Technical description and composition of the AKAI LEA-32V24P TV, type of panel and modules used. Module composition.
AKAI LED
Model: LEA-32V24P
Chassis/Version: TP.VST59S.P89
Panel: T315XW04 V3 // ST315A04-5
LED backlight: HL-17320A28-0801S-01
LED driver (backlight): integrated into MainBoard
PWM LED driver: OB3350CP
MOSFET LED driver: TO-252
Power Supply (PSU): integrated into MainBoard
PWM Power: LD7536 (PWM SOT23-6 )
MOSFET Power: MDF7N60B
MainBoard: TP.VST59S.P89
IC MainBoard: CPU: TSUMV59XE-Z1, FLASH: W25Q32
CPU: R620D
Specifications LEA-32V24P
AKAI LEA-32V24P
General advice about LCD LED TV repair
Possible defects
- AKAI LEA-32V24P does not turn on, the buttons and remote does not respond, the indicators on the front panel are not lit or blinking.
In this case first of all you should check the functionality of the main power supply - AC/DC converter, all elements of which are located on the MainBoard TP.VST59S.P89. Then you should measure its output voltages and in case of their full or partial absence you should check the serviceability of power switches (MDF7N60B) and rectifier diodes of converters for possible short circuit.
If the semiconductors in the secondary circuits break down, the inverter can usually be short-circuited, and the mains fuse is often blown when a short circuit occurs in the primary circuit power elements.
Mos-Fet power switches used in switching power supplies sometimes fail due to the failure of some other element that can take it out of key mode, or create the maximum allowable parameters of the switch. These can be elements that feed the PWM controller, the frequency-retaining or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers LD7536 (PWM SOT23-6 ), in the absence of visible damage or outright short circuits between the pins are checked by replacing with new or known good.
- No picture, but there is sound and reaction to remote control commands. Or the image appears immediately after switching on and disappears.
Usually in such cases the defect is detected in the nodes of LED panel backlight. Often the cause of the malfunction is the lack of current in the chain of LEDs, such as their breakage or short circuit, or a violation of the contact connections of slots HL-17320A28-0801S-01.
It is impossible to detect a breakage in the line of LEDs without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their junctions you will need a voltage of several tens of volts. Ideally a current source would be suitable for this purpose. You can open up the panel and check each LED separately. Usually, Chinese multimeters will light up one 3 volt LED slightly if you connect the probes to it in the forward direction (red probe to the anode, black probe to the cathode). For twin 6-volt LEDs, the PN junction of its faulty regulator can be a good indicator. If the LED is faulty, its regulator will either be broken or it will be short-circuited.
If the AKAI LEA-32V24P has no picture but sound, often the T315XW04 V3 display backlight simply does not work. And, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases you may see a faintly visible image when external lighting strikes the screen.
Disassembly of the T315XW04 LCD Panel is required to replace the LED's, a process which requires the technician's experience and expertise. We strongly advise against performing this operation by yourself if you own the TV and if you are not an experienced LCD panel repair technician.
READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.
If there is no image, but backlighting works, the screen becomes a little lighter when the TV is switched on and you can see the light through the holes in the panel body when the TV is open.
In this case the panel may be defective - damage to the boards, cables, for example, as a consequence of moisture after an unsuccessful washing of the screen, the T-CON board (Timing Controller) may be defective. But it's not uncommon for the MainBoard TP.VST59S.P89 to be faulty as well, or for the software to be faulty as well.
The first thing to check is the panel supply voltage, fuses on the T-CON board, as well as the supply and voltage reference of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, you need to trace with an oscilloscope the LVDS signals from MainBoard TP.VST59S.P89, as well as synchronizing signals to the driver stubs.
Flooded or badly washed LED TV screens can be repaired in about half of all cases, usually if no significant damage has occurred to the panel stubs and strips.
- The LED blinks or lights constantly, the TV set does not turn on, the remote control does not respond.
Repair or diagnostic of the TP.VST59S.P89 motherboard begins with checking the regulators and power converters needed to power the chips and matrix. If necessary, software (firmware) should be updated or replaced. Board repair and chip replacement CPU: TSUMV59XE-Z1, FLASH: W25Q32 are made with the necessary equipment and the appropriate element base. Malfunctions associated with the use of soldering technology BGA processor can be localized by the heating method.
