REPAIRING AND NOT THROWING AWAY

REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

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Friday, 27 December 2019

REPAIRING / SERVICING TV SAMSUNG LE40D503F7W

Technical description and composition of the SAMSUNG LE40D503F7W TV, panel type and applicable modules. The composition of the modules.
SAMSUNG
Model: LE40D503F7W LE40D503F7WXRU
Chassis / Version: U56G
Panel: LTF400HM05
T-CON: 400HR42S4LV.B; LQF6041T0B-Q1, SM4109, 24C64, ICL24835
Inverter (backlight): SST400_08A01
PWM Inverter: BD9275F
MOSFET Inverter: MDD3752
Power Supply (PSU): BN44-00469B
PWM Power: FSGM0465R, FAN7930B (PFC)
MOSFET Power: 10NM60N, 5N52U, MDS1653
MainBoard: BN41-01702A BN94-04845H
IC MainBoard: K4B1G1646G-BCH9, AT24C256C, 25X40BVSIG, Flash NAND: KFG1GN6W2D (BGA), LVC244A, DRV612, NTP-7411S;
Tuner: BN40-00220A
Control: Remote: AA59-00496A, IR: BN96-18311D BN41-01645A
Specifications LE40D503
SAMSUNG LE40D503F7W
General repair guidelines for TV LCD
Possible malfunctions
- SAMSUNG LE40D503F7W does not turn on. There are no signs of operability. The indicators on the front panel do not light or flash, the TV does not respond to the remote control and control buttons.
Most often, with such manifestations, the main power module BN44-00469B is found to be faulty. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches (10NM60N, 5N52U, MDS1653) and rectifier diodes in the converters for a short circuit.
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.
The breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency-setting or damper ones, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM) FSGM0465R, FAN7930B (PFC), if they do not have visible damage to the case and open short circuit between the terminals, are usually checked by replacement.
- There is no image, there is sound, it responds to the remote. Or the image may appear for a second when turned on and immediately disappears.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or inverter. If all the electrolytic capacitors of the filter for the power supply of the inverter are working, make sure that the lamps are working, then you need to check the converter keys and the secondary windings of the transformers.
Sometimes, for diagnostic purposes, inverter protection must be disabled. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the BN41-01702A motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, you should update or replace the software (software). In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its chips K4B1G1646G-BCH9, AT24C256C, 25X40BVSIG, Flash NAND: KFG1GN6W2D (BGA), LVC244A, DRV612, NTP-7411S; and other possible malfunctioning components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the tuner BN40-00220A. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
Attention TV owners! Attempts to self-repair SAMSUNG LE40D503F7W are not recommended by the manufacturer and can lead to serious negative consequences!


The appearance of the MainBoard BN41-01702A is shown in the figure below:
BN41-01702A
BN41-01702A can be used in TVs:
SAMSUNG LE40D503F7W LE40D503F7WXRU (Panel LTF400HM05), SAMSUNG UE32D4003BW UE32D4003 (Panel LTJ320AP02-L), SAMSUNG UE40D5003 UE40D5003BW (Panel LD400B2402403 Panel U4002G2EBDUE UD40E2BDUEE
PSU Advanced
The LE40D503F7W TV is equipped with a BN44-00469B power module using the PFC (Power Factor Correction) scheme acting as an active filter to eliminate the higher harmonic components of the current consumption. The boost converter based on the FAN7930B PWM controller does not allow the input rectifier filter's electrolytic capacitor to be connected to the network directly through open diodes, when the charge current determines its reactance (about 15-30 ohms at a frequency of 50 Hz). As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.
The appearance of the power supply
Main features of the SAMSUNG LE40D503F7W device:
Installed matrix (LCD panel) LTF400HM05.
The matrix control uses the Timing Controller (T-CON) 400HR42S4LV.B ;.
To power the backlight, an inverter SST400_08A01 is used, it is controlled by the BD9275F PWM controller. As power elements of the inverter, keys of the MDD3752 type are used.
The necessary supply voltages for all nodes of the TV SAMSUNG LE40D503F7W are generated by the power module BN44-00469B, or its analogs using microchips FSGM0465R, FAN7930B (PFC) and power switches of the type 10NM60N, 5N52U, MDS1653.
MainBoard - the main board (motherboard) is a BN41-01702A module, using microcircuits K4B1G1646G-BCH9, AT24C256C, 25X40BVSIG, Flash NAND: KFG1GN6W2D (BGA), LVC244A, DRV612, NTP-7411S; and others.
The tuner BN40-00220A provides the reception of television programs and tuning to channels.
Posted By: FRANK at 09:46
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