Repair practice
Like
Social buttons
TV Toshiba 32w3453r
A TV came in for repair with the following fault:
“Does not turn on”, “No image”
External inspection shows the absence of matrix backlight.
The parts were opened and inspected.
The matrix has been opened. Testing showed a malfunction of the LEDs in each of the backlight lines. All LEDs have been replaced:
LED characteristics are similar to the article on repairing LG 32LN540V:
- forward current: 400mA
- Pulse Forward Current: 650mA
- Reverse Current: 25mA
- Reverse Voltage(VR): 0.8-1.2V(mA)
- Power Dissipation (PD): 1460 MW
- Forward voltage: 3.05-3.65 V
In this model, the tapes are glued with tape; after soldering, they need to be glued so that the tapes fit more tightly to the body for better cooling of the LEDs. We glue it with the old reliable BF-2 - it withstands temperature loads well.
For good pressure when gluing, I found the magnets from the magnetic shafts of the cartridges very useful. The most powerful are from large-diameter magnetic shafts: from cartridges 12A, 53A, 05A, 80A and the like, they press with their weight and are well magnetized to the iron surface, pressing the LED strips tightly:
As practice shows, it is better to replace all LEDs, since their PN junctions have already been subjected to extreme loads. Some (still working) LEDs often show signs of overheating, especially on the PCB on the back side of the LED strips. They burn due to the LED driver current being overestimated by the manufacturer, which is treated by modifying the power supply, namely by reducing the backlight current by selecting the current sensor rating, depending on the circuit used by the factory and the type of driver.
But more on that at the end of the article...
TVs often come in for repairs that have a demo mode for stores turned on, in which the backlight is turned up to full power, which also reduces the service life of the backlight. This mode can be disabled from the TV remote control through the menu.
Further. After repairing the LED bars, the image was also missing.
The power supply was inspected and the following was found:
Power supply VESTEL 17IPS11,
1) LED driver MP3394S is faulty, replaced.
2) N-channel MOSFET transistor FDD770N15A in the D-PAK package heats up, but still rings as good, replaced
Result: After replacing the above elements, the TV returned to working condition.
After such a repair, it is necessary to modify the power supply in order to reduce the backlight current of the TV.
How can you reduce the current using the example of a Vestel 17IPS11 board with an MP3394S driver?
Modification of the Vestel 17IPS11 power supply for the Toshiba 32w3453R TV:
Let's look at the datasheet for the MP3394S:
Let's look at the description of the 6-pin (ISET) driver:
“Tie a current-setting resistor from this pin to ground to program the current in each Led string. This pin voltage is regulated to 1.22 volt. The Led current is proportional to the current through the ISET resistor."
We translate: “Connect the output of this pin to ground through a resistor to program the current in each LED strip of LEDs. At this pin, the voltage is regulated to 1.22 volts. The LED backlight current is proportional to the current passing through this ISET resistor. "
In this case, on the 6th pin of MP3394s we see 2 SMD resistors marked 4701 (47*10=4.7 kOm). By selecting the value of these resistors, which are essentially a current sensor, the backlight current is regulated. By increasing the value of one of the resistors to 8-9 kOm, we reduce the backlight current. You can check the change in brightness (current) of the backlight visually or with an ammeter by inserting it into the open circuit of the LED strip power supply.
As practice shows, reducing the current to 250 mA does not affect image quality much, but the backlight will work longer and there will be no problems with LEDs burning out.
You can purchase LED strips for repairing the backlight of a Toshiba 32w3453r TV here:
| Set of two LED strips for Toshiba 32w3453r backlight repair |
For any questions, write to us in the comments or call us, phone number in the CONTACTS section
These tapes are a complete analogue of Vestel 32inch REV0.2 TIS-4A 94V. Unlike factory ones, the tapes are made on an aluminum substrate to dissipate the heat generated by the diode crystal, and have 3M tape along the entire length of the tape for mounting on the matrix.
PHOTO:
VIDEO ON DISASSEMBLYING THE MATRIX AND TEMPORARILY REPLACING FAULTY LEDS:
Write a comment:
- Use VKontakte
- Comment without registration
Social Comments
Toshiba 40L7363
artem658, 12/19/2017
Advantages: Toshiba 40L7363РК. The design is great, the picture is good, the sound is great, the menu is simple. 3D from hard drive via USB is excellent. Lots of functions. The price is excellent.
