Samsung LCD Screen Issue LN40B530P7F LN40B530P7FXZA

[shortnstubby]

http://youtu.be/gO8m2AuK5NA - A video I made to make this explanation plain and simple.

Model No: LN40B530P7F
Model Code: LN40B530P7FXZA

Issue: When turning on tv, start up audio plays, Red LED begins to flash for a total of 5 times and then goes out, the screen also comes on for approx 1 second then off for 5 seconds it does this about 4 times then the screen stays black. I then can push the power button and it makes the sound of the tv shutting off.

The menu only shows when rest of the picture can be seen.

TV history is unknown for it was given to me, but I believe it was ran pretty much 24/7 till began to have issues.

I have done some research and this seams to be a common issue with this model of tv how ever most everyone has had burnt transformers on the power board and this does not seam to be the case here as I have recorded my ohm readings at 02:01 and seams as if they are within acceptable range.

I do not have the correct equipment to completely test capacitors as well but have done the dmm test by going to ohms and charging the capacitor and reversing my leads and watching the numbers go negative then to positive and all capacitors reacted as I would expect.

If there are any other tests or ideas on what I should dig into I would be very thankful in the help I get.

Thank you.

[shortnstubby]

Re: Samsung LCD Screen Issue LN40B530P7F LN40B530P7FXZA

Is there any other boards I should dig into and test for this issue I'm receiving? Also I am planning to check all the voltages, I found the service manual and it shows the pin outs of where to check for each voltage so am going to give that a try. If there is anymore info I could provide to begin to dig deeper into this issue it would be greatly appreciated. Thanks

[R_J]

Re: Samsung LCD Screen Issue LN40B530P7F LN40B530P7FXZA

You could have a bad ccfl lamp in the panel, that could also shut down the inverter.

[tibimakai]

Re: Samsung LCD Screen Issue LN40B530P7F LN40B530P7FXZA

I have just repaired two of these, but one unfortunately had a T-con issue with the AS15F chip and after replacing it I have noticed a yellow vertical line on the screen.
Moving around the tabs, didn't have any effect on it, then the same chip when't out again. I have just put it in the the trash after I have removed everything that I needed from it.
The other one, seems to have a pretty similar issue as yours.
It was turning on and then only the backlight would turn on and off(not the whole TV).
I have found an open inverter transformer and one which was pretty low, like yours with that 1099 Ohm and after changing them out, the TV is running fine now.
Maybe, somebody can confirm that value, but to me it looks to low.

[shortnstubby]

Re: Samsung LCD Screen Issue LN40B530P7F LN40B530P7FXZA

You could have a bad ccfl lamp in the panel, that could also shut down the inverter.

Question about what you said. If I had a bad lamp would I be able to tell by having a darker spot on the screen?

I have just repaired two of these, but one unfortunately had a T-con issue with the AS15F chip and after replacing it I have noticed a yellow vertical line on the screen.
Moving around the tabs, didn't have any effect on it, then the same chip when't out again. I have just put it in the the trash after I have removed everything that I needed from it.
The other one, seems to have a pretty similar issue as yours.
It was turning on and then only the backlight would turn on and off(not the whole TV).
I have found an open inverter transformer and one which was pretty low, like yours with that 1099 Ohm and after changing them out, the TV is running fine now.
Maybe, somebody can confirm that value, but to me it looks to low.

Now your statements give me some hope, when your talking about having an open inverter transformer your talking one of the 3 white transformers show no resistance? You mentioning that the 1099 sounds low, does anyone know what these are new or a set ohm that it should read? Now that you say that, the one that reads 1099 is a bit lower than the other 2 white ones, but I believe a up close view and the 2nd line of numbers/letters are a bit different. I think I may just order a transformer and then replace the caps and see if that does the trick. I'm willing to blow 10-15 bux to possibly fix a TV for the bedroom that didn't have one lol.

Here is the White Transformer on far left that reads 1099,


This is the transformer that the 2 center white ones are identical to, also both read a bit higher than the one on the left.


Thank you for your help, gives me inspiration I may be able to fix this.

[phrax]

Re: Samsung LCD Screen Issue LN40B530P7F LN40B530P7FXZA

shortnstubby,

Were you able to fix it? I've got the exact same model with similar symptoms.

[johnboy1313]

Re: Samsung LCD Screen Issue LN40B530P7F LN40B530P7FXZA

https://www.badcaps.net/forum/showthread.php?t=33796

[tvtimmy]

Re: Samsung LCD Screen Issue LN40B530P7F LN40B530P7FXZA

I had a problem with the same tv. The thing would start up and make the Samsung chime, but the backlights would only light up for 1 second. I stripped it down to the bulbs and found 4 with 1 inch black stripes on both ends. Those carbon stripes cause the board to take more juice than usual, and shut down the inverter part. I had a junker 40" with 20 lamps in it, so I replaced my 14 in this tv and everything is good.
My advice is, if you get a tv with a busted screen, harvest the parts, inc. the bulbs. I cant tell you how many bulbs I didnt save.