Samsung LE26R73BD Working but no Backlight

[doganator]

Hi,

I have a Samsung LE26R73BD LCD.
The tv turns on and very briefly displays a picture before the backlight fails. I can still see the picture if I shine a torch through the back of the tv.
The tv stays on and seems to operate properly, i have working sound.

I am trying to determine whether this is a fault with the inverter or the psu.

The psu output to the inverter is marked as 24V. When tested the psu is outputting 33V at all times whether a load is present or not.

Is the psu overloading the inverter? Or do I have a duff inverter?

My second question is this:

If it is an inverter fault. Would I be able to replace it with the following:
http://www.ebay.co.uk/itm/INVERTER-F...item3f4c9ba100

This has a completely different part number to mine, but is from the same model of tv.

The only inverter I can find that matches my original is £55. And I may as well throw the thing away at that price.

Many thanks.

[doganator]

Re: Samsung LE26R73BD Working but no Backlight

Pictures Attached

[doganator]

Re: Samsung LE26R73BD Working but no Backlight

I have tested the fuses on the inverter board.

F5 (Pictured) Seems to have no continuity. All others seem ok.

Could the psu outputting 33V to the inverter board have caused the inverter to fail?

If I am going to be looking at a psu & inverter replacement this will not be cost effective.

Id be grateful for some expertise if someone has the time.

Thanks again.

[doganator]

Re: Samsung LE26R73BD Working but no Backlight

Can anyone help with this?

I may be being stupid, if that is the case I am happy to be told so!
I am a novice when it comes to these things so any help would be appreciated.

I am guessing that the psu outputting 33v is not right, can anyone help me identify the voltage regulator on the psu board? Can this be changed?

Thanks again.

[budm]

Re: Samsung LE26R73BD Working but no Backlight

Did you verify that your meter is OK? Was it set to DCV? The battery is good?

[tom66]

Re: Samsung LE26R73BD Working but no Backlight

I fixed one of these a while ago - bad transformer on the inverter (made by DARFON)
This one looks like it uses a different inverter, but still worth checking transformers.
Also check backlight on/off signal (marked BL ON/OFF, BLON, ON/OFF, etc.)

[doganator]

Re: Samsung LE26R73BD Working but no Backlight

Have just tried another meter and low and behold we are getting 24V from the PSU.

One multi-meter in the bin!

As mentioned above I found a bad fuse on the inverter board. Do you think this is likely to be the culprit? If so, I linked above to a board on ebay, any good?

Or possibly a bad lamp?

Many Thanks.

[doganator]

Re: Samsung LE26R73BD Working but no Backlight

B/L Signal reading a constant 5.1V

[tom66]

Re: Samsung LE26R73BD Working but no Backlight

Have just tried another meter and low and behold we are getting 24V from the PSU.

One multi-meter in the bin!

As mentioned above I found a bad fuse on the inverter board. Do you think this is likely to be the culprit? If so, I linked above to a board on ebay, any good?

Or possibly a bad lamp?

Many Thanks.

Yes, a bad fuse could easily cause this issue.