Toshiba 40L1333DB not turning on

[smiddy1980]

Hello I have a Toshiba 40L1333db that wont power on, I am getting power going to the mainboard between 16v and 23v, when I unplug the main board it sits at a steady 23.2v is that an issue with the PSU or the Main board?

Thanks guys

[dskall]

Re: Toshiba 40L1333DB not turning on

Need good clear straight on pictures of back of tv with cover off and each board.

[smiddy1980]

Re: Toshiba 40L1333DB not turning on

Sorry I meant to unload these

[smiddy1980]

Re: Toshiba 40L1333DB not turning on

Do you think the main board can cause the power to voltage to go up and down like this or it is the PSU?

[maxvalutech]

Re: Toshiba 40L1333DB not turning on

Is there a red standby light working if so there normally is a 5v line on PSU connector a ps-on or on to main board which if main OK then switches all other voltages on but also a backlight switch on etc. Lack of info gives a lack of response.

[dick_barton]

Re: Toshiba 40L1333DB not turning on

+1
It would help if you can give the dc voltages on CN4

[smiddy1980]

Re: Toshiba 40L1333DB not turning on

Sorry for the lack of info guys, I'm not 100% sure of the layout of the pins but looking at CN4 on the board pin one being bottom left here is what I get the only voltage I get is pin 9 goes from 6 to 11v ping 12 13.2v that's with the main board disconnected

[smiddy1980]

Re: Toshiba 40L1333DB not turning on

sorry pin 12 is 23.2v

[maxvalutech]

Re: Toshiba 40L1333DB not turning on

This is a LED set with the dreaded Vestel PSU. In my country we have all Chinese manufactured gear generally and no scarrt connectors so my comments are general. Your standby red light is going out at switch on and the power is coming on to a degree. Voltage fluctuations can be used as signals to turn on other circuits. At top of PSU what voltage is going from white connector to leds? For the other connector are pins identified on the board/s on top or underneath? Do you get sound? Does the set turn off OK as usual with remote or set button ? Any sign of screen lighting up at all even a flicker at switch on ? From answers to these and other questions the gurus can be confident in a diagnosis to assist in a fix. Most people look to board replacement as the solution but power supplies can sometimes be easily fixed. LED string problems are another matter.

[maxvalutech]

Re: Toshiba 40L1333DB not turning on

Only just noted dick_barton has shown the pinouts. So your voltage readings raise question is you dmm reading correctly as a 5v movement would be likely at switch on for pin 9 but usually from near nil to 5. Also 23v instead of expected 12v is strange.
No voltage at backlight on so you need to isolate PSU from main and force it on to check what it does then force backlight on to see if LEDs respond. Dick will know which connections to make on this particular connector.

[zomi]

Re: Toshiba 40L1333DB not turning on

What is the red light doing ?

flash green - red continoulsy..
goes green .. and nothign on scree
just stays red ?

[smiddy1980]

Re: Toshiba 40L1333DB not turning on

Zomi, The light is red then green then off, its like the sets starts then shuts off and continues n this fashion

Maxvalutech I will check my meter to make sure I am on the correct setting, pretty sure I am

[smiddy1980]

Re: Toshiba 40L1333DB not turning on

yeah my settings are ok, I can hear the board making a small clicking noise, like a switch going on /off very faint, with everything disconnected I'm am getting these voltages so I think it is the PSU that's at fault

[maxvalutech]

Re: Toshiba 40L1333DB not turning on

I agree and the Vestel PSU hasn't many admirers on this forum as far as I can see. The relay clicking is normal as it switches. At switch on the 5v signal goes to main which reacts by voltage change back to PSU which then starts all other voltage outputs including sound and backlights the latter also usually controlled via main. Look to troubleshoot PSU by searching in forums or just replace with known good one if economical. Good luck with it.