Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

[sordids999]

Trying to repair this t.v.

Stuck in standby blue led but no backlights

384v across main cap
LED voltage 130volts when first turned on and stays steady
12 volt going across main tcon fuse also tried a replacement tcon I had as a spare
Power supply megmeet mp550d-dx2
main board t.ms6308.71
pictures uploaded

Thanks

[R_J]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

If you have led voltage going to the led's and no backlight I would suspect open leds in the panel. Without any current draw from the backlights, the driver will error and turn off

[sordids999]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

That's what I was thinking really hate stripping these panels

Thanks

[sordids999]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

Update #
Tested all leds and no shorts so back to the drawing board

[sordids999]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

Legend pins PSU

12v = 12v
12v =12v
Sgnd
Sgnd
Sgnd
+5v =5v
+5v =5v
+5vsb=4.9v
Pson=4.1v
+5v =5.0v
+5v= 5.0v
Sgnd
Sgnd
12v=12v
Bk=4.9v
Adj=4.4v
Sgnd
Sgnd
Led+=130v
Led-=0.00

[budm]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

Led+=130v
Led-=0.00
That indicate open circuit some where in the LED string/wiring.
That LED - is measured with ref. to chassis GND, correct?
LED - is the Cathode return, you have 130V feeding the Anode of the LED string but nothing coming out on the Cathode return.

[sordids999]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

Led+=130v
Led-=0.00

That LED - is measured with ref. to chassis GND, correct?

Yes correct

[dick_barton]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

I wonder if you have a led strip connector problem resulting in an open circuit?

[sordids999]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

I'll tear it.down again this week

[budm]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

I would invest $30 ~ 40 for the LED tester.

[Andrew F. Ali]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

I would invest $30 ~ 40 for the LED tester.

+10 Very useful tool.

[Andrew F. Ali]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

I wonder if you have a led strip connector problem resulting in an open circuit?

Connector/connection problem.

[sordids999]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

I have tested all the wiring for continuity which is good
Used a 6v tester on each led all good
Checked connections seem good
So totally lost here now
How would a led tester help me more ?

Thanks

[sordids999]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

Right back light led tester arrived today
If I test the led strip at the end test points
6 out of the 12 work but the bit I'm confused is if I test every led individually there fine on the faulty strip

Thanks

[Andrew F. Ali]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

If the entire strip of left side and right side connected show only 6 out of 12 LEDs working bit tested good individually then it stands to reason that you have a connector issue Fix this by soldering jumpers to make a positive connection and re-test wiyh the backlights tester and all 12 LEDs will work.

[sordids999]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

Yes it's the 6 to the right which is the side where the connectors go where do I jump from the main connectors ?

[sordids999]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

https://youtu.be/FdibabTYo_M

[Andrew F. Ali]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

No not at the main connector. Jumper at the connector in the middle where the two strips join.

[dick_barton]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

+1 Resolder or bridge the center led strip connector.

[sordids999]

Re: Blaupunkt 49/235Z-GB-11B-FGU-UK blue standby light

Right so I bridged the centre connector and tested with led tester but still nothing
If I use the led tester on the positive side then move the negative lead to each led they light up in sequence but if I try the positive and negative tester points nothing
Remember the left side all six strips work using the led tester but the 6 right side which where the current goes through does not work