Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

Doesn't look like it has a diagram for main board in the pdf I don't see any traces on the pins except for Vin and Vout(squares) and on top of the pcb, it has SMD resistors in the squares for the Vin and Vout. Should I try and take some pix of the bottom side?

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

Hopefully, it won't be too bad since it wasn't instantly zapped when everything else went out, it was working for at least a month after the zap happened so I'm hoping it's not severe issue.

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

If I can get up some pictures of the bottom of the board, think you can help me trace it out and what to check out?

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

Not really sure what to check next on this. If someone could point out a few key components to check, I'll get the numbers off them and look up the schematics on em and test the points out but just don't know which IC chips to test or if it could even be SMD resistor causing the issue.

I've been looking all over for info on this and even a BN94-02661f schematic with no luck. Anyone have one for this model out there??

Kinda left with no options but to try and fix the board, can't afford a new board on this one. lol

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

Apparently, this board BN94-02640M has the same build as mine. All the IC numbers and board id #'s match along with the part numbers on the components.

Shopjimmy image of the underside.

http://www.shopjimmy.com/media/catal...40m-bottom.jpg

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

Can someone point me to the next thing I should be testing and looking for as to what can cause this issue?

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

I have been playing around with it some more and got the standby light to come on.

Once I plug in the AC, the blue light turns on and goes off along with a click and it does the continues clicking but not more blue standby. I do get a steady 5v standby with it clicking on/off.

No relay clicking or blue standby with mainboard disconnected. Suspected mainboard fault still?

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

After reading about possible processor chip issue on mainboard and others reflowing bn's and were sucessful, this one wasn't.

I tested the CN201 connector on the main board and checked

pin 9 (b13v) clicks off-drops....clicks on-jumps to 17v

pin 15(b5v) steady 5v

pin 23(b12vs) clicks off/drops...clicks on jumps to 17v

pin 27(a5v) steady 5v




Some how during these tests again, I did something and now when the tv clicks ON, the screen(backlight) flickers really fast once the relay clicks and goes right off and then you hear the rely click off.

Also took another reading on the CNM802

1--pwr on/off---12mv clicks on/barely goes to 1.0v for split second
3--standby 5.2v----5.2v
5--GND
7--18v---17v
9--GND
11--GND
13--5.3v--5.1v
15--5.3v--5.1v
17--GND
19--12v---12.7v
21--12v---12.7v
23--BL on/off----0.550v clicks on/jumps to 04.57v
25--P DIM----3.3v
27--120vsens---low jumps to 05.57v
29--N.C-----n/a

Anyone have any ideas here?

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

Can someone please help me by circling out some components to check? I can't seem to draw out a diagram on where these traces go from the on/off pin. It seems like everything else is working but the on/off control on the board.

I've looked up a lot of the IC's via part # and pulled the schematics on those to see what they are/do but most are just ethernet and audio that I've found, so not sure a fault in that circuit would cause the issue I'm having. Or if it's a main IC, where is that located on this board?

I did notice this morning that there seems to be some water damage on the RCA shields, on the white and red audio inputs. No corrosion or damage on the PCB.

They did mention their 150gallon water tanks busted which was salt water that was somewhere near the TV. No clue if this plays a role in this issue but I have cleaned the board and reworked it with no luck. I've repaired several water damaged macbooks and laptops but never any TV's. Really need to get this one working so I can either sell it to pay bills or my other one lol

[Ashroyer05]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

Wish I could help. Won't be the first time someone helps you along and then falls off somewhere. Although, Bud is probably busy helping someone else.

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

After some more probing around, I accidentally stumbled across something different.

IC202 on top side by the CN201 side is a small 5 pin regulator or transistor?

I got steady 5.2(Pin1), GND, 5.2, 1.3 and 3.3(pin5) When I went to test what pin 3 was, my probe bridged 2 & 3 and the standby blue led would pop up and screen would flicker some more off and on kinda deal. Pretty sure this is GOOD component but I'm not sure what it is or what it does. Seems if jumping 5.2v & gnd may be nothing but I did notice more activity than usual and thought someone may have some insight.

Anyone?????????

[mmartell]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

What is printed on IC202 ?

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

Very hard to read it without my mags but I'll give it a shot and see if I can read it shortly.

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

It's still pretty hard to see exactly. No white markings on it and it looks crazy but I can only come up with J-412 or J-12

I looked up some IC's and it looks like this

http://www.aliexpress.com/item/Step-...596998998.html


I found the only other looking component on the bottom side by the RCA jacks, it says IN69D or IN690. Doesn't seem like they match tho.

http://www.aliexpress.com/item/Step-...596984208.html

So the top IC202, if I touch the 2nd and 3rd pin, I'll get the standby LED to flicker on and off and also the screen to flicker some more as well. Kinda speeds up the cycle at times. But I can only see the standby light on the initial plug in, when I touch those pins and when I pull the plug, last click I see a faint blue standby.

Is it normal for a 12v pin to output 17v during start up?

[tom66]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

Are you using DC or AC range on your meter? That is abnormally high.

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

DC on the mainboard b12v pin I believe it is. Clicks off, low, clicks on, jumps to 17v. I was wondering if something that high would cause it to shut back down?

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

Anyone have any ideas what would cause 17v to be where 12v should be on mainboard? I am not sure if IC202 is a step up or down IC or LED driver. Based on what the other ones that looked on the links above, they say those are LED IC and step up or step down IC.

IC202 is in front of the main/psu connector. What IC is usually right in that area?? Really wish I could find a schematic for this board!

[ALR]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

Update: Haven't been able to get anywhere with it really but found a board on Ebay and am going to try and snag it tomorrow as it's cheap. Will post results if this repaired issue when it comes in. Hope I am able to buy as I'm selling my personal 52" to get up funds to buy this board. Someone better not snag it after I sell my tv! lol

[mmartell]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

I haven't reread the thread but are you implying you have 12v at ps but 17v on main board ? Have you verified the ps to be good ?

[jfarmer]

Re: Samsung UN55B8000F Mainboard Issue(Relay Clicking Issue)-Help!!

I have the same issue with a ln46d550. Were you able to get it working?