In case of the lack of tuning to the on-air or cable TV channels make sure that the software is correct, and also that the supply voltages on the R620D tuner pins correspond to the nominal ones. Also you have to check the presence of the tuner data exchange pulses with the processor via I2C bus with the help of an oscilloscope.
Once again, users must be reminded! Trying to repair your AKAI LEA-32V24P without proper skill and experience may result in its total unrepairability!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> Service manual and sсhematic diagram TP.VST59S.P89
Refinement after repair of the backlight. TP.VST59S.P89, OB3350CP. Information from the master.
To reduce the backlight current from 330 mA to 220 mA, I removed one of the low resistance 3.0 Ohm resistors in the driver current sensor on the TP.VST59S.P89 board. Located next to the LB802 coil.
Driver current limitation. TP.VST59S.P89, OB3350. Technical information
To reduce the backlight current in LED drivers with the popular OB3350CP (OB3350) controller, you must proportionally increase the total resistance of the current sensor - measuring low-resistance resistors from pin 5 (FB) to the body.
The TP.VST59S.P89 board has five resistors connected in parallel RB837 to RB842. Simply remove one or two of the resistors.
The driver may use the OB3350 chip. Then you can reduce the driver current with low impedance resistors in the LED circuit from the LED connector pins.
You can read & LEARN more below:
Many TV manufacturers are now installing a questionable thermal rating for the backlight LEDs, which has a negative effect on the longevity of the device. In half of the cases, LEDs fail after 2-3 years of operation due to overheating, usually seen by the destroyed phosphor on the body of the LEDs. The warranty period, as a rule, the LEDs still have time to work out.
Even if the maximum allowable current is within specifications the cooling of LEDs is not always sufficiently efficient, which can be seen by the traces of overheating, i.e. dark spots on textolite slats on the back side. And modern LED televisions use diodes with an external phosphor coating, which after a year or two crumbles and the crystal directly shines purple. How such a source of ultraviolet radiation can harm the health of users, no one has yet thought.
Chinese manufacturers via Aliexpress supplies diodes and LED strips in kits of any assortment, but the lucky owner of the TV pays for them and for the repair.
After replacing one or more faulty LEDs, it is useful to look at the rest carefully, if the phosphor is cracked, it is advisable to replace all the LEDs. If you measure the voltage drop on overheated LEDs, it will be slightly higher than that of adjacent less worn or new LEDs, which indirectly indicates the presence of a parasitic active resistance (ESR). Further operation of such LEDs is even more questionable.
If you reduce the current in the diodes, the power dissipation and the real operating temperature will decrease, then there is a chance that the old ones will still work.
Ways to limit the current in LED backlight drivers:
There is a lot of information on the Internet about ways to limit the current in the LED backlighting for different TVs and LED drivers. A lot of it is written plausibly but sometimes it is written by people far from electronics in order to publish any popular content on hot topics to boost web-sites ratings.
It's impossible to talk about each case separately within one article, because even similar models may have different panels and different boards with their own driver variants. But there are basic principles that are clear to craftsmen with even minimal knowledge and skill.
Other popular, complex and controversial current limit cases will be published as information becomes available.
There are three basic ways to reduce the backlight current.
1. By increasing the resistance of the LED current sensor - a low-resistance measuring resistor in the cathode (LED-) circuit.
2. Increasing the ratings of the resistors on the ISET (current setting) input of the LED driver chip.
3. changing the resistor ratings in the divider on the ADIM (Dimming) control input.
The fundamental difference between input ISET and ADIM is that ISET - input inverted, as FB, and ADIM - direct.
A PDF document from the manufacturer of the -----------> OB3350 is attached
READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.
More on MainBoard repairs
The MainBoard TP.VST59S.P89 is shown in the illustration below:
TP.VST59S.P89
The TP.VST59S.P89 motherboard is combined with a power supply module and is a standalone unit based on the TSUMV59Xx multifunction processor. The repair of such a card must begin with checking the power elements, as well as the efficiency of voltage converters and linear regulators, necessary to power certain processor parts, in particular: +1.2V core power supply, +1.8V on-board DDR memory and stand-by 3.3V stand-by unit. LCD panel supply voltage of 5V, or 12V depending on the type of panel used, is to be checked directly at the LVDS socket.
