Friday, 21 August 2020

REPAIRING / SERVICING TV DNS 22AE7000

Technical description and composition of the DNS 22AE7000 TV, panel type and modules used. The composition of the modules.
DNS LED
Model: 22AE7000
Chassis / Version: T.SIS231.T65
Panel: CX215LEDM
LED driver (backlight): integrated into PSU
PWM LED driver: OB3350CP
MOSFET LED driver: AOD450
Power Supply (PSU): MP24S-CX
PWM Power: OB2273 (PWM SOT23-6)
MainBoard: T.SIS231.T65
IC MainBoard: 25Q64BSIG, NT5CB64M16FP, YD1517P, RT7237CH
Tuner: SI2T6Q
Specifications 22AE7000
DNS 22AE7000
General recommendations for TV LCD LED repair
Possible malfunctions
- DNS 22AE7000 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 MP24S-CX turns out to be faulty. Its output voltages should be measured and, in their absence, the serviceability of the power switches and rectifier diodes in the converters should be checked for possible breakdown.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually operate normally in an emergency short-circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and, less often, the current sensor in the source of the key.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements, which can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying the PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) OB2273 (PWM SOT23-6), in the absence of external damage and short circuit between the terminals, are checked by replacing them with a known good one.
- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and disappears immediately
Usually, in such cases, a malfunction is detected in the LED panel backlight nodes. The reason may be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To test the LED strips, in order to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in K / Z, then the LED is faulty and needs to be replaced.
- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.
Repair or diagnostics of the T.SIS231.T65 motherboard 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). When repairing an MB board, you need to check its components 25Q64BSIG, NT5CB64M16FP, YD1517P. Defective elements should be replaced. If chips with BGA soldering technology are used, the problem in its implementation is detected by local heating of the chip.
If you suspect a malfunction of the SI2T6Q 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 on the corresponding tuner pins.
Owners of the 22AE7000 TV are advised to contact only qualified specialists with the necessary experience for repair! Attempts to repair yourself without the appropriate knowledge and skills can lead to irreversible negative consequences!


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   DNS 22AE7000, Main: T.SIS231.T65, Panel: CX215LEDM


 The appearance of the MainBoard T.SIS231.T65 is shown in the figure below:
T.SIS231.T65
T.SIS231.T65 can be used in 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)).
External view of the power supply
Key features of the DNS 22AE7000:
Installed matrix (LED panel) CX215LEDM.
A converter combined with a power supply is used to power the backlight LEDs, and is controlled by the OB3350CP PWM controller. The keys of the AOD450 type are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the DNS 22AE7000 TV is carried out by the MP24S-CX power module, or its analogs using OB2273 microcircuits (PWM SOT23-6).
MainBoard - the main board (motherboard) is a T.SIS231.T65 module, using 25Q64BSIG, NT5CB64M16FP, YD1517P, RT7237CH and others.
The SI2T6Q tuner provides reception of television programs and tuning to channels.

 The CX215LEDM matrix and the MainBoard T.SIS231.T65 software provide viewing of broadcasts and films in high quality HD at a resolution of 1920x1080 pixels in graphics resolution at 1080p (Full HD). The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and formation of a digital signal occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, DivX, MKV, JPEG.
Speaker power of 6 W (2x3 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
An external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, SCART, VGA, HDMI, USB. A headphone output is provided. To connect a computer or laptop to this TV model, use the VGA (D-Sub 15) connector on the TV case, this interface supports resolutions: 1920x1080. The digital tuner is capable of receiving television channels in the DVB-T, DVB-C, DVB-T2 standards.
The TV uses the MP24S-CX power supply.
Dimensions: With stand 720x520x220 mm, Without stand 720x460x80 mm.
TV weight: 2.93 kg.
Attention! The CX215LEDM panel of the DNS 22AE7000 LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.