professionals.

The LG L1733TR and L1753TR models are 17-inch and 17-inch widescreen monitors respectively, boasting a resolution of 1280x1024 pixels. These monitors utilize a TFT LCD panel technology that results in outstanding clarity and color accuracy. With a quick response time, they are well-suited for gaming and video playback, reducing motion blur and ensuring a smooth viewing experience. The aspect ratio of 5:4 for L1733TR and 16:10 for L1753TR further enhances compatibility with a variety of applications, particularly those requiring precise graphics.

The L1953T and L1953TX models represent LG’s commitment to larger display solutions, featuring a 19-inch screen size. With a resolution of 1280x1024 pixels, these monitors deliver sharp images and vibrant colors, making them ideal for graphic design and multimedia tasks. The L1953TX variant includes an added feature of built-in speakers, allowing for an all-in-one multimedia experience without the need for external audio devices.

The L1933TR, another commendable entry in LG's lineup, exhibits a sleek design with a slim profile and narrow bezels, making it a contemporary choice for users keen on aesthetics. This 19-inch monitor uses advanced backlight technology to provide better energy efficiency and reduced power consumption compared to traditional LCDs. With a wide viewing angle, the L1933TR ensures consistent image quality from different perspectives, allowing for collaborative work and presentations.

In terms of connectivity, all models are equipped with a variety of input options including VGA and DVI, facilitating compatibility with an array of devices such as laptops and desktops. The inclusion of various ergonomic features such as adjustable stands and VESA mount compatibility enhances user comfort, making long hours of work less taxing on the body.

Overall, LG's L1733TR, L1753TR, L1953T, L1953TX, and L1933TR monitors exemplify the company’s dedication to providing innovative display solutions that combine cutting-edge technology with user-friendly features, catering to the diverse requirements of modern users.
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