Saturday 21 December 2019

REPAIRING / SERVICING TV SAMSUNG LA32C450

Technical description and composition of the SAMSUNG LA32C450 TV, panel type and applicable modules. The composition of the modules.
SAMSUNG
Model: LA32C450
Chassis / Version: N88A
Panel: LFT320AP08
Power Supply (PSU): BN44-00338B
PWM Power: ICE3BR1765J (Standby), FAN7530 (PFC), FSFR1700US
MOSFET Power: 13N60N, MDS1653
MainBoard: BN41-01331B BN94-03988Q
IC MainBoard: SEMS16 1028B-LF, WT61P802, A7MG509D, NTP-7300S
Tuner: BN40-00180A
Appearance
SAMSUNG LA32C450
General repair guidelines for TV LCD
Repair of the SAMSUNG LA32C450E1D TV should begin with a careful external inspection and diagnosis of the malfunction. In this case, it is advisable to carefully examine both internal and external components. Often, based on certain external signs, it is possible to draw some conclusions about the reasons for the failure of certain circuit elements even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. In some cases, faulty elements are visible to the naked eye, for example, charred resistors or swollen metal-ceramic capacitors, or electrolytic in rectifier filters. Ring cracks formed in the soldering of the terminals of transformers or heating elements of the circuit are also frequent sources of many malfunctions with a variety of external manifestations.
If the SAMSUNG LA32C450E1D does not turn on, no control lights on the front panel are on or blinking, therefore, there is a very high probability of a malfunction of the PSLF121401A power module, in some cases BN44-0338A. When diagnosing and repairing the PSLF121401A or BN44-0338A power supply, first of all, it is necessary to check the fuse, and if it breaks, the power switch and rectifier bridge diodes should be checked for avalanche (thermal) breakdown.
In most cases, a breakdown of the N-Fet converter key does not occur for no reason and you should look for other faulty circuit elements that could provoke a defect. This can be dried electrolytic capacitors in the primary circuit, and faulty damper elements, as well as dangling resistors or punched semiconductor elements in the stabilization circuits. Possible defective PWM FAN7530 chip from the manufacturer.
These models use BN44-0338A or BN44-0338V power modules using the Active Power Factor Corrector (CMC), in the international abbreviation PFC (Power Factor Correction). Troubleshooting in such cases can be somewhat more complicated and require additional knowledge and skills. Features of the diagnosis and repair of such modules will be discussed in a separate topic.
If the SAMSUNG LA32C450E1D TV does not have an image, but there is sound, the malfunction should be sought in the power converter of the backlight (inverter). It is also necessary to check the serviceability of the electrolytic capacitors of the filter of the secondary rectifiers of the BP (power supply) for an overstated ESR.
Repair of the SSI320_4UH01 inverter can often be somewhat complicated by the use of special protection circuits, which are designed to disconnect it in emergency cases for fire safety when the lamps are depressurized, or short circuits or breaks in high-voltage circuits and connections. Sometimes it becomes necessary for diagnostic purposes to block the protection circuits in order to be able to make the necessary measurements at the control points of the circuit.
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.

Diagnostics and repair of motherboards BN94-03988Q, BN41-01331B or BN40-00180A, which can be installed in the models under consideration, is carried out by checking the performance of power stabilizers or updating the software (software). In some cases, it is necessary to check or replace (if necessary) the elements of the MB board (SSB) - SETD10 A0A21 H A LAA02, K4T1G1640F-BCF8, ATMLH034 02G, SIL9287BCNU, STA3698WS.
For owners of the LA32C450E1D TV, we recommend that you contact qualified personnel with experience to repair! Self-repair attempts without the appropriate knowledge and skills can lead to serious negative consequences!


The appearance of the MainBoard BN41-01331B is shown in the figure below:
BN41-01331B
BN41-01331B can be used in TVs:
SAMSUNG LA32C450 (Panel LFT320AP08), SAMSUNG LA32C450E1D (Panel LTF320AP08 A10), SAMSUNG LE26C450E1WXRU (Panel LTF260AP04), SAMSUNG LE32C530F1 LE32C53051F5W5405L Panel, LTF320HMF150, SAML5505F150, Panel LTF320HMF150
PSU Advanced
The power module BN44-00338B is made using the Power Factor Correction (PFC) scheme to eliminate multiple AC harmonics introduced by the device into the mains. The PFC assembly is a Step-Up Converter based on a FAN7530 PWM controller that evenly distributes high-frequency impulses of the charging current of the electrolytic capacitor of the rectifier filter of the mains voltage over a period of 50 Hz. The current of its charge in this case will already be determined not by its reactance (usually 10-30 ohms for the network frequency), but by the elements of the converter. As a result, a change in the amplitude of the pulses (envelope) of the consumed current of the converter will repeat the shape and phase of the input sinusoidal voltage. The availability of the increased voltage (about + 380V) in the operating mode on the capacitor of the line filter indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the SAMSUNG LA32C450 device:
Installed matrix (LCD-panel) LFT320AP08.
The necessary supply voltages for all nodes of the SAMSUNG LA32C450 television are generated by the BN44-00338B power supply module or its analogs using ICE3BR1765J (Standby), FAN7530 (PFC), FSFR1700US and power switches type 13N60N, MDS1653 microchips.
MainBoard - the main board (motherboard) is a BN41-01331B module, using chips SEMS16 1028B-LF, WT61P802, A7MG509D, NTP-7300S and others.
The tuner BN40-00180A provides the reception of television programs and tuning to channels.
Information from an alternative source:
SAMSUNG LA32C450E1D Chassis N88A
Panel Type (Matrix): LTF320AP08
Motherboard: BN41-01331B, SETD10 A0A21 H A LAA02, K4T1G1640F-BCF8 x2, ATMLH034 02G, SIL9287BCNU, SETD-70, STA3698WS, DRV604, 25X40BVSIG, Tuner: TDAG4-K01A BN40-001
T-con: 320AP08S4LV0.3, LAXC021T0B-Q1 M2B99800105, MAXIM994E, 24C64WP, 402WP, W866, 10231PHB x2, TPS65171, DA38AL, 17121E TG031
Invertor: SSI320_4UH01, SSI091ASN
PSU: PSLF121401A, FAN7530