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LetMeRepair UK Limited

LetMeRepair UK Limited

Our objectives in the United Kingdom are:

  • To offer our customers a central depot repair solution for the United Kingdom and Ireland
  • The repair focus in the UK facility, next to the expertise in LCD panel repair, is the whole unit repair of laptop, LCD TV, display and car navigation systems.
  • To offer the industry an alternative repair solution to our major competitors in the region. Healthy competition is a value add to all.

Our activities

Hotline:

  • Welcome desk, RMA management, carrier management with pick up service, 3rd level fault diagnosis and phone fix support.

FRU Level Repair: ( Full Replacement Unit )

  • Notebooks, PC's, LCD TV, Plasma TV, TFT Monitors

Main Board Repair: ( Printed Circuit Board Repair )

  • SMT level repairs on all electronic boards related to LCD TV,  Plasma TV and Display products

LCD Panel repair: ( Liquid Crystal Display )

  • LCD Panel repair for Notebooks, LCD TV, displays as well as all repairs related to PLASMA panels

Liquid Crystal Module (LCM) Repairs
TAB (Tape Automated Bonding)
TCP (Tape Carrier Package):
One of the most common functional failures found on LCD screens whether notebook or TV is horizontal and vertical line or block defects (see figures 1 & 2).

Although this can be attributed to number of different factors, including defective TFT’s and ITO (Indium Tin Oxide) corrosion, more commonly the line defect is the result of a defective TCP (Tape Carrier Package), or TAB as it is more commonly known. LETMEREPAIR personnel have many years of experience in this area and perform TAB repair on LCM’s ranging from 6.4 through to 46 inches in size. As well as TCP LetMeRepair are also well versed in emerging bonding technologies including both CoG (Chip on Glass) and CoF (Chip on Film). A brief overview of each can be found below.

CoF (Chip on Film):
COF

This technology is being employed ever more by manufacturers as a replacement for TCP. Since the turn of the century it has advanced rapidly with the evolution of Large Colour LCM’s, namely LCD TV’s. As seen in figure2 the external appearance of both differs little. From a repair perspective the COF TAB’s are more robust and can be recovered with more ease and greater success than traditional TCP’s. The ACF used to make the connection to the glass substrate is also selected specifically for each technology due to physical variances such as trace pitch, i.e. panel resolution.

CoG (Chip on Glass):

Chip on Glass technology was first introduced by OEM’s as a cost saving idea as it reduced the need for PCB’s and TCP’s given that the IC (Integrated Circuit) is bonded directly onto the glass substrate. Again, the connection is made using ACF that is specifically manufactured for this application.

FPC (Flexible Printed Circuit): All LCD panel manufacturers use a wide range of custom FPC designs as part of the LCD drive circuitry. Mostly the FPC’s are used to connect the Horizontal (Gate) driver PCBA to the Vertical (Source) driver PCBA. Depending on the OEM and LCD model type some connections are made via solder joints and others are made using ACF, similar to that of TCP bonding. A distorted display is a typical fault caused by a defective FPC and more often than not this can be repaired.

Front and Rear Polariser Replacement:

Using a wide range of repair equipment, some of which has been designed internally, LetMeRepair employs proven repair methods to remove and replace the Front and Rear Polariser films without causing damage to the LCM. The equipment can accommodate panels ranging from 6.4 to 45 inches in size. The replacement material is sourced from leading manufacturers in Asia and will be matched exactly to the original material ensuring the original image qualities are retained.

CCFL Replacement:

The CCFL (Cold Cathode Florescent Tube) is the item that provides the light to allow LCDs (Liquid Crystal Display) to be seen clearly. The CCFL is part of the diffuser/backlight assembly which also comprises of a reflector, light enhancement films, diffuser films and a plastic framework. Quantities of CCFL’s within LCD’s can vary from a single lamp in the small notebook LCDs to 20 or more lamps within the large screen TV LCDs. CCFL’s operate at voltages approaching 1Kv with initial start-up voltages approaching 2Kv and although the name suggests that these are cold, this is not the case. The high voltages and heat generation within the diffuser/backlight assembly can cause component failure within it and adjacent circuits around the LCD. Although the CCFL as an entity can be a similar length to that used in other LCD models, the rest of the diffuser/backlight assembly will most likely be unique to that specific LCD model number. LetMeRepair is able to replace the CCFL(s) within an LCD model providing the manufacturer has not bonded this into the assembly. The CCFL will be sourced from reputable lamp manufacturers and will be specified to deliver characteristics as close as possible to the LCD manufacturers original. This CCFL replacement is carried out within a clean area to minimise any contamination entering the LCD during the repair activity.

Component Level Debug:

Each LCD model has a circuit designed specifically by its manufacturer and used a number of propriety components that are not available on the open market. Interfacing of an LCD is dependant on the manufacturer’s specification and can require the use a variety of technologies to supply the required data and voltages to allow the LCD to function. If any of the supplied parameters are incorrect, the LCD will fail to operate correctly and the expected display will be flawed.

Due to our knowledge base built up as a result of many years within the LCD industry, LetMeRepair has the ability to trace the many circuits to identify the cause of failure and where possible replace the faulty component and allow the display to function again.

LetMeRepair has a wide variety of sources and has the ability to obtain cables, connectors and components to fit many various models of LCD ranging from 10.4 inch to 46 inch screens.

Plasma Display Panel (PDP) Repairs TAB (Tape Automated Bonding) TCP (Tape Carrier Package): The TCP can be replaced with new or salvaged parts from the same model of PDP. The TCP is a line driver IC on Polyimide or Kapton flex cable attached to the glass substrate and electrodes with ACF (Anisotropic Conductive Film). The old ACF is removed and the TCP refurbished to the highest levels to enable successful tacking and bonding using the specially developed  PDP bonder. PDP Screening The PDP can be screened as either a full unit or a disassembled module glass. Extended screening is used due to high number of temperature/time associated PDP faults. PDP Faults Burn In: - Where a faint image is retained on the display. Can be caused by a static image on the screen usually a channel number. Dead Line/Block: - A faulty TCP Noise/Dots: - An interference type fault can be caused by faulty boards, e prom or gas deterioration. No Display: - Faulty boards or gas discharged Board and Component Replacement With the high level of PDP repairs LetMeRepair holds a large number of spares available for most makes of PDP. If available the faulty part will be replaced with a fully functional module or component.

 
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