Technical description and composition of the SAMSUNG LA32A330 TV, panel type and applicable modules. The composition of the modules.
SAMSUNG
Model: LA32A330 LA32A330J1N
Chassis / Version: N61A
Panel: LTF320AP01
Lamp backlight: 12 Lamp CCFL
Inverter (backlight): integrated into PSU
PWM Inverter: OZ9970GN
Power Supply (PSU): BN44-00235B
MOSFET Power: 2SKK3561
MainBoard: BN41-00984A
IC MainBoard: SEMS01, MX25L1605A, 24C256
Tuner: BN40-00098A
Appearance
SAMSUNG LA32A330
General repair guidelines for TV LCD
Like any other TV, it is advisable to start repairing SAMSUNG LA32A330 or LA32A330J1N with a careful examination of the external and internal elements. Sometimes, for some visible changes, you can determine the further direction of the defect search and localization of the malfunction before the start of taking the oscillograms and making the necessary measurements at the control points. Ring cracks in the soldering of the leads of the elements, deformed electrolytic capacitors, charred resistors - all this for the repairman can be a hint in assumptions about the causes and consequences of the malfunction.
If the power supply module malfunctions, external manifestations may be different, for example, the TV does not turn on at all and there is no indication of the control lights on the front panel. When diagnosing and repairing the power supply, first of all, it is necessary to check the fuse and, if it is broken, it is necessary to identify the cause. Often in such cases, an avalanche (thermal) breakdown is detected in the power semiconductor elements of the module - rectifier diodes or power key.
It should be borne in mind that in the practice of repair it is extremely rare that key transistors of the N-FET type fail for no reason that should be sought by checking other components, for example, a breakdown of the key can provoke faulty elements of the damper circuits, or dried electrolytic capacitors or dangling resistors of the primary power supply circuit, involved in the stabilization process. In this case, all semiconductor elements of the strapping of the PWM controller chip are subject to verification, which it is desirable to verify by replacement.
It is somewhat more difficult to look for a malfunction in the converter of the power module with an active KKM (power factor corrector).
In cases where the SAMSUNG LA32A330 or LA32A330J1N TV has lost its image, and the sound is there and all other functions are functional, there is a possibility of an inverter (converter for powering the backlight) malfunction. When you turn on the TV, the image may appear briefly and immediately disappear. It should be borne in mind that with such manifestations, the lamps themselves also fail, the malfunction of which can be detected by replacement, by connecting to the connectors for diagnostics that are known to be serviceable and suitable in power.
Diagnostics of the inverter can be difficult due to the operation of the protection, which is organized by the designers to prevent negative consequences or fires in emergency cases, for example, during short circuits or breaks in the lamp power supply circuit, as well as their possible depressurization. To make the necessary measurements at control points or to take the necessary waveforms, repairmen have to block the protection circuits in order to be able to diagnose.
In such cases, the risk of failure of the power elements of the inverter is most likely, and special care is required during work, and after their completion, it is necessary to restore the protection circuit for further safe operation of the TV by the owner in normal mode.
Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements SEMS01, MX25L1605A, 24C256.
I recommend the owners of the LA32A330 LA32A330J1N TV for repair only to qualified specialists with experience! Self-repair attempts without the appropriate knowledge and skills can lead to serious negative consequences!
SCHEMATIC DIAGRAM / SERVICE MANUAL ----------> Samsung LA32A330J1X Chassis GJE32ASA-N61A.
The appearance of the MainBoard BN41-00984A is shown in the figure below:
BN41-00984A
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the BN44-00191B module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the FAN7530 PWM controller. The reactance of an electrolytic capacitor of a line filter at a frequency of 50-60 Hz is usually not more than 20-30 ohms and its charge directly from the network through open diodes could reach tens of amperes per pulse if no filtering were applied.
As a result of the PFC conversion, an increased voltage on the capacitor (about 380V) cannot directly open the rectifier diodes, on the anode of which the voltage will always be slightly less (about 300V) and then its charging current will always be limited by the elements of the PWM controller. As a result, the envelope of the high-frequency pulses of the consumed current will repeat the shape and phase of the input sinusoidal voltage. The presence of an increased voltage (+ 380V) on the mains capacitor indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the SAMSUNG LA32A330 device:
Installed matrix (LCD panel) LTF320AP01.
To power the backlight, a converter is used, combined with a power supply, controlled by the OZ9970GN PWM controller.
The formation of the necessary supply voltages for all nodes of the SAMSUNG LA32A330 TV is carried out by the BN44-00235B
power module, or its analogs using power switches of the 2SKK3561 type.
MainBoard - the main board (motherboard) is a module BN41-00984A, using microchips SEMS01, MX25L1605A, 24C256 and others.
The tuner BN40-00098A provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTF320AP01
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: PVA, Normally Black, Transmissive
Active Area: 697.68x392.26 mm
Surface: Antiglare (Haze 14%), Hard coating (3H)
Brightness: 450 cd / m²
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 8 (G to G)
Frequency: 60Hz
Lamp Type: 12 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
