Technical description and composition of the TOSHIBA 32AV704R TV, type of panel and applicable modules. The composition of the modules.Toshiba
Model: 32AV704R
Chassis / Version: MST3740EU-T MAIN BD manufactured by UNIHAN
Panel: V315B5-L12 Rev01 75018968
Inverter (backlight): T78I029.26 CPCsE5 ETL-XPC-204T I315B5-4UE 75021314
PWM Inverter: BD9215FV
MOSFET Inverter: AO4164
Power Supply (PSU): FSP132-3F01
PWM Power: A6069H (7), SSC9512S (18), SSC9502 (18), 1607B (PFC)
MainBoard: MST3740EU-T 75020414 69EB3IM10C09P
IC MainBoard: MST9B884JL-LF-3, MX 25L1605DM2I, W9412G6IH-4
Tuner: TT2124
Control: CT-90326
Specifications 32AV704
TOSHIBA 32AV704R
General recommendations for repairing TV LCD
It is advisable to start any repair and diagnostics of the TOSHIBA 32AV704R TV with a careful external examination of internal and external elements, including case parts, a display, buttons and cables. Many visible signs make it possible to determine the future direction of troubleshooting and localization of the defect. In some cases, faulty elements can be seen with the naked eye, for example, charred resistors or swollen metal-ceramic capacitors, or electrolytic in rectifier filters. Ring cracks formed in the soldered terminals of transformers or heating elements of the circuit are also frequent sources of many malfunctions with a variety of external manifestations.
In cases where the TOSHIBA 32AV704R TV does not turn on, does not respond to the remote control and buttons, no indicators on the front panel light up or blink and there are no sounds and no signs of operability when turning on, the power supply module FSP132-3F01 is most likely faulty or, which happens much less often - there is no power to the processor on the motherboard. When diagnosing and repairing the FSP132-3F01 power supply unit, it is first necessary to check the fuse, and if it breaks, the power switch and rectifier bridge diodes should be checked for avalanche (thermal) breakdown.
As a rule, the keys of flyback converters, which use the N-Fet field effect transistor on a separate radiator, or integrated with the SSC9502 (18) A6069H (8) PWM controller in a single chip, are quite reliable and rarely fail for no reason. The reasons for the breakdown of the key should be sought by checking other components of the circuit - electrolytic capacitors, resistors and semiconductor elements of the primary circuit. The PWM chip is verified by replacing it with a known good one.
If the power module uses an active KKM circuit (power factor control), troubleshooting is somewhat more complicated.
If, when you turn on the TV, the image appears and immediately disappears, or is initially absent when you turn on, but there is sound and other functions work, there is a high probability of a malfunction of the inverter (power converter for the backlight). In such cases, the lamps, the inverter and the common power module are subject to verification, in which the electrolytic capacitors of the rectifier filter supplying the inverter should be checked.
In most cases, the diagnosis and repair of the T78I029.26 CPCsE5 ETL-XPC-204T I315B5-4UE 75021314 inverter is difficult due to the organization of protection, which turns it off in emergency cases to avoid fires during short circuits or open circuits in high voltage circuits and during depressurization of lamps. Often, repairmen block the protection circuits in order to make the necessary measurements at the control points of the inverter to identify the causes of the defect.
It should be remembered that in such cases there is a risk of failure of the power elements of the inverter and to take special care. After carrying out repairs, the protection circuit must be restored for further safe operation of the TV.
If the motherboard MST3740EU-T-75020414 69EB3IM10C09P is faulty, first of all it is necessary to check all the linear power regulators of its chips and, if necessary, update the software. Sometimes you can check the health of MB only by replacement.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair only to professionals with sufficient experience in the field of electronic equipment repair.
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> Toshiba 32AV703R. Ver. 2.00 MST3740EU
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> TOSHIBA Power Supply FSP132-3F01
Service Manual 51 pages on models 19AV703R, 22AV703R, 26AV703R, 32AV703R, 32LV703R, 37LV703R, 40LV703R, 19AV704R, 22AV704R, 26AV704R, 32AV704R, 32LV704R, 37LV704R, 40LV704R
The appearance of the MainBoard MST3740EU-T is shown in the figure below:MST3740EU-T
MST3740EU-T can be used in TVs:
TOSHIBA 26AV703R (Panel V260B3-L04 RevC1), TOSHIBA 32AV703R C (Panel V315B5-L12 75018968), TOSHIBA 32AV703R K (Panel LTA320AP08 75016146 ), TOSHIBA 32AV704R (Panel V315B5-L12 Rev01 75018968), TOSHIBA 32LV703R A (Panel T315HW04 V.4 (12v) 75018019), TOSHIBA 32LV703R K (Panel LTA320HA04 T01 75016399 (12v)), TOSHIBA 40LV703R C (Panel V400H1-L10 REV C1 75018974), TOSHIBA 40LV703R K (Panel LTA400HM02 T03).
PSU Advanced
The 32AV704R model uses the FSP132-3F01 power supply unit using the PFC (Power Factor Correction) node - an active filter of the highest harmonics of the current consumption. In fact, it is a step-up converter based on the 1607B PWM controller, which eliminates the charge current of the electrolytic capacitor of the rectifier filter directly from the network through open diodes when its charging current is determined by its reactance.
As a result of the operation of the converter, the envelope of the high-frequency pulses of the input current of the converter will repeat the shape and phase of the input voltage. The health of the PFC node can be indirectly judged by the presence of an increased constant voltage (about + 380V) on the capacitor of the rectifier network in operating mode.
The appearance of the power supply
Main features of the TOSHIBA 32AV704R device:
Installed matrix (LCD panel) V315B5-L12 Rev01 75018968.
To power the backlight, an inverter T78I029.26 is used, it is controlled by the BD9215FV PWM controller. As power elements of the inverter, keys of the AO4164 type are used.
The necessary supply voltages for all nodes of the TOSHIBA 32AV704R TV are generated by the FSP132-3F01 power module, or its analogs using A6069H (7), SSC9512S (18), SSC9502 (18), 1607B (PFC) microcircuits.
MainBoard - the main board (motherboard) is an MST3740EU-T module, using microchips MST9B884JL-LF-3, MX 25L1605DM2I, W9412G6IH-4 and others.
The TT2124 tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V315B5-L12
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 697.685x392.256 mm
Surface: Antiglare (Haze 11%), Hard coating (3H)
Brightness: 450 cd / m²
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 8.5 (G to G)
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V