Belinea BT 10003 (1925 S1W)

[rtstorm]

Hi, i got LCD monitor that wont turn on. It was just blinking LED.

I replace 3 blown caps, and monitor wont turn on the backlight and when i flash it with flashlight i see that there is some vertical line on display. On PSU output i have only 4.8V to 5V (no 12V)

Please help me,

[rtstorm]

Re: Belinea BT 10003 (1925 S1W)

i check, all lamps and they are OK. I also notified that LED power does not turn on

[rtstorm]

Re: Belinea BT 10003 (1925 S1W)

here is what i check so far, i dont get how can i have 0V on secundary and 5V on output.

Is this normal 5V or do i have to have 12V?

[rtstorm]

Re: Belinea BT 10003 (1925 S1W)

is it possible the IC driver does not turn on transformer?

[budm]

Re: Belinea BT 10003 (1925 S1W)

Since you are getting the 5VDC, that means the transformer is being driven, there are another winding on the transformer for the 12V, you checked one of the two rectifiers on the heat sink. How is the other rectifier on that same heat sink.
Please post good clear straight shot pictures of the both sides of the board.
Those 0 readings on the transformer output are due to high frequency AC which your meter cannot properly measure due to low bandwidth of your meter.

[rtstorm]

Re: Belinea BT 10003 (1925 S1W)

i check the other rectifier and it is OK, here are the pictures of both sides.

[rtstorm]

Re: Belinea BT 10003 (1925 S1W)

hi, i found that marked diode is bad (run current in both ways), and when i test the voltage regulator (K3562) near it, it can run from pin 3 to pin 2, and from pin 2 to pin 3 not. But when i touch the pin 1 while holding on pin 3 and get back to pin one i measured short voltage for a second and then back to nothing.

What i wanted to ask, wil current run from pin 2 to pin 3 only while pin 1 is provided with current or i can just touch it?

[rtstorm]

Re: Belinea BT 10003 (1925 S1W)

so i tested other components near by and found another diode fail, all other components are ok.

[budm]

Re: Belinea BT 10003 (1925 S1W)

I need straight shot of the WHOLE board, both sides so I can trace out the connections.
The circuits in the primary side are fine otherwise you will not be getting any 5VDC right now.
I can see cold solder joint on the transformer pin for the 12V. Remove the old solder and use flux and new solder.
You should inspect all the joints real close.

[rtstorm]

Re: Belinea BT 10003 (1925 S1W)

here it is:

[budm]

Re: Belinea BT 10003 (1925 S1W)

Please see post 9 picture.

[budm]

Re: Belinea BT 10003 (1925 S1W)

Repair the solder joints and check the fusible resistor.

[rtstorm]

Re: Belinea BT 10003 (1925 S1W)

thank you, it worked i got 12V. You have an eagle eye

[budm]

Re: Belinea BT 10003 (1925 S1W)

Great, thank for the repair feedback, this is why good clear pictures are important to us, luckily your pictures of that section are good enough for me to see the bad joints.

[robertg]

Re: Belinea BT 10003 (1925 S1W)

Hey.
I have also a BT10003 Belinea screen got fro free.
It works OK, only there is a buzzing/noise which is louder when I increase brightness. I am quite sure it comes from the bigger board.
I already teared down and made pics and think that I identified some bad caps.
Shall I post pics in this thread or open a new one to ask for your help?
Cheers, Robert

[budm]

Re: Belinea BT 10003 (1925 S1W)

Please start another thread, that will be best. Also post good clear pictures of the board.

[robertg]

Re: Belinea BT 10003 (1925 S1W)

OK, I placed my question here! Wait for help ...