TP.VST59S.P89 can be used in televisions:
AKAI LEA-32A08G (Panel LC320EXN (SE)(E1)), AKAI LEA-28A08W (Panel ST2751A01-1), DEXP 32A3300 (Panel JHD315GH-E52), DNS H32A30 (Panel JHD315GH-E52), FUSION FLTV-32L42B (Panel KM315E3-CS-02), TELEFUNKEN TF-LED32S6 (Panel CX315DLEDM ST3151A05-5).
The main features of the device AKAI LEA-32V24P:
A matrix (LED panel) T315XW04 V3 or ST315A04-5 is installed.
A converter combined with the main board TP.VST59S.P89, controlled by a PWM controller OB3350CP, is used to power the backlight LEDs. A TO-252-type switch is used as a power element in the LED driver.
The power module is combined with MainBoard and is designed as reverse- path converter of AC/DC voltage with use of LD7536 (PWM SOT23-6 ) chips and MDF7N60B type power keys.
MainBoard - the main board (motherboard) is TP.VST59S.P89 module, with TSUMV59XE-Z1 CPU, W25Q32 FLASH and other microcircuits used.
The R620D tuner provides TV programme reception and channel tuning.
PWM SMPS in SOT-23-6, SOT-26, TSOP-6 packages
In
the circuitry of modern switching power supplies (SMPS), PWM
controllers made in small-sized planar packages with six terminals have
gained wide popularity. The enclosure type designation can be SOT-23-6,
SOT-23-6L, SOT-26, TSOP-6, SSOT-6. The appearance and arrangement of the
pins are shown in the figure below. In this case, the code marking
LD7530A is shown on the left fragment of the picture.
Pin assignment:
1 - GND. (Common wire).
2
- FB. (FeedBack - Feedback). Input for controlling the duration of
pulses with a signal from the output voltage. Sometimes it can be
labeled COMP (input comparator).
3 - RI / RT / CT / COMP / NC -
Depending on the type of microcircuit, it can be used for a
frequency-setting RC circuit (RI / RT / CT), or for organizing
protection, as an input of a PWM trip comparator at a threshold value at
its input, specified in the document. In some types of microcircuits,
this input may not be used in any way (NC - No Connect).
4 - SENSE, otherwise CS (Current Sense) - Input from the current sensor at the source of the key.
5 - VCC - Input voltage supply and start of the microcircuit.
6 - OUT (GATE) - Output for controlling the gate (Gate) of the key.
Functionally,
these regulators work on the principle of the previously popular xx384x
PWM microcircuits, which have proven themselves well in terms of
reliability and stability.
Some difficulties often arise when
replacing or choosing an analog for such PWM regulators due to the use
of code markings in the designation of the type of microcircuits. The
situation is complicated by a large number of component manufacturers
who do not always provide documentation to the mass access, just as not
all manufacturers of finished devices supply repair service centers with
diagrams, so repairmen often have to study real circuit solutions by
installed components and wiring connections directly on the board.
In
practice, PWM microcircuits and the marking code EAxxx and Eaxxx are
often found. Official documentation for them was not found in the public
domain, but discussions on the forums and pieces of pictures from PDF
from System General, which publishes them as SG6848T and SG6848T2, have
survived. The drawing is here placed left .
For the attention of the masters, here below are PDF datasheet tables
compiled from information available on the Internet and PDF documents
for the selection of analogues types when replacing the most common
six-legged planar PWM with pinout pins: pin1 - GND, pin2 - FB (COMP),
pin4 - Sense, pin5 - Vcc, pin6 - OUT ...
Their main difference is the application and purpose of pin 3.
| Name | Part Number | Fabricant | Marking |
|---|---|---|---|
| SG6849 | SG684965TZ | Fairchild / ON Semi | BBxx |
| SG6849 | SG6849-65T, SG6849-65TZ | System General | MBxx EBxx |
| SGP400 | SGP400TZ | System General | AAKxx |
PWM controllers (PWM) with a 95-100 kOhm resistor on pin 3.
