26Hfl3331D Philips

[marsi123]

Ciao a tutti, sono nuovo del forum e complimenti.

Ho il tv in questione che ha qualche lampada esaurita, dopo pochi secondi va via la retroilluminazione.

Vorrei baipassare la protezione delle lampade per vedere quale lampada da meno luce per poi sostituirla, sapreste dirmi come fare.

Grazie a tutti in anticipo.

[Luigi Di Donato]

Ciao e benvenuto.

Dacci la sigla del pilota sulla scheda inverter, cioe' l'integrato che pilota i mosfet.

[marsi123]

ok appena rientro lo faccio, grazie

[marsi123]

Salve la scheda di alimentazione con inverter incorporato è : pwtv9gc1lpr2

La sigla del pilota è - UBA 2071AT

grazie

Modificato: 3 settembre 2014 da marsi123

[marsi123]

Allego questa immagine con la sigla per ogni piedino dell'integrato.

Immagino da come ho letto in giro che bisogna metere a massa uno di questi piedini.

[marsi123]

Aggiungo una descrizione di ogni piedino dell' integrato.

-----------------------------------

Symbol Pin Description Function

IFB 1

current feedback input. Input signal for the lamp current control loop. Should be connected to a

voltage proportional to the lamp current.

CIFB 2

current regulation

capacitor.

A capacitor must be connected between this pin and the signal ground. It

sets the time constant of the lamp current control loop.

VFB 3

voltage feedback input Input signal for the voltage control loop. Should be connected to a voltage

proportional to the transformer output voltage.

CVFB 4

voltage regulation

capacitor

A capacitor must be connected between this pin and the signal ground. It

sets the time constant of the voltage control loop.

CSWP 5

frequency sweep

capacitor

A capacitor must be connected between this pin and the signal ground. It

sets the time in which the HF frequency is swept up from regulation level to

the maximum frequency and back during PWM dimming.

CT 6

fault timing capacitor A capacitor must be connected between this pin and the signal ground. It

sets the time that a fault condition is allowed before the IC shuts down itself.

CF 7

HF-oscillator timing

capacitor

A capacitor must be connected between this pin and the signal ground. It

sets the minimum switching frequency of the half bridge.

IREF 8

reference current output A 33 kW resistor must be connected between this pin and the signal ground.

The IC uses it to make accurate internal currents.

CPWM 9

PWM timing capacitor If a capacitor is connected between this pin and the signal ground, it sets the

frequency of the PWM oscillator.

If this pin is connected to signal ground the internal PWM oscillator is

disabled.

SGND 10

signal ground

COMM 11

master / slave

communication

Via this pin the IC can communicate with a dedicated slave device.

NONFAULT 12

status signal

input/output

The IC signals a fault condition to external circuits by pulling this pin low. Also

external circuits can signal a fault condition to the IC by pulling this pin low.

PWMD 13

digital PWM dimming

input/output

Digital output of internally generated PWM signal if a capacitor is connected

to the CPWM pin.

Digital input of PWM signal if the CPWM pin is connected to signal ground.

Remark: The signal on the PWMD pin is active low, so low voltage on the

PWMD pin means lamps are on.

PWMA 14

analog PWM dimming

input

The duty cycle of the internally generated PWM signal is proportional to the

voltage on this pin.

EN 15

chip enable input A low voltage on this pin will reset and shut down the IC. This pin is also used

to select between DC blocking capacitor charging mode and normal

operation.

VDD 16

supply input A buffer capacitor must be connected between this pin and power ground.

PGND 17

power ground return for the low-side driver.

GL 18

low-side driver output Gate connection of the low-side power switch.

n.c. 19

not connected HV spacer pin.

n.c. 20

not connected HV spacer pin.

n.c. 21

not connected HV spacer pin.

SH 22

high-side source

connection

Return for high side gate driver. Must be connected to the source of the

high-side half bridge power switch.

FS 23

floating supply A buffer capacitor must be connected between this pin and the SH pin. This

capacitor is charged when the low-side power switch is on and supplies the

high-side driver when the high-side power switch is on.

GH 24

high-side driver output Gate connection of the high-side half bridge power switch.

Modificato: 8 settembre 2014 da marsi123

[marsi123]

Salve, visto che mia figlia reclama il tv volevo fare un ultimo tentativo prima di buttarlo, secondo voi se sostituisco

l'integrato UBA 2071AT potrei risolvere?

Grazie

Modificato: 2 ottobre 2014 da marsi123