Repareer je spullen Gemeenschap Winkel

Handleidingen en ondersteuning voor allerlei TV's.

9032 Vragen Bekijk alle

Opties

Toshiba 40L1533DB TV Backlight keeps shutting off.

Block Image

Block Image

Block Image

Block Image

I recently purchased a second hand Toshiba 40L1533DB TV, when powered on initially all is fine, however the TV’s backlight turns off after some time. Interestingly, depending on the backlight mode, the time taken for the TV to turn of varies. On Low mode the TV’s backlight stays on for about an hour, but on medium or high this time is less.

After turning the TV back on immediately after the failure, the backlight goes out again much sooner.

I am wondering what area of the TV is at fault, perhaps the Power Supply board or the LED backlights themselves. Obviously if the LED strips were at fault themselves it would be a much more challenging repair.

Beantwoord! Bekijk het antwoord Dit probleem heb ik ook

Is dit een goede vraag?

Ja Nee
Score 1
2 opmerkingen

@samhodgson does the power board look like it got/gets hot on the isolated transformer side? May just be the picture but it sure looks like it....Take a picture of the underside as well since that is where the boost converter and switching mosfet are located. Let's see....

door

Hi there I have 55l7453D toshiba when turn on tv get sound no pic when bang on tv in places the backlights come back on and it works fine for hours but soon as I turn it of again on standby I have to do it again knock tv and backlights come back on again can anyway tell me what's happening and how to fix it

door

Voeg een opmerking toe

2 Antwoorden

Filteren op:
Meest nuttige Nieuwste Oudste
Gekozen oplossing

Opties

@samhodgson Toshiba is another one of the black helicopter companies that think everybody wants to steal their products. There will be no support from them as well as only scarce information i.e. service manuals, schematics etc. They are guided by paranoia and DO NOT SUPPORT independent repair. Anyhow…

This sound like it could be an issue with the “inverter” circuitry on your power board or the LED’s of the backlight strip. Measure the voltage on the LED connector of your boards while the backlight is on and again once it should turn off. IF the voltage does not get supplied you know the issue is not the backlight array. If the voltages stay essential the same, it is the backlight array. Another thing to check would be to see if the backlight has failed or if the main board turned it off. Once the screen is dark (you still have sound) shine a flashlight at an angle against the screen. If your can still make out shapes, silhouettes etc. you know it is the backlight if not then it could be the main board turning it off due to some overheating failure. My order of suspects are backlight array, power board, main board, others :-)Post some good pictures of your boards with your question so that we can see what you see. Voeg afbeeldingen toe aan een bestaande vraag

Update (02/23/2020)

This might just help you out to measure your power board

Block Image

Block Image

Was dit antwoord nuttig?

Ja Nee
Score 1

8 opmerkingen:

Thank you for your reply, unfortunately I do not have a multimeter to test it with. When the backlight goes out an image is still on the screen (this can be seen with a torch). I am able to buy a replacement power supply board for £20 so may do this. Still puzzling why the TV would stay on longer on a Low backlight setting (possibly suggests to me the strips themselves are bad). I have attached some pictures. In terms of the hot looking area of the board the used parts I have come across seem to have this too, maybe a design flaw? This could potentially explain the issue.

door

On further research, some of the power supply parts (which I imagine are removed from smashed units) do not have such a severe tinge to the board. Perhaps it is the power supply after all!

door

@samhodgson it does look like the power supply. I just hate for you to spend your hard earned money on something that we could test first but I understand about not having a multimeter. Get the board form a place where you could possibly return it if needed.

door

I have now ordered a replacement power supply board for £19. It all seems to make sense about why the TV would turn off more quickly after a previous backlight failure (because this board was too hot). Thank you so much for your help, £20 will hopefully fix the issue and more importantly stop this going to landfill. It’s crazy to think the amount of TV’s that are discarded because of issues like this.

door

@samhodgson you are absolutely right and I appreciate you making the effort to keep things going and out of our landfills. We really need to get more poeple involved with this way of thinking. We need to continue to help each other out fixing stuff instead of replacing. Let us know how the new power board works out for you.

door

3 commentaren meer tonen

Voeg een opmerking toe

Opties

ive got very similar tv here Toshiba 40L1333B, when you turn it on, the backlight comes on for a split second and turns off/stays off. If you shine a torch at the screen you can see a picture.

any idea’s. im an experienced electronics engineer, this is a relatives tv and i dont have time for look at it tbh.

Thanks

Col

Was dit antwoord nuttig?

Ja Nee
Score 0

2 opmerkingen:

S***T should i of started my own thread?

door

Hi, the issue will be with the LED backlight strips.

door

Voeg een opmerking toe

Voeg je antwoord toe

Sam Hodgson zal eeuwig dankbaar zijn.
Weergavestatistieken:

Afgelopen 24 uren: 1

Afgelopen 7 dagen: 13

Afgelopen 30 dagen: 42

Altijd: 4,091