Tuesday, 4 February 2020

REPAIR / SERVICING TV PHILIPS 55PFK7509

Technical description and composition of the PHILIPS 55PFK7509 TV, panel type and applicable modules. The composition of the modules.
PHILIPS LED
Model: 55PFK7509 / 12
Chassis / Version: TPM14.2E LA
Panel: LC550EUF-PGF1
T-CON: 6870C-0482A
LED driver (backlight): integrated into PSU
PWM LED driver: PF7900S, PF7702D
MOSFET LED driver: SM1F03NSFPC
Power Supply (PSU): 715G6385-P01-000-002E
PWM Power: LCS700LG, LD7752B, LD7591T
MOSFET Power: TK18A60V, TK13A65U
MainBoard: 715G6080-M0D-005K
IC MainBoard: MT5591, K9F4G08U0D, 24C128, KLM4G1FE3B, STA381BWTR, H5TQ4G63MFR
Tuner: SUT-PE231ZN
Appearance
PHILIPS 55PFK7509
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The PHILIPS 55PFK7509 TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
Most likely in this case, the main switching power supply (MPS) 715G6385-P01-000-002E is faulty. It is necessary to measure its output voltages, and in case of their absence, check the operability of the power switches of the converters and rectifier diodes for the probability of a short circuit.
In case of diode breakdowns in the secondary circuits, the converter can operate in emergency short-circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or 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, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM microcircuits are usually checked by replacement with new ones, or obviously working.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
A malfunction is usually most likely in these cases at the backlight nodes of the display matrix. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, black to the cathode). 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 turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the 715G6080-M0D-005K 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).
Before changing the SUT-PE231ZN tuner, if it is not possible to tune to television channels, make sure that there are supply voltages, which must be measured at the corresponding tuner terminals and checked for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Attention! For users and owners of 55PFK7509 TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-serviceability of the device.


Service manual and schematic diagram -------------------------->  PHILIPS Chassis TPM14.2E LA
 
40PFH6609/88, 40PFK6609/12, 40PFS6609/12, 40PFK6719/12, 40PFS6719/12, 42PFS7109/12, 42PFK7109/12, 42PFK7179/12, 42PFK7189/12, 47PFK6549/12, 47PFK6559/12, 47PFK6589/12, 47PFK7109/12, 47PFS7109/12, 47PFK7179/12, 47PFK7189/12

 The appearance of the MainBoard 715G6080-M0D-005K is shown in the figure below:
715G6080-M0D-005K
The appearance of the power supply
Main features of the PHILIPS 55PFK7509 device:
Installed matrix (LED panel) LC550EUF-PGF1.
The matrix control uses the Timing Controller (T-CON) 6870C-0482A.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by the PF7900S, PF7702D PWM controller. As the power elements of the LED driver, keys of the type SM1F03NSFPC are used.
The required supply voltages for all nodes of the PHILIPS 55PFK7509 television are generated by the 715G6385-P01-000-002E power module or its analogs using LCS700LG, LD7752B, LD7591T microchips and TK18A60V, TK13A65U power switches.
MainBoard - the main board (motherboard) is a module 715G6080-M0D-005K, using chips MT5591, K9F4G08U0D, 24C128, KLM4G1FE3B, STA381BWTR, H5TQ4G63MFR and others.
The SUT-PE231ZN tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC550EUF-PGF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 55 inch
Resolution: 1920x1080, FHD
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 1209.6x680.4 mm
Surface: Antiglare (Haze 1%), Hard coating (2H)
Brightness: 400 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M / 1.06B (8-bit / 8-bit + Dithering), CIE1931 72%
Response Time: 5 (G to G); 8 (MPRT)
Frequency: 120Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (2 ch, 8/10-bit), 92 pins
Voltage: 12.0V