Disadvantages: detailed operating instructions are only on the official website. A lot has been written, but in certain cases it is not informative or does not correspond to the menu on the TV. According to the proposed instructions, it is impossible to set up a perfectly optimal image. Despite the fact that the TV has many functions, there are a lot of references that the TV may not work with certain equipment. There are no specifics. It seems that the TV has not been tested in different conditions and the developers themselves do not know the capabilities of their development. We can say that the instructions were written universally and at an accelerated pace. The developer received instructions with a minus. The remote control is generally satisfactory, with the exception of the menu editing buttons that are too small (the main disadvantage of the remote control).
According to the image. In certain cases, the shade of green overlaps other colors. How to adjust????
Not a complete instruction manual for 3D glasses, but extensive safety measures. The Toshiba FPT-AG03 glasses supplied in the kit are not on sale. According to the official dealer, the previous model FPT-AG02 is compatible.
Occasional, quite noticeable smell of plastic. (the presence or absence of odor is not mentioned in the instructions).
The TALK-7291 webcam recommended for this model is not available for sale. Analogues are not offered, as they have not been tested for compatibility with this TV model. (Scheduled to go on sale in February-March)
Comment: Connected through the Tricolor receiver. Connects to the Internet via a telephone line without problems. Provider Rostelecom via D-Link 2640U\RA router via cable. (speed according to the tariff 6500\700). (At the same time, a laptop is connected via WiFi). After a month, some functions froze: the menu did not open, 3D did not turn on, external input sources did not turn on. I reset the settings to factory settings (original upon purchase). During the process of installing the new settings, the TV connected to the Internet and offered to download the update. I installed everything without any problems. Everything worked. I only reflected what I encountered. If we knew the real technical capabilities of this model, then this TV could qualify for a higher rating. When choosing this brand of TV, neither retailers nor the official dealer in Moscow could provide professional advice. After 6 months it stopped showing. They suggested trying to reflash it. I downloaded the firmware from the site. There were no difficulties during installation. Earned it. The TV is damp.
TOSHIBA 32EL933RB WILL NOT TURN ON
Toshiba 32el933rb does not leave the duty room, the light is on!
Self-repair:
If you want to resolve the issue yourself
instructions and links to help:
1.Inexpensive programmer for 24 and 25 Series EEPROM Flash BIOS CH341A GOLD version
An inexpensive programmer, but it is quite sufficient for programming the BIOS flash memory of a computer, TV or any other supported flash memory:
socket for it
The SPI FLASH chip from Winbond must be replaced with a new one!
25 q 64 buy on Ali
25 q 32 buy on Ali
Toshiba 19el833r needs firmware for USB
# <- this is for comment / total file size must be less than 4KB
#set partition dynpart edb64M-nand:0x320000(KL),0xB20000(CONF),0x1600000(UBIA),0x1900000(UBIB),-(NA) saveenv
#mboot fatload usb 0:1 80400000 mboot.bin spi_wrc 0x80400000 0x00000000 0x00DFFFF
#mb60.bin fatload usb 0:1 80400000 mb60_en.bin crc32 0x80400000 0x01920014 0x81F00000 aes_test 0x80400000 0x82000000 0x01920010
