Technical description and composition of the SONY KD-55AF8 TV, panel type and modules used. The composition of the modules.
SONY LED
Model: KD-55AF8
Chassis / Version: MAIN BM2A
Panel: LE550AQP (EL) (A1)
T-CON: 6870C-0755B V18 VER1.0.0
LED driver (backlight): integrated into PSU
Power Supply (PSU): APS-422 1-983-477-13
PWM Power: PFC, PWM, MIP2H2 (STB)
MOSFET Power: N-FET TO-220F
MainBoard: 1-983-249-31
IC MainBoard: CPU, Scaler, eMMC, AUDIO, DC / DC
Tuner: CE553ZP
Control: WiFi: 1-458-998-11 J20H088
Specifications KD-55AF8
SONY KD-55AF8
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- SONY KD-55AF8 does not turn on and does not show any signs of operability at all. Does not blink indicators and does not respond to control buttons.
Most often, with similar manifestations, the main power module APS-422 is faulty. Its output voltages should be measured, and in their absence, check the serviceability of the power switches (N-FET TO-220F) of the converters and rectifier diodes for the probability of short circuit.
In case of breakdowns in the secondary circuits of the converter, it can usually work in an emergency mode in a short circuit mode, and with a short circuit in the power elements of the primary circuit, the mains fuse or current sensor in the source of the key is most often cut off.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying a PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) PFC, PWM, MIP2H2 (STB), in the absence of external damage and a short circuit between the terminals, are checked by replacing them with a known good one.
- There is no picture, but there is sound and reaction to commands from the remote control. Or the image appears immediately after switching on and disappears.
As a rule, in such cases there is no display backlight. The reason can be found in the malfunction of the LEDs, in the violation of the contact connections of the LED strips, or in the provision of their power supply (LED driver).
It should be remembered that it is not possible to determine a break in the LED lines without disassembling the panels using a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then you need to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow opening the LED in the forward direction or dual LEds are used, then the PN transition of the emergency zener diode can indirectly serve as an indicator of serviceability. In the event of a malfunction of the LED-a, the PN-junction of the Zener diode will either be cut off, or broken through in the SC.
In cases where the SONY KD-55AF8 does not have a picture, but there is sound, the display backlight often does not work.
In LED TVs, the LEDs inside the LE550AQP-ELA1 OLED panel are usually faulty, and less often the LED driver.
Without backlighting, sometimes you can see a barely noticeable image with a certain successful hit of external light on the screen.
Replacing the LEDs requires disassembling the LE550AQP-ELA1 panel. We do not recommend such works on their own to TV owners and craftsmen who do not have experience in repairing LCD panels, especially at home.
If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and on an open TV, the light can be seen through the holes in the panel case.
In this case, the T-CON (Timing Controller) board may be defective, but often the MainBoard 1-983-249-21 will also be defective. A software failure is also possible. The panel may also be faulty - damage to strips, loops, for example, after moisture. In such cases, first of all, it is necessary to check the panel supply voltage at the LVDS connector, fuses on the T-CON board or panel brackets, as well as supply and reference voltages for column and line drivers - VGH, VGL, Vcom.
If they are within normal limits, then the oscilloscope needs to track the passage of LVDS signals from MainBoard 1-983-249-21, as well as synchronizing signals to the loops with drivers.
Flooded screens of LED TVs can sometimes be repaired if no significant damage has formed in the loops and on the panel trims.
- The TV does not turn on, the indicator signals the standby or operating mode, or blinks.
Repair or diagnostics of the motherboard 1-983-249-31 should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its CPU, Scaler, eMMC, AUDIO, DC / DC chips and other possible faulty components. Malfunctions associated with BGA soldering technologies are usually easily diagnosed by the warm-up method.
If you suspect a malfunction of the CE553ZP tuner, first of all, you need to make sure that the software is correct, as well as the presence of the necessary levels of supply voltages and pulses of data exchange with the processor via the I2C bus at the corresponding tuner pins.
Owners of the KD-55AF8 TV are advised to contact only qualified specialists with the necessary work experience for repair! Attempts to repair yourself without the appropriate knowledge and skills can lead to irreversible negative consequences!
Additional MainBoard Repair
The appearance of MainBoard 1-983-249-31 is shown in the figure below:
1-983-249-31
External view of the power supply
APS-422:
APS-422
Main features of SONY KD-55AF8 device:
Installed matrix (LED panel) LE550AQP (EL) (A1).
Matrix control uses the 6870C-0755B Timing Controller (T-CON).
A converter combined with a power supply is used to power the backlight LEDs.
The formation of the necessary supply voltages for all nodes of the SONY KD-55AF8 TV is carried out by the APS-422 power module, or its analogs using PFC, PWM, MIP2H2 (STB) chips and N-FET TO-220F power switches.
