Samsung UN55B6000 FXZA Inverter?

[agriffin]

Hey guys, really appreciate the knowledge you all share on here. I had a Samsung monitor a few months back that fried itself, a simple search on the forum here and $12 in capacitors later I was able to get it back up and working....this one might be a little more challenging.

The symptoms of the problem follow...

Appears that half or so of the brightness is lost in the screen, the picture is viewable if brightness and contrast are turned all the way to the extreme highs.

Color gambit is also changed, mainly the menus appear a red hue instead of the normal blue (obviously extending into programing)

I hobby in computer repair and it looks like inverter fails that I've seen on laptop computers, or very similar at least; but I see nothing inside the back panel that resembles an inverter. I'm assuming it's built into one of the 3 boards that are there.

I know that blown capacitors don't always show anything, but there's a crap ton on the main board, I didn't want to jump into that if it was obvious to you guys that it was something else. I'll make a point to get shots of the actual screen here when I put the rear panel back on.

All the caps I see are of the Sam Young or Rubycon make. Any help you guys could give me would be awesome! This TV has already been warranty replaced by Samsung, I just didn't have the heart to throw the old one into the dumpster when I suspect the panel on this $2k TV is working perfectly.

Pics follow.

[agriffin]

Re: Samsung UN55B6000 FXZA Inverter?

Pics

[agriffin]

Re: Samsung UN55B6000 FXZA Inverter?

more

[PlainBill]

Re: Samsung UN55B6000 FXZA Inverter?

Dude, seriously, didn't you look at the specs on this TV? This TV uses LEDs for backlighting. No inverter.

PlainBill

[agriffin]

Re: Samsung UN55B6000 FXZA Inverter?

Ah, well I actually did know it was LED back-lit....I didn't realize that LED's don't use inverters.

I didn't even know if lcd tv's or desktop monitors have inverters since they convert dc to ac....and non-laptop screens should be ac form the source.

[agriffin]

Re: Samsung UN55B6000 FXZA Inverter?

I guess I never asked a question....is this something you see as a possible capacitor problem or is there something else on the main power board that might effect the screen brightness? Is there such thing as losing a bank of LCD lights, like say every 3rd?

[PlainBill]

Re: Samsung UN55B6000 FXZA Inverter?

I guess I never asked a question....is this something you see as a possible capacitor problem or is there something else on the main power board that might effect the screen brightness? Is there such thing as losing a bank of LCD lights, like say every 3rd?

Well, since 'white' LEDs are actually a combination of three LEDs, yes it may be possible to lose a bank. It depends on the design. I don't have enough information to even guess.

PlainBill

[agriffin]

Re: Samsung UN55B6000 FXZA Inverter?

Following are actual screen images of the built in test image. It appears to be a brightness issue, not a color, at least to my eyes.

Has anyone seen anything like this on LED TV's?

[agriffin]

Re: Samsung UN55B6000 FXZA Inverter?

Looking at the boards in the back of the TV, posted in pic 1. I'm assuming that that central tan pcb is the power regulating unit with the 2 cables running up to power the panel itself, I see no damage and the cables are attached...of note we were watching the tv and there was a POP sound when the picture dropped.

Is there a way to see if I'm getting correct power out of those?

[PlainBill]

Re: Samsung UN55B6000 FXZA Inverter?

Looking at the boards in the back of the TV, posted in pic 1. I'm assuming that that central tan pcb is the power regulating unit with the 2 cables running up to power the panel itself, I see no damage and the cables are attached...of note we were watching the tv and there was a POP sound when the picture dropped.

Is there a way to see if I'm getting correct power out of those?

Possibly. Download the service manual. It may have the information.

PlainBill

[agriffin]

Re: Samsung UN55B6000 FXZA Inverter?

I actually pulled that service manual before jumping in, it's pretty sparse as far as useful information goes. Looks like the SMPS board, where the power comes in, connects directly to the panel. That is the board with all the capacitors on it.

Does it look like there's other components on there that might be bad that could cause this...or would it just be capacitor problems?

[PlainBill]

Re: Samsung UN55B6000 FXZA Inverter?

I actually pulled that service manual before jumping in, it's pretty sparse as far as useful information goes. Looks like the SMPS board, where the power comes in, connects directly to the panel. That is the board with all the capacitors on it.

Does it look like there's other components on there that might be bad that could cause this...or would it just be capacitor problems?

I doubt it is a capacitor problem. One thing I did encounter today might shed a little light on the subject. The Service Manual for the Viewsonic VX2450MW monitor has actual schematics that give clues about the operation of an LED backlighting system.

PlainBill

[rayrod81]

Re: Samsung UN55B6000 FXZA Inverter?

If you heard a pop then you most likely have a component that shorted directly to ground. You will have to go through the power supply and check the mosfets, voltage regulators, diodes, etc. to find it.

[truep]

Re: Samsung UN55B6000 FXZA Inverter?

Hey Plainbill,
Every time I go to electrotanya, it wants me to load a pdf viewer. Any way around that?

[PlainBill]

Re: Samsung UN55B6000 FXZA Inverter?

Hey Plainbill,
Every time I go to electrotanya, it wants me to load a pdf viewer. Any way around that?

I don't have that problem. I'm running Firefox 5.0 on Win7, but it worked the same way when I was running Firefox 3 on WinXP.

Here's what I do: I click on the link I posted above. It takes me to Elektrotanya. Just to the left of where it says ' VIEWSONIC VX2450W....' is a blue arrow pointing down. Click on that. A new page opens. About 1/4 of the way down it says 'Get Manual' Click on that and the standard download dialog box opens.

I had noticed it is sometimes flakey if you aren't a member. Since membership is free, I solved that problem by signing up.

PlainBill

[jettboat]

Re: Samsung UN55B6000 FXZA Inverter?

I just got this model in with a double image even in menus also not picking up any inputs so aiming toward the main board has a issue & not the t-con

[mmartell]

Re: Samsung UN55B6000 FXZA Inverter?

You may have a problem in the led driver circuits, upper right of pic2. Is the lighting thats there even or uneven across the screen ?