When
applying the PWM listed below, the frequency should be set with the RT
(RI) resistor from pin 3 to ground. Usually its nominal value is chosen
95-100 kOhm for a frequency of 65-100 KHz. For more details, see the
here below attached documentation. PDF files are packed in RAR.
| Name | Part Number | Fabricant | Marking |
|---|---|---|---|
| AP3103A | AP3103AKTR-G1 | Diodes Incorporated | GHL |
| AP8263 | AP8263E6R, A8263E6VR | AiT Semiconductor | S1xx |
| AT3263 | AT3263S6 | ATC Technology | 3263 |
| CR6848 | CR6848S | Chip-Rail | 848H16 |
| CR6850 | CR6850S | Chip-Rail | 850xx |
| CR6851 | CR6851S | Chip-Rail | 851xx |
| FAN6602R | FAN6602RM6X | Fairchild / ON Semi | ACCxx |
| FS6830 | FS6830 | FirstSemi | |
| GR8830 | GR8830CG | Grenergy | 30xx |
| GR8836 | GR8836C, GR8836CG | Grenergy | 36xx |
| H6849 | H6849NF | HI-SINCERITY | |
| H6850 | H6850NF | HI-SINCERITY | |
| HT2263 | HT2263MP | HOT-CHIP | 63xxx |
| KP201 | Kiwi Instruments | ||
| LD5530 | LD5530GL LD5530R | Leadtrand | xxt30 xxt30R |
| LD7531 | LD7531GL, LD7531PL | Leadtrend | xxP31 |
| LD7531A | LD7531AGL | Leadtrend | xxP31A |
| LD7535/A | LD7535BL, LD7535GL, LD7535ABL, LD7535AGL | Leadtrend | xxP35-xxx35A |
| LD7550 | LD7550BL, LD7550IL | Leadtrend | xxP50 |
| LD7550B | LD7550BBL, LD7550BIL | Leadtrend | xxP50B |
| LD7551 | LD7551BL/IL | Leadtrend | xxP51 |
| LD7551C | LD7551CGL | Leadtrend | xxP51C |
| NX1049 | XN1049TP | Xian-Innuovo | 49xxx |
| OB2262 | OB2262MP | On-Bright-Electronics | 62xx |
| OB2263 | OB2263MP | On-Bright-Electronics | 63xx |
| PT4201 | PT4201E23F | Powtech | 4201 |
| R7731 | R7731GE/PE | Richtek | 0Q= |
| R7731A | R7731AGE | Richtek | IDP=xx |
| SD4870 | SD4870TR | Silan Microelectronics | 4870 |
| SF1530 | SF1530LGT | SiFirst | 30xxx |
| SG5701 | SG5701TZ | System General | AAExx |
| SG6848 | SG6848T, SG6848T1, SG6848TZ1, SG6848T2 | Fairchild / ON Semi | AAHxx EAxxx |
| SG6858 | SG6858TZ | Fairchild / ON Semi | AAIxx |
| SG6859A | SG6859ATZ, SG6859ATY | Fairchild / ON Semi | AAJFxx |
| SG6859 | SG6859TZ | Fairchild / ON Semi | AAJMxx |
| SG6860 | SG6860TY | Fairchild | AAQxx |
| SP6850 | SP6850S26RG | Sporton Lab | 850xx |
| SP6853 | SP6853S26RGB, SP6853S26RG | Sporton Lab | 853xx |
| SW2263 | SW2263MP | SamWin | |
| UC3863/G | UC3863G-AG6-R | Unisonic Technologies Co | U863 U863G |
| XN1049 | XN1049, XN1049TP | Innuovo Microelectronics | 49 xxx |
PWM controllers that use pin 3 differently.
When
using the following PWM (PWM controllers), you should pay attention to
pin 3, which can be used to organize protection - thermal or from
overvoltage of the input voltage.
The frequency can be fixed at 65kHz, or set by the value of the capacitor at pin 3.
When replacing any microcircuits with analogs, carefully study the documentation. PDF files are packed in a RAR archive.
