Technical description and composition of the LG LG27MT55S TV, panel type and applicable modules. The composition of the modules.LG LED
Model: LG27MT55S PZ
Chassis / Version: LD46E
Panel: LM270WF5 SLM1?
LED driver (backlight): integrated into MainBoard?
Power Supply (PSU): Adapter
MainBoard: EAX65648903 (1.1) EBR78619901
IC MainBoard: LGE2122, 42568RP, H5TQ2G63FFR, H5Q4G63AFRN, THGBM5G5A1JBAIR, R5F100GEA, NTP7513
Tuner: TDSQ-G601D (B)
Specifications 52LG5030
LG LG27MT55S
General repair guidelines for TV LCD LED
Possible malfunctions
- LG LG27MT55S TV does not turn on. The control lights do not light or flash. The TV does not respond to the remote control and buttons on the control panel.
Typically, with such manifestations, the defect is caused by faulty elements in the main power module.
The owner of the TV can purchase an external power supply unit such as Adapter and repairing it is not always advisable. In any case, the simplest typical defects characteristic of most IIP schemes can be easily detected and eliminated after opening. Then it is necessary to measure its secondary (output) voltages and, if they are absent, it is necessary to check the serviceability of power switches and rectifier diodes of the converters for a possible short circuit.
In case of breakdowns of the diodes in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. The PWM chip can also cause a malfunction of the power switch of the converter and is usually checked by replacement.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
The most likely in these cases is a malfunction of the LED backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX65648903 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements LGE2122, 42568RP, H5TQ2G63FFR, H5Q4G63AFRN, THGBM5G5A1JBAIR, R5F100GEA, NTP7513. BGA chip malfunctions are usually easy to detect by warming up.
If the TV works normally from external devices, but does not tune into television channels, the TDSQ-G601D (B) tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Once again, remind users! Attempts to self-repair the LG LG27MT55S TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
LG Display LM270WF5-SLM1 Datasheet Specification
The appearance of the MainBoard EAX65648903 is shown in the figure below:EAX65648903
Main features of the device LG LG27MT55S:
Installed matrix (LED-panel) LM270WF5 SLM1?.
To power the backlight LEDs, a converter is used, combined with the main board EAX65648903.
To power all the internal components of the LG LG27MT55S TV, an external adapter type source is used.
MainBoard - the main board (motherboard) is an EAX65648903 module using LGE2122, 42568RP, H5TQ2G63FFR, H5Q4G63AFRN, THGBM5G5A1JBAIR, R5F100GEA, NTP7513 and other chips.
The TDSQ-G601D (B) tuner allows you to receive television programs and tune to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LM270WF5-SLM1
Type: a-Si TFT-LCD, Panel
Diagonal size: 27.0 inch
Resolution: 1920x1080, FHD
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 597.888x336.312 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 250 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 72%
Response Time: 14 (G to G)
Frequency: 60Hz
Lamp Type: 14S3P WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V
