17IPS19-5 LED TV does not start (Flashing Standby)

[MrSnow]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

Steady

[MrSnow]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

Circuit only D506
Anode: 24V, Cathode 23,6V

D207, D206: Cathode 24V, Anode -3,0V
D318-320: Cathode 12,2V, Anode -0,5V

[dick_barton]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

OK. I read that the 24V supply was dropping and was trying to trace why, but you say it is steady.

So it is a backlight driver problem and you have verified the leds as working.

If you can say what the voltages are on the diodes above may be helpful.

[dick_barton]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

Circuit only D506
Anode: 24V, Cathode 23,6V

Can you check what voltage is on Pin 15 of PL200 in standby and out of standby. This is the backlight On/Off control signal provided by the main board.

[ReeceyBurger123]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

Right so you checked the mosfet as I suggested ?

[MrSnow]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

Right so you checked the mosfet as I suggested ?

I don´t know how I have to check this.

OK. I read that the 24V supply was dropping and was trying to trace why, but you say it is steady.

Only if the mainboard is not connected the 24v drops to 0 V.

So it is a backlight driver problem and you have verified the leds as working.

Backlight driver problem = MP3394?
The LEDs work with a laboratory power supply

If you can say what the voltages are on the diodes above may be helpful.

I had written. Is this sufficient?

THANK YOU VERY MUCH!



Thank you

[MrSnow]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

Can you check what voltage is on Pin 15 of PL200 in standby and out of standby. This is the backlight On/Off control signal provided by the main board.

Pin 15 0V. There is only standby (or no standby), the TV dont responds if i try to switch on or off.
I can only turn on the mains plug. Then he flashes, reacts to no buttons. Switching off is also possible only via the mains plug.

[dick_barton]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

I think that Pin15 of PL200 should be 3V>> when the set is turned on out of standby to turn on the backlights.
You could check the voltage on R503 connected to the led driver chip.

[MrSnow]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

Hmmm...

Cant find R503. DOH
The Service Manual is a little bit different.

[budm]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

I just read through the thread.
1) There is no PFC Voltage booster so the DCV on the main cap should be around 330VDC.
2) The 'ST_BY' is the same as 'PS-ON' but in this case it is active LOW, LOW (<1V = ON).
So what DCV do you have at 'ST_BY' pin when TV is OFF, and when power switch is activated?
Looking at the schematic, when TV is OFF Q310 will be ON which in turn will keep Q309, OPTO IC302 in OFF STATE so there will be no VCC output from switched Q306 to feed the 24V SMPS.
When 'ST_BY' goes low, Q310 will be OFF, that will allow Q309 to turn on, so the LED inside OPTO IC302 is turned ON which will turn on Photo-transistorinside the OPTO.
For the switched Transistor Q306 that supplies the VCC to be on, Q308 must be on when VCC_MAIN is present and Q305 Over Voltage protection transistor Q305 is OFF so then the Q306 will be on, it is PNP so the BASE Voltage have to be lower then the Emitter Voltage, that is done through Q308, IC302.
So the 24vdc POWER SUPPLY puts out 24V and then drops down, right? so we need to know the status of ST_BY, and the VCC.

[MrSnow]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

I just read through the thread.
1) There is no PFC Voltage booster so the DCV on the main cap should be around 330VDC.
2) The 'ST_BY' is the same as 'PS-ON' but in this case it is active LOW, LOW (<1V = ON).
So what DCV do you have at 'ST_BY' pin when TV is OFF, and when power switch is activated?
Looking at the schematic, when TV is OFF Q310 will be ON which in turn will keep Q309, OPTO IC302 in OFF STATE so there will be no VCC output from switched Q306 to feed the 24V SMPS.
When 'ST_BY' goes low, Q310 will be OFF, that will allow Q309 to turn on, so the LED inside OPTO IC302 is turned ON which will turn on Photo-transistorinside the OPTO.
For the switched Transistor Q306 that supplies the VCC to be on, Q308 must be on when VCC_MAIN is present and Q305 Over Voltage protection transistor Q305 is OFF so then the Q306 will be on, it is PNP so the BASE Voltage have to be lower then the Emitter Voltage, that is done through Q308, IC302.
So the 24vdc POWER SUPPLY puts out 24V and then drops down, right? so we need to know the status of ST_BY, and the VCC.

Hi! Thank you for reading and for your answer.
I can´t turn the TV on or off. As soon as I turn on the powerswitch, it starts flashing.
---
I forgot:
In the state after plugging in the mains switch, pin 17 is supplied with 3.3 V.

[budm]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

It needs to go LOW when TV is turned on.

[MrSnow]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

Thank you, I do not know how to continue. Does anyone else have an idea?

[dick_barton]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

You can try this:-
Disconnect the main board.
Connect a 1K resistor from 5VSTBY to BL_ON/OFF
Are all your voltages up 5V, 12V, and 24V steady
Do the backlights come on?

[MrSnow]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

Hello again.
Sorry for the late answer. I bought a new power supply.
The Problem still exists.
So the mainboard will have a problem.
Can I still do anything here? I can´t install a new Software via usb.

[ReeceyBurger123]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

What software are you using please upload it so I can check. Your doing something wrong or there is another hidden fault on the board.

[MrSnow]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

The usb drive wont identified. I have tried this one: http://www.vesteldriver.com/TV_MB82_CORE_UPDATE.html

The mainboard has a thermal problem.
If i use a hair dryer, then flashs the usb drive and the backlight.

What must be considered when buying a used mainboard?

[vinceroger69]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

what is the lcd panel number used in this tv its usually on a white sticker

[ReeceyBurger123]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

Hmm did you put it on the usb correctly ? Even if its the wrong software it would flash the Led very fast then stop. So did you unzip it properly as Ive shown in vids.

[viorel.m]

Re: 17IPS19-5 LED TV does not start (Flashing Standby)

What is the voltage between the 2 legs of C116. It should be around 380V. Place your meter probes on each leg of the capacitor.

Hello.
I'm writting here because I have the same simptoms in my 32" Telefunken.
Model: D32H127N2.
Inside is a Vestel 17IPS18-5 V.1 with the MB 17MB82-1a.
On the metallic case is a label with Model:VES315WNDB-01.
I wrote at this step because between the pins of C116 there are only 210V.
The diodes(12/24V) are ok, they are not shorted, but at both ends of diode D506 are 24V.
On the PL501, on the black wire pin ,23V and on the red 2V.
On the PL200 connector toate MB the voltages are like this:
0V, 3.3V, 23.8V, 12.2V, 5.1V, 5.1V 3.3V, 0V, 0V, 0V.
But still there ist no Backlight and the standby LED flashes continously.
Please help.
Thank You.