Blaupunkt LED TV - No backlight, LEDs repaired but still nothing

I have enough of a "heavy" TP board. MSD309.BP85 - generally it is a Blaupunkt Bla-40 / 133L-WB-5B2-FHBKU_EU TV with LSC400HM06 matrix. On the TV everything works, except for the matrix's backlight (there is sound, the matrix displays the image, etc.).

I got used to the backlight, giving +/- 25V for each of the four LED strips. Two of them did not shine, so, going one by one, came the exchange of a total of three pieces.

Currently, when giving 25V for each strip, all the LEDs light up, so it should be OK - unfortunately, virtually no improvement, while switching on, there is still no backlight. The board has two separate sockets for leds, STBy is 35V, and when switched on it jumps at about 90V and after a while drops to 35V - as far as I know, this is typical for backlight damage, which I fixed, although I know that it would be appropriate to provide external voltage probably 60V to check if they ignite in a set (60V for two stripes) - unfortunately I do not have too much to organize such a voltage, I would like someone to give me an idea for external power supply, and generally for the repair of this TV.

And the slats are connected in what way? There are sometimes breaks at the joints.

At the junctions everything looks fine, I think it would be good to give 60V for one and the other plug to check whether both pairs will ignite, only the maximum voltage I have is 30V, I wonder where and how to organize such a voltage.

chek all led

wentyl215 wrote:

Everything looks fine on the connectors, I think I should give 60V for both plugs to see if both pairs will ignite, only the maximum voltage what I have is 30V, I wonder where and how to organize such tension.

On the familiar website at our friendów there are testers for LEDs and that's what normal work is now.

Do you mean something like the iFix RT300M?

Until then you could think about some temporary solution and connection, but thanks to

Something like this, I have one with volt and amper display, additionally led current change.

wentyl215 wrote:

Currently giving 25V for each bar all LEDs are on fire so it should already be OK

Together or separately they will shine from an external power supply, even if you find one on 100V. You have damaged the other LEDs, or at least one (with an efficient driver and connections). To find a damaged diode, supply each string separately with 25V and start gradually reducing the voltage. Diodes that will turn off or will be less shining than others should be replaced.

Thanks for the hint, I'll check it in a while, by the way I wanted to ask for a driver - will it be UB10 on this CD? OB3350? What tensions are to be on individual feet?

Well, the issue of stabilizers, because one of them - UL1 (1117B) when turning on the TV lets go from 1 leg (GND) to VOUT, it means a transition. Other stabilizers, including those identical under UL11, do not have this symptom.

Another thing is the diode DB13, which goes two ways (diode test), after desoldering it turned out that the diode is OK, the transition between the soldering fields DB13 also present without a diode.

wentyl215 wrote:

I wanted to ask for a driver - will it be UB10 on this disc? OB3350?

Ask Google.

bogred wrote:

wentyl215 wrote:

I wanted to ask for a driver - on this disc will it be UB10? OB3350?

Ask Google.

I asked and confirmed, but I prefer to ask and make sure

Just to this system, complete documentation is available and it is easy to find. And now - act.

wentyl215 wrote:

And the issue of stabilizers, because one of them - UL1 (1117B) when turning on the TV lets go from 1 leg (GND) to VOUT, it means is the transition.

wentyl215 wrote:

Another thing is the DB13 diode , which goes two ways (diode test), after desoldering it turned out that the diode is OK, the transition between the DB13 soldering fields also present without a diode.

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bogred wrote:

And now - act.

With such knowledge?

As I reported, that the topic underestimates the level, if only because of the wrong title of the topic, but not only, you overested me.

Thanks for the transfer - if I'm in the right place, could anyone help me with the topic?

I will help you
https://pl.aliexpress.com/item/110V-265V-LED-...Light-board-LED-light-Tester/32484104001.html
version for lazy
https://www.elektroda.pl/rtvforum/topic3390653.html#16780245
version for more ambitious
and somewhere on the website of "companions" I saw something even more interesting.

It depends on how many diodes there is on the strip and on what voltage is the diode I usually check each separately for two sharp tweezers, connect the power supply and pierce lightly with the laminate in the pads or to check the whole strip I attach power supply from an HP full-size printer it has 32V 940mA and 16V 625mA and with a 32-inch backlight it's enough to light up all one strip.

gradek83 wrote:

It depends on how many diodes there is on the strip and what voltage the diode is usually in, or I check each one separately for two sharp tweezers, plug in the power supply and pierce it lightly laminate in the case or to check the entire strip podinam Zasilacz from the HP printer on full recycling it has 32V 940mA and 16V 625mA and with 32-inch backlight is enough to ignite the entire one strip.

Thanks for the answer, although I mentioned that the 30V voltage I have, where I wrote, that each strip is lit (4 strips probably 10 leds) - the strips are connected in pairs and should be given 60V - I will come back to the subject next week.

Welcome.
I have a similar problem with LEDs on Blaupunkt TV.
I wanted to use "LED module 3 diodes at 12V" 8 pcs of such modules, that is 96V, but it does not work.
When the TV starts up, about 100V diodes are flashing and that's all in the subject. 38V as much as on STB.

Any ideas? Does the driver have to see any particular resistance?

You disassemble the panel and you will see how many defective LEDs. I am trying to exchange for new ones. The possibility of corrections and re-disassembly of panel pozdr is minimized.

kiko_tychy wrote:

Does the driver need to see any particular resistance?

The driver has to "see" a certain number of LEDs with specific parameters for a given backlight model.

kiko_tychy wrote:

"LED module 3 diodes at 12V

Combinations -