Sunday 3 May 2020

REPAIR / SERVICING TV IZUMI TL19H213B

Technical description and composition of the IZUMI TL19H213B TV, type of panel and applicable modules. The composition of the modules.
Izumi
Model: TL19H213B
Chassis / Version: MST36
Panel: LM185WH1 (TL) (FC)
Inverter (backlight): LCD036C-19P1-2
PWM Inverter: OB3306QP (16)
MOSFET Inverter: ME4946 (8)
Trans Inverter: LA09 EFD20-612A
Power Supply (PSU): LCD036C-19P1-2
PWM Power: PWM SOT23-6 (K H1 35)
MainBoard: MST36-V1.2
IC MainBoard: TDA1517P, AP1934 (8) AP1534, CT3257A,
Tuner: CDT-3FP2I2-31
Technical Specifications TL19H213B
IZUMI TL19H213B
General recommendations for repairing TV LCD
It is advisable to start any repair and diagnostics of the IZUMI TL19H213B TV with a careful external examination of internal and external elements, including case parts, a display, buttons and cables. Any external damage can sometimes prompt the repairman to take further steps to determine the malfunction of the TV and localize the defect. Ring cracks in the soldering of the leads of the heating elements, swollen electrolytic capacitors, a charred paint layer on the resistors - all this for the repairman can be a hint in the assumptions about the causes and consequences of the malfunction.
Faults in the LCD036C-19P1-2 power supply module can be expressed in different ways, for example, the IZUMI TL19H213B does not turn on at all and the control lamps on its front panel do not light up and do not blink, and there are no signs of operability. If the mains fuse is broken in the power supply, in most cases a breakdown of the power switch is detected, which can be integrated with the PWM controller, or a separate field-effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
It should be remembered that the N-FET keys used in flyback converters rarely fail for no reason that must be sought by checking other elements of the circuit. Often the breakdown is caused by malfunctions of electrolytic capacitors or semiconductor elements in the primary circuit, or by a break in the resistors in the stabilization circuits. The PWM controller chip K H1 35 (6) can also cause a breakdown of the power switch of the converter.
In cases where the Power Factor Corrector (PFC) is used in the power supply, troubleshooting can be a bit more complicated.
If there is no image when IZUMI TL19H213B is turned on, or it appears for a second and disappears completely, but there is sound, most likely either the backlight lamps or their power converter (inverter) are faulty. It is necessary to check the electrolytic capacitors of the filter of the secondary rectifiers in the general power supply unit.
The operation of the power circuits of the inverter and the backlight in the normal mode are controlled by special protection, which is organized for fire safety, for example, to disconnect during short circuits or breaks in high-voltage connections or when the lamps are depressurized. This protection makes it difficult to diagnose and repair the inverter.
It should be remembered that when the protection is turned off, there is always a risk of failure of the power elements of the inverter during diagnosis. After repair, it is necessary to restore all standard converter protection circuits.
On the MST36-V1.2 motherboard, in case of a malfunction, you should first check the performance of all power supply stabilizers of the microcircuits and, if necessary, update the software (software). When repairing an MB board, you need to check its components TDA1517P, AP1934 (8) AP1534, CT3257A, tuner CDT-3FP2I2-31. Defective items should be replaced.
Owners and users of the IZUMI TL19H213B TV must remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!
Repair MainBoard
The appearance of the MainBoard MST36-V1.2 is shown in the figure below:
MST36-V1.2
MST36-V1.2 can be used in TVs:
ERISSON 24LJ10 (Panel V236H1-L01 ), ERISSON 15LJ30 (Panel LM156WH1), ERISSON 19LJ09 (Panel LM185WH1 (TL) (E6)), IZUMI TL15H102B (Panel M156NWR1), IZUMI TL19H213B (Panel LM185WH1 (TL)(FC)).
Main features of the IZUMI TL19H213B device:
The matrix (LCD panel) LM185WH1 (TL) (FC) is installed.
To power the backlight, an LCD036C-19P1-2 inverter is used, it is controlled by the OB3306QP PWM controller (16). A transformer LA09 EFD20-612A is installed in the inverter converter. As power elements of the inverter, keys of the type ME4946 (8) are used.
The necessary supply voltages for all nodes of the IZUMI TL19H213B TV are generated by the LCD036C-19P1-2 power supply module or its analogs using PWM SOT23-6 microcircuits (K H1 35).
MainBoard - the main board (motherboard) is an MST36-V1.2 module, using TDA1517P, AP1934 (8) AP1534, CT3257A, and others.
The tuner CDT-3FP2I2-31 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:

Brand: LG display
Model: LM185WH1-TLFC
Type: a-Si TFT-LCD, Panel
Diagonal size: 18.5 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 409.8x230.4 mm
Brightness: 250 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (6-bit + Hi-FRC)
Response Time: 5 (Tr + Td)
Frequency: 60Hz
Lamp Type: CCFL
Signal Interface: LVDS (1 ch, 8-bit)