Technical description and composition of the ERISSON 28LEP91 TV, type of panel and applicable modules. The composition of the modules.ERISSON LED
Model: 28LEP91
Chassis / Version: T.SIS231.T65
Panel: st2751a01-1
T-CON: mt3151a05-1-xc-7
MainBoard: T.SIS231.T65
IC MainBoard: Flash 25Q64
Specifications 28LEP91
ERISSON 28LEP91
General repair guidelines for TV LCD LED
Repair and diagnostics of any electronic device, in particular ERISSON 28LEP91, it is advisable to start with a careful external examination of internal and external elements. Specific external damage to some elements can sometimes indicate further actions to determine the malfunction of the TV and localize the defect before the necessary measurements are taken. Electrolytic capacitors of filters with a swollen casing, as well as ring cracks formed in the soldered leads of heating elements, or a layer of coal on burnt resistors sometimes tell the repairman the causes of the malfunction and possible consequences.
Sometimes the ERISSON 28LEP91 TV simply does not turn on. No control lights on the front panel are lit or blinking, the TV does not respond to the remote control and does not make any sounds or any signs of life when turned on. The most likely cause of the malfunction is a failure of the common power module. If it is working properly, you need to check the processor batteries on the SSB (Main Board). When diagnosing and repairing the power supply, after replacing the swollen capacitors of the secondary rectifier filters (if any), you must first check the mains fuse. When it is broken, the power elements of transistors and rectifier bridge diodes should be checked for avalanche (thermal) breakdown.
Mos-Fet keys used in switching power supplies (SMPS) rarely fail for no reason to look for when checking other circuit elements. 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 can also cause a breakdown of the power switch of the converter.
If the ERISSON 28LEP91 does not have an image, but there is sound and the TV is controlled by the remote control, a malfunction in the backlight circuits of the st2751a01-1 panel is likely. The LEDs or the power converter - LED driver may be faulty. Often in such cases, when you turn on the TV, an image appears and immediately disappears. First of all, it is necessary to verify the operability of the electrolytic capacitors of the rectifier filter supplying the LED driver, and check the LEDs, connecting obviously known good diagnostics.
Often there is a need for disassembling the panel to check the health of the LEDs, as well as contact connections in the connectors and soldering.
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.
If the T.SIS231.T65 motherboard is faulty, first of all it is necessary to check all the linear stabilizers or power converters of its chips, and also, if necessary, update the software. Sometimes you can check the health of MB only by replacement.
If it is not possible to replace the MB board (SSB), you need to check the health of its elements - Flash 25Q64. Defective components should be replaced.
Attention to users! Self-repair of the ERISSON 28LEP91 TV without the appropriate qualifications and experience can lead to its complete non-repairability!
FIRMWARE FOR SPI FLASH -----------> ERISSON 28LEP91 , Main: T.SIS231.T65, Panel: st2751a01-1
The appearance of MainBoard T.SIS231.T65 is shown in the figure below:T.SIS231.T65
T.SIS231.T65 can be used on TVs:
DNS M24DM8 (Panel M236HGE-L20 ReV.C1), DNS 22AE7000 (Panel CX215LEDM), ERISSON 28LEP91 (Panel st2751a01-1), ROLSEN RL-19E1501T2C (Panel V185BJ1-PE1), RUBIN RB-22SE5FT2C (Panel LM215DA-T01), RUBIN RB-22SE9FT2C (Panel M215HTN01.1), SHIVAKI STV-24LEDGR9 (Panel M236HGE-L20 Rev.C1), SHIVAKI STV-24LEDGW9 (Panel M236H3-LA3), SHIVAKI STV-24LED12 (Panel M236HGE-P01), THOMSON T24E09DU-01B (Panel V236BJ1-P03 (C1)).
Main features of the ERISSON 28LEP91 device:
Installed matrix (LED-panel) st2751a01-1.
The matrix control uses the Timing Controller (T-CON) mt3151a05-1-xc-7.
The required supply voltage for all nodes of the TV ERISSON 28LEP91 provides a switching power supply.
MainBoard - the main board (motherboard) is a T.SIS231.T65 module, using Flash 25Q64 chips and others.
Additional technical information about the panel:
Brand: CSOT
Model: ST2751A01-1
Type: a-Si TFT-LCD, CELL
Diagonal size: 27.5 inch
Resolution: 1366x768, WXGA
Display Mode: HVA, Normally Black, Transmissive
Active Area: 607.528x345.024 mm
Surface: Antiglare (Haze 2%), Hard coating (3H)
Glass Depth: 0.70 + 0.70 mm
Transmissivity: 7.2% (with Polarizer)
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 62%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
Trademark: ERISSON, Model: 28LEP91.
Shortly from the TV: LCD, 720p HD, diagonal 28 "(71 cm), there is USB, there is support for DVB-T2, backlight type: Edge LED.
The composition uses MainBoard T.SIS231.T65 and an LCD panel (matrix) st2751a01-1.
ERISSON 28LEP91 TV with a st2751a01-1 LCD display, diagonal size 28 "(71 cm) in 16: 9 format.
The LED-panel of this TV has LED backlighting - Edge LED. You can view images in high quality HD with a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported formats multimedia files: MP3, WMA, MPEG4, DivX , JPEG.
The power of the sound system 6 W (2x3 W) provide two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), component, SCART, VGA, USB. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-T2 standards.
Overall dimensions: With stand 439x300x138 mm, Without stand 439x263x44 mm.
Attention! The st2751a01-1 panel of the ERISSON 28LEP91 LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable.