Samsung 192V Advice or maybe a schemaTICC?

[openmike]

Hi, just found this great forum while I was searching the net for clues about my broken Samsung 192V monitor. I have fixed a couple of displays before (bad caps) but this one is puzzling me.

Symptoms:

not many: screen stays black after switch-on, no flicker but power LED stays on. Flashlight test doesn't show any faint image.

What I have done so far:

- checked output voltages to logic board, +5V and +13V are present.
- visually checked all caps for bulging and also measured them, none had shorts or low resistance.
- measured voltage to backlighting tubes: ~1.2 VAC
- the psu board is a BN44-00082A (photo can be found here: http://shop.accessory4you.com/05-cha...-1.asp?id=4130
- the board has a BIT3105 inverter/driver on it. I downloaded the data sheet and noticed that it did not get VDD. Traced it to a section of the board that looked reworked. I desoldered the VDD switching transistor (maybe used for power saving and or dimming) and connected straight to VDD. Voltage on BIT3105 is now 7.3V. Unfortunately still no flicker or sign of life...

My questions:

- if the torchlight test does not show up any faint image, could it be a faulty backlighting?
- there are 4 connectors for the backlighting. Each connector has one thick (pink or blue) wire and a thin (white or orange) wire. There are 4 stacked ferrite inductors near the connectors. Does this mean this screen has 4 backlighting tubes? What voltage should I measure on them? Can I test these tubes easily?

I guess a schematic would be very helpful but other clues would be very welcome...
Many thanks in advance,
Mike

[PlainBill]

Re: Samsung 192V Advice or maybe a schemaTICC?

For a number of reasons, many people here will not go to other sites for pictures. It is suggested you attach them to your next post using 'Manage Attachments' below the text entry area.

The service manual and schematic can be found on Elektrotanya.

PlainBill