Re: Samsung ln40b540p8f flickering
Well that's actually really helpful because I didn't know what the differences between the boards were and wasn't 100% sure the others were compatible.
technicallyartistic
Technical Artis
Last Activity: 01-22-2016, 02:33 PM
Joined: 11-28-2015
Location: Woodinville WA
-
Re: Samsung ln40b540p8f flickering
Eh, we aren't using it until its working right again. I like the idea of fixing stuff when I can, but trouble shooting this kind of stuff is why over my head. If nobody else here has any ideas I might just look and see if I can track down another board.Leave a comment:
-
Re: Samsung ln40b540p8f flickering
So it's worse without the jumper. Like a more sporadic flashing on and off. Like before but not at a constant rate. The screen seems much dimmer on the high energy setting as well.
With the jumper it's still noticeably flickering but more like shutter flicker on an old projector than the on and off strobe before.
So far it's been best with just the jumper on, but I'm guessing there's a reason that isn't good for something on the board.Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Phew. I cleaned off the burnt area and everything seems fine. Just a bit of arcing.
This time it was 394 on the high energy saver.
392 with the energy saver off. Still some noticeable flashing and the clicking noise kinda like a project shutter sound.Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Well I am a damn idiot and forgot to unplug the power from the board before removing it this time. We'll see if I destroyed this or not. I saw sparks and smell burning.Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Yup. Jumper is still in place. I will put in the 1MLeave a comment:
-
Re: Samsung ln40b540p8f flickering
I put on a 470k resistor because the next size up I have is 560k .
On the high energy saver setting is between 409-410. With the energy saver setting to off it's about 406, but it's clicking which I think are the bulbs flickering because the image has a flicker to it with the resistor on. Which is probably what the clicking was last time.Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Without a resistor it's about 39k.Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Ok, so testing the main filter cap it's about 437 dcv with the energy saver setting set to off and fluctuating between around 420 and 430 on the high energy saver settings.
There is a noticeable audible clicking coming from the back now too.Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Ok. So I've got that soldered on. Now plug it back in and check the DCV on the main filter cap?Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Just to make sure I'm following correctly, it's just one resistor in the area to the right. Nothing is going to the two ground pins you circled? Or are we adding a resistor to any one of the pins with the resistor icon to the ground?Leave a comment:
-
Re: Samsung ln40b540p8f flickering
So I'm like 90% sure it says Fan 7503. The 5 kinda looks like a 6 maybe from certain angles and the 0 I can barely make out, but it's probably that. Looks like it says EK something up top. maybe EKO. It's all super worn off and only shows up at certain angles with certain light.
Should I remove the pin I soldered to short the optoisolator pins or leave that for now?Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Well it's been on for about 3 hours now and no flashing on any of the energy settings, so so far so good.
What did shorting the optoisolator do? (other than short it.)Leave a comment:
-
Re: Samsung ln40b540p8f flickering
So is that potentially the issue? Or do we need to check that now?Leave a comment:
-
Re: Samsung ln40b540p8f flickering
So it looks like that's maybe a transistor.
KA
431AZ
J48
I think at least. It was hard to read at that angle being blocked.Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Ok. I soldered on a wire like you suggested. A long wire so hopefully that doesn't make a difference.
Turned it on with the energy saving setting set to off.
At first it was a steady 1.683 v.
After it was on a while and the other modes were flashing it was 1.678 v
On low energy saver setting it was fluctuating between roughly 1.480 and 1.657 v
On the high energy saver setting which has a higher rate of flashing it was fluctuating between 1.510 and 1.652vLeave a comment:
-
Re: Samsung ln40b540p8f flickering
I don't see any bad solder joints off hand, but I don't know if my eye is discerning enough to be able to spot them either.
So I know how to test the mosfets. Is there an easy way to test if the caps are bad or under-powered without plugging it in?Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Of course it's near impossible to read. It looks like BD9893F. Anything else it looked like I couldn't find a data sheet for.
Below that it looks like it says 909 H10
No burn marks or swelling caps anywhere I can see. I've looked the board over a few times now.
You will have to walk me through what the plan is because I only understood what you were referring to with the help of Google before. I've dabbled with Arduino some and some small electronics stuff but not really anything that's been this in...Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Crap. This is the part where I need an oscilloscope now, isn't it?Leave a comment:
-
Re: Samsung ln40b540p8f flickering
Ok. Finally got it doing it. On low it was fluctuating between 377 and 381 volts, but mostly going between 378 and 379. And not at the rate of the flashing. Like every few seconds it goes up and down in voltage while the flashing is much faster than that.
On the high energy save settings it's sitting at a pretty steady 380.
With the energy saving setting off it's sitting at a steady 382 now after having been on about an hour.
And here's a link to the video of it flashing.
[URL="https://goo.gl/photos/AdgrAn7vZnSMVofk7"]https://goo.gl/photos/AdgrAn7vZnSMVofk7[/URL]...Last edited by technicallyartistic; 12-13-2015, 11:01 PM.Leave a comment:
No activity results to display
Leave a comment: