Technical description and composition of the DAEWOO L32S650VHE TV, type of panel and applicable modules. The composition of the modules.DAEWOO LED
Model: L32S650VHE
Chassis / Version: HK-T.RT2957P63
Panel: HK315LEDM-MH16H
LED backlight: HK32D10A-ZC21A-03 303HK320031
LED driver (backlight): integrated into MainBoard
PWM LED driver: 8 pin
MOSFET LED driver: TO-252
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MOSFET Power: TO-252
MainBoard: HK-T.RT2957P63
IC MainBoard: CPU: RTD2957M, SPI FLASH: 25Q64CS1Q
Tuner: NoName DVB-T2
Appearance
DAEWOO L32S650VHE
General repair guidelines for TV LCD LED
Possible manifestations of defects
- DAEWOO L32S650VHE TV does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
The malfunction in such cases, first of all, should be sought in the power elements of a switching power supply (IIP) - a network voltage converter (AC / DC), which in this TV model is combined with the MainBoard HK-T.RT2957P63 main board. It is necessary to measure its output supply voltages, and in case of their absence, check the operability of the power switches (TO-252) of the converters and rectifier diodes for the probability of breakdown in PN semiconductor junctions.
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 with a 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) PWM SOT23-6, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, the screen is black, there is sound, with external illumination of the screen, you can sometimes see barely noticeable outlines of the image.
In some of these cases, the malfunction is caused by a lack of backlighting on the display. Often the cause is a malfunction of the LEDs (open circuit, short circuit ...), or the connectors of the strips (strings), less often the LED driver is malfunctioning.
When diagnosing, it is necessary to take into account that it is impossible to check the open in the chain of LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally, a current source. By opening the panel, each LED can be checked separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect probes in the forward direction to it. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- 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 motherboard HK-T.RT2957P63 should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). When repairing an MB board, you need to check its CPU components: RTD2957M, SPI FLASH: 25Q64CS1Q. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
Before changing the NoName DVB-T2 tuner, if there is no possibility of tuning to television channels, you should make sure that there are supply voltages that must be measured at the corresponding tuner pins and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Attention TV owners! Self-repair attempts by DAEWOO L32S650VHE are not recommended by the manufacturer and can lead to serious negative consequences!
FIRMWARE FOR SPI FLASH -----------> DAEWOO L32S650VHE, Main: HK-T.RT2957P63, Panel: HK315LEDM-MH16H
The appearance of the MainBoard HK-T.RT2957P63 is shown in the figure below:HK-T.RT2957P63
Main features of the DAEWOO L32S650VHE device:
The matrix (LED panel) HK315LEDM-MH16H is installed.
To power the backlight LEDs, a converter is used, combined with the main board HK-T.RT2957P63, controlled by an 8 pin PWM controller. As power elements of the LED driver, keys of the TO-252 type are used.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using PWM SOT23-6 microcircuits and TO-252 type power switches.
MainBoard - the main board (motherboard) is an HK-T.RT2957P63 module, using CPU chips: RTD2957M, SPI FLASH: 25Q64CS1Q and others.
Tuner NoName DVB-T2 provides the reception of television programs and tuning to channels.