| Name | Part Number | Fabricant | Marking |
|---|---|---|---|
| AP3105/V/L/R | AP3105KTR-G1, AP3105VKTR-G1, AP3105LKTR-G1, AP3105RKTR-G1 | Diodes Incorporated | GHN GHO GHP GHQ |
| AP3105NA/NV/NL/NR | AP3105NAKTR-G1, AP3105NVKTR-G1, AP3105NLKTR-G1, AP3105NRKTR-G1 | Diodes Incorporated | GKN GKO GKP GKQ |
| AP3125A/V/L/R | AP3125AKTR-G1, AP3125VKTR-G1, AP3125LKTR-G1, AP3125RKTR-G1 | Diodes Incorporated | GLS GLU GNB GNC |
| AP3125B | AP3125BKTR-G1 | Diodes Incorporated | GLV |
| AP3125HA/HB | AP3125HAKTR-G1, AP3125HBKTR-G1 | Diodes Incorporated | GNP GNQ |
| AP31261 | AP31261KTR-G1 | Diodes Incorporated | GPE |
| AP3127/H | AP3127KTR-G1, AP3127HKTR-G1 | Diodes Incorporated | GPH GSH |
| AP3301 | AP3301K6TR-G1 | Diodes Incorporated | GTC |
| FAN6862 | FAN6862TY | Fairchild / ON Semi | ABDxx |
| FAN6863 | FAN6863TY, FAN6863LTY, FAN6863RTY | Fairchild / ON Semi | ABRxx |
| HT2273 | HT2273TP | HOT-CHIP | 73xxx |
| LD7510/J | LD7510GL, LD7510JGL | Leadtrend | xxP10 xxP10J |
| LD7530/A | LD7530PL, LD7530GL, LD7530APL, LD7530AGL | Leadtrend | xxP30 xxxP30A |
| LD7532 | LD7532GL | Leadtrend | xxP32 |
| LD7532A | LD7532AGL | Leadtrend | xxP32A |
| LD7532H | LD7532HGL | Leadtrend | xxP32H |
| LD7533 | LD7533GL | Leadtrend | xxP33 |
| LD7536 | LD7536GL | Leadtrend | xxP36 |
| LD7536R | LD7536RGL | Leadtrend | xxP36R |
| LD7537R | LD7537RGL | Leadtrend | xxP37R |
| LD7539C GL | LD7539C GL | Leadtrend | xxP39C |
| ME8204 | ME8204M6G | MicrOne | ME8204xx |
| NCP1250 | NCP1250ASN65T1G, NCP1250BSN65T1G, NCP1250ASN100T1G, NCP1250BSN100T1G | ON Semiconductor | 25xxxx |
| NCP1251 | NCP1251ASN65T1G, NCP1251BSN65T1G, NCP1251ASN100T1G, NCP1251BSN100T1G | ON Semiconductor | 5xxxxx |
| OB2273 | OB2273MP | On-Bright-Electronics | 73xx |
| R7735 | R7735AGE, R7735HGE, R7735GGE, R7735RGE, R7735LGE | Richtek | |
| UC3873/G | UC3873-AG6-R, UC3873G-AG6-R | Unisonic Technologies | U873 U873G |
Further technical information about this panel:
Brand : AUO
Model : T315XW04 V3 CELL
Type : a-Si TFT-LCD, CELL
Diagonal size : 31.5 inch
Resolution : 1366x768, WXGA
Display Mode : AMVA, Normally Black, Transmissive
Active Area : 697.685x392.256 mm
Surface : Antiglare (Haze 2%), Hard coating (3H)
Glass Depth : 0.70+0.70 mm
Contrast Ratio : 3000:1
Display Colors : 16.7M (8-bit), CIE1931 72%
Response Time : 6.5 (G to G)
Frequency : 60Hz
Signal Interface : LVDS (1 ch, 8-bit), 30 pins
Voltage : 12.0V
AKAI LEA-32V24P TV with ST315A04-5 LCD display, measuring 32" (81cm) diagonally in a 16:9 aspect ratio. This model features Edge LED side illumination.
The ST315A04-5 LCD panel and MainBoard software TP.VST59S.P89 provide HD picture quality at 1366x768 resolution in 720p (HD Ready). Input antenna or video signals can be processed in PAL, SECAM, NTSC analogue systems. Graphical processing and digital signal formation is done in 480i, 480p, 576p, 720p standards. Supported multimedia file formats are MP3, JPEG.
The 16W (2x8W) audio output is provided by two speakers. NICAM STEREO audio processing system is used.
External interface (connection with other devices) is supported by standard input and output connectors: antenna input (RF), VGA, USB. A VGA (D-Sub 15) connector on the TV cabinet is used to connect a computer or notebook computer to the TV, the interface supports resolutions: 640x480, 800x600, 1024x768, 1360x768.
The TV set uses the power supply as part of the MainBoard.
Its dimensions are: 736x483x180mm.
Warning. The panel ST315A04-5 of AKAI LEA-32V24P LED TV is an expensive and unreliable element.
Avoid any kind of impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also not safe to splash liquid on the screen. Sometimes a single drop is enough if it drips down the glass onto the cables and the television becomes unrepairable.