Technical description and composition of the LG 40UF670V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 40UF670V
Chassis / Version: LD58H
Panel: HC400EQN-VCEQ2-212X
T-CON: IN8903A, H5TQ1G63EFR, 25Q16DVSIG, CM508, CM602
LED driver (backlight): with integrated PSU; 50V 1A
PWM LED driver: MC93F5616LB
MOSFET LED driver: 19NF20
Power Supply (PSU): EAX66205401 EAY63748601 LGP4043-15UL6
PWM Power: UC2843B, NR134S
MainBoard: EBU62961943 EBT63757309
IC MainBoard: LGE2136, MX25L8035E, LGE5352, MX25l3235E, TC58NVG0S3HTA00, NTP7515, 24G256
Tuner: TDJM-G301D EBL6156001
Specifications 40UF670V
LG 40UF670V
General repair guidelines for TV LCD LED
Possible manifestations of defects
- LG 40UF670V does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
In such cases, the EAX66205401 power supply is usually faulty. It is necessary to measure its output voltages and, if they are absent, to check the short circuit probability in the converters power switches and rectifier diodes.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And during short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) UC2843B, NR134S, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
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 enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the EBU62961943 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 LGE2136, MX25L8035E, LGE5352, MX25l3235E, TC58NVG0S3HTA00, NTP7515, 24G256. BGA chip malfunctions are usually easy to detect by warming up.
Before changing the tuner TDJM-G301D EBL6156001, if it is not possible to tune to television channels, make sure that there are supply voltages that need to be measured on the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
TV users and owners need to remember that attempts to self-repair an LG 40UF670V TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
Installed matrix (LED-panel) HC400EQN-VCEQ2-212X.
The matrix control uses the Timing Controller (T-CON) IN8903A.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by the MC93F5616LB PWM controller. As power elements of the LED driver, keys of the 19NF20 type are used.
The necessary supply voltages for all nodes of the LG 40UF670V TV are generated by the EAX66205401 power supply module or its analogs using UC2843B, NR134S microcircuits.
MainBoard - the main board (motherboard) is an EBU62961943 module, with the use of LGE2136, MX25L8035E, LGE5352, MX25l3235E, TC58NVG0S3HTA00, NTP7515, 24G256 chips, and others.
The TDJM-G301D EBL6156001 tuner provides TV reception and channel tuning.