MainBoard - the main board (motherboard) is a 1-983-249-31 module using CPU, Scaler, eMMC, AUDIO, DC / DC and others.
Tuner CE553ZP provides reception of television programs and tuning to channels.
Instructions and updates
Firmware update to version 6.6555:
File sony_dtvota_2016_1606555100_eua_auth.zip, version 6.6555 dated 04/22/2020 (1 886 350 011 bytes).
For models: KD43XG8305, KD49XG8305, KD49XG8377, KD43XG8388, KD49XG8388, KD43XG8396, KD49XG8396, KD43XG8399, KD49XG8399, KD49XG9005, KD55AG8, KD65AG8, KD43XG8096, KD49XG8096, KD55XG8096, KD65XG8096, KD75XG8096, KD43XG8196, KD49XG8196, KD55XG8196, KD65XG8196, KD65AF8, KD55AF8, KD75XF9005, KD65XF9005, KD55XF9005, KD49XF9005, KD65XF8796, KD55XF8796, KD49XF8796, KD43XF8796, KD65XF8599, KD55XF8599, KD49XF8599, KD43XF8599, KD85XF8596, KD75XF8596, KD65XF8596, KD55XF8596, KD49XF8596, KD43XF8596, KD65XF8588, KD55XF8588, KD49XF8588, KD43XF8588, KD65XF8577, KD55XF8577, KD49XF8577, KD43XF8577, KD65XF8505, KD55XF8505, KD49XF8505, KD43XF8505, KD70XF8305, KD60XF8305, KD55XF8096, KD49XF8096, KD43XF8096, KD65XF7596, KD55XF7596, KD49XF7596, KD43XF7596, KDL49WF805, KDL43WF805, KDL49WF804, KDL43WF804, KD77A1, KD65A1, KD55A1, KD75XE9405, KD65XE9305, KD55XE9305, KD75XE9005, KD65XE9005, KD55XE9005, KD49XE9005, KD75XE8596, KD65XE8599, KD65XE8596, KD65XE8588, KD65XE8577, KD65XE8505, KD55XE8599, KD55XE8596, KD55XE8588, KD55XE8577, KD55XE8505, KD55XE8396, KD55XE8096, KD49XE8396, KD49XE8099, KD49XE8096, KD49XE8088, KD49XE8077, KD49XE8005, KD49XE8004, KD43XE8396, KD43XE8099, KD43XE8096, KD43XE8077, KD43XE8005, KD43XE8004, KD100ZD9, KD75ZD9, KD65ZD9, KD49XD8305, KD43XD8305, KD55XD8005, KD49XD8005, KD43XD8005, KD49XD8077, KD43XD8077, KD49XD8088, KD43XD8088, KD49XD8099, KD43XD8099, KD65XD7504, KD65XD7505, KD55XD7004, KD49XD7004, KD55XD7005, KD49XD7005, KD50SD8005.
The update file and instructions can be downloaded from the manufacturer's website for the KD-55AF8 model.
Benefits and improvements of the latest update:
Improved TV turn-on time when exiting standby mode.
Guides and instructions are also offered for this model:
Reference Manual (Web Manual). Published on 13 Feb 2019.
Directory. Published on 21 May 2018, size 1.63 MB.
Wall-Mount Bracket. Published on 26 Apr 2018, size 9.7 MB.
Quick setup guide and quick start guide. Published on 25 Apr 2018, size 574 KB.
SONY KD-55AF8 TV with OLED-display LE550AQP-ELA1, diagonal size 54.6 "(139 cm) 16: 9 format. The screen in this model is made using modern OLED technology.
The LE550AQP-ELA1 sensor and MainBoard 1-983-249-21 software are capable of realizing the highest UHD image quality at 3840x2160 resolution in 4K UHD, HDR. Image processing is performed using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
The KD-55AF8 TV has built-in SMART software and pre-installed Android Operating System. Internet connection can be made via Wi-Fi wireless connection. Video processor supported media file formats: MP3, WMA, MPEG4, HEVC (H.265), Xvid, DivX, MKV, JPEG.
The power of the sound acoustic system 50 W (2x10 + 2x10 + 1x10 W) is provided by 5 speakers. Uses the NICAM stereo signal processing system and the Sound Surround function.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, HDMI x4, USB x3, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11ac, Miracast. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.
The power consumed in the operating mode from the network is 392 W. APS-422 power supply.
Dimensions: with stand 1226x717x255 mm, without stand 1226x712x55 mm.
TV weight: with stand: 22.2 kg, without stand: 18.7 kg.
Attention! LCD-panel LE550AQP-ELA1 OLED TV SONY KD-55AF8 is the most expensive element of it.
As far as possible, avoid mechanical impact and liquid spillage on the screen glass to avoid irreversible damage to the OLED panel!