## Must erase NAND before making factory.bin nand bad nand scrub nand bad
## Add fake bad block BEFORE making factory.bin ONLY!!! ## 0x10 = 16; 16x512x32=0.25M ## “rsv” command is available since mboot V105 #rsv bad KL 10 #rsv bad CONF 10 #rsv bad UBIA 10
#kernel #nand erase KL nand write.e 0x82000010 KL 0x320000
#nand erase UBIA ubi part UBIA ubi create RFS 0x600000 ubi create VEN 0xE00000
#ROOTFS ubi write 0x82320010 RFS 0x600000
#VENDOR ubi write 0x82920010 VEN 0xE00000
#CLEAN CRC32 mw 0x81000000 0xFFFFFFFF 0x04 spi_wrc 0x81000000 0xF1000 0x04
#CRC32 Create #ubifsmount VEN #ubifsload 0x82000000 /vendor/aurora.elf #crc32 0x82000000 0x000000 0x81F00000 #md 0x81F00000 #spi_wrc 0x81F00000 0xF1000 0x04
#conf, please mark below 4 line if you want to keep conf #nand erase CONF ubi part CONF ubi create CON 0xA00000 ubi write 0x83720010 CON 0x200000
#bootargs setenv MS_UBI ubi.mtd=1 ubi.mtd=2,512 root=ubi1:RFS rootfstype=ubifs rw setenv MS_MEM LX_MEM=0x3400000 EMAC_MEM=0 DRAM_LEN=0x8000000 setenv bootargs console=ttyS0,115200 $(MS_UBI) $(MS _MEM) $ (mtdparts) saveenv
#bootcmd setenv bootcmd ' nand read.e 81000000 KL; bootm 81000000; saveenv
#bootdelay setenv bootdelay 0 saveenv
printenv
## Read all 64M to RAM, ## then copy 64M from RAM to USB #rsv good #nand read.raw 80400000 0x0 0x41EF800 #fatwrite usb 0:1 80400000 factory.bin 0x41EF800
## KL=0x0, size=0x2E6800 ## CONF=0x339000, size=0xB37000 ## UBIA=0xEB2000, size=0x166E000 ## PARA=0x41DF000,size=0x4200 #reset
% <- this is end of file symbol
Here's another one:
# <- this is for comment / total file size must be less than 4KB
#set partition dynpart edb64M-nand:0x320000(KL),0xB20000(CONF),0x1600000(UBIA),0x1900000(UBIB),-(NA) saveenv
#mboot #fatload usb 0:1 80400000 mboot.bin #spi_wrc 0x80400000 0x00000000 0x00DFFFF
#mb62.bin fatload usb 0:1 80400000 mb62_en.bin aes_test 0x80400000 0x82000000 0x01920010
## Must erase NAND before making factory.bin #nand bad #nand scrub #nand bad
## Add fake bad block BEFORE making factory.bin ONLY!!! ## 0x10 = 16; 16x512x32=0.25M ## “rsv” command is available since mboot V105 #rsv bad KL A #rsv bad CONF 10 #rsv bad UBIA 10
#kernel nand erase KL nand write.e 0x82000010 KL 0x320000
nand erase UBIA ubi part UBIA ubi create RFS 0x600000 ubi create VEN 0xE00000
#ROOTFS ubi write 0x82320010 RFS 0x600000
#VENDOR ubi write 0x82920010 VEN 0xE00000
#CLEAN CRC32 mw 0x81000000 0xFFFFFFFF 0x04 spi_wrc 0x81000000 0xF1000 0x04
#CRC32 Create #ubifsmount VEN #ubifsload 0x82000000 /vendor/aurora.elf #crc32 0x82000000 0x000000 0x81F00000 #md 0x81F00000 #spi_wrc 0x81F00000 0xF1000 0x04
#conf, please mark below 4 line if you want to keep conf #nand erase CONF #ubi part CONF #ubi create CON 0xA00000 #ubi write 0x83720010 CON 0x200000
#bootargs setenv MS_UBI ubi.mtd=1 ubi.mtd=2,512 root=ubi1:RFS rootfstype=ubifs rw setenv MS_MEM LX_MEM=0x3400000 EMAC_MEM=0 DRAM_LEN=0x8000000 setenv bootargs console=ttyS0,115200 $(MS_UBI) $(MS _MEM) $ (mtdparts) saveenv
#bootcmd setenv bootcmd ' nand read.e 81000000 KL; bootm 81000000; saveenv
#bootdelay setenv bootdelay 0 saveenv
printenv
## Read all 64M to RAM, ## then copy 64M from RAM to USB #rsv good #nand read.raw 80400000 0x0 0x41CE800 #fatwrite usb 0:1 80400000 factory.bin 0x41CE800
## KL=0x0, size=0x30FC00 ## CONF=0x339000, size=0xB37000 ## UBIA=0xEB2000, size=0x166E000 ## PARA=0x41BE000, size=0x4200 #reset
% <- this is end of file symbol
HTTPS://VK.COM/COMP_REMONT_V_KIROVSKE
Who has already taken advantage
184227. Murmansk region. Kirovsky district. n.p. Koashwa
If you are in Kirovsk, Shlisserburg, Otradnoye or St. Petersburg, then repairs at your home (with this malfunction) are possible.
On-site repair: RUB 4,000. for any diagonal.
Stationary repair (in the workshop) =3200 rub.
The TV turns on, the screen says “DO NOT POWER OFF”, constant scanning is in progress.. The local keyboard buttons and the remote control do not respond.
