Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

[budm]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

https://www.badcaps.net/forum/attach...8&d=1419537011

OK, the PFC Voltage booster is working.
Now lets find out if you do have BL_ON (ON/OFF) on that 5-PIN connector.
Also report the readings on the DET pin, ADJ M pin.

[budm]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

BTW, the red round fuse FM801 is good?

[AFajitas]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

https://www.badcaps.net/forum/attach...8&d=1419537011

OK, the PFC Voltage booster is working.
Now lets find out if you do have BL_ON (ON/OFF) on that 5-PIN connector.
Also report the readings on the DET pin, ADJ M pin.

Both FM fuses test good. BL on is giving me .014v, ADJM .01v, and DET 5.49v.

[budm]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

OK, so the main board is not sending either the BL_ON (on/off), or the Dimming signal to turn on the inverter circuit.

[AFajitas]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

Time for a new mainboard?

Wow, apparently it's hard to find. The few places I have found it, it's $100+. Not even sure if I want to spend that much. p/n BN94-01040C

[budm]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

You can try forcing on the backlights by using 500~1K resistor between the BL_ON (ON/OFF) pin and the STV6 but you must disconnect that wire going back to the main board and also make the connection AFTER the power switch is activated.
It may need another resistor between the Dim pin also if the backlights still not come on.

Service manual:
http://elektrotanya.com/?q=showresul...at2=schematics

[AFajitas]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

You can try forcing on the backlights by using 500~1K resistor between the BL_ON (ON/OFF) pin and the STV6 but you must disconnect that wire going back to the main board and also make the connection AFTER the power switch is activated.
It may need another resistor between the Dim pin also if the backlights still not come on.

Service manual:
http://elektrotanya.com/?q=showresul...at2=schematics

The power switch doesn't work as it stands. It just blinks 5x immedaitely when I plug tv in, and then does nothing when pressed.

[budm]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

OK, I did not know that.
The main board is not cheap indeed.
Did you try heating the main board with hair dryer for 2~3 minutes and then apply the power?

[AFajitas]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

OK, I did not know that.
The main board is not cheap indeed.
Did you try heating the main board with hair dryer for 2~3 minutes and then apply the power?

No, but I was wondering if it could be a failed solder joint from the TV getting really hot. I will try that today. Does the hair dryer produce enough heat to temporary reflow solder joints?

I have fixed a handful of laptop mainboards by reflowing in the oven until I realized it was probably leaching poisons into food that I cooked in the oven afterwards. Thankfully I've gotten a new oven since.

[budm]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

The heat from hair dryer will cause the ESR of the caps to drop if the caps are not too far gone.
It can also expand the solder joints to make better contact, but not for re-flowing.
I do not believe the heat that deformed the plastic came from the TV by the look of the T-CON board.

[AFajitas]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

The heat from hair dryer will cause the ESR of the caps to drop if the caps are not too far gone.
It can also expand the solder joints to make better contact, but not for re-flowing.
I do not believe the heat that deformed the plastic came from the TV by the look of the T-CON board.

No luck with the hair dryer. I may just stalk the mainboard on ebay and try to find a good deal. I really want to get this thing fixed.

I agree with you about the TCON board as well, nothing inside the TV shows signs of heat damage. Enough heat to melt the plastic like that would have certainly left some kind of damage or discoloration.

[AFajitas]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

I might pull the trigger on the main board soon. I found someone that will sell it to me for $90; still pricey, but I can turn a small profit.

I tried to reflow the main board last night but did it in a really jenky way with a 400 degree pizza stone below the mainboard. Sat it on aluminum balls and tented the whole thing with aluminum foil. I don't have a IR thermometer, but I think it got hot enough to reflow the solder. Still no dice.

I was reading a thread from a year or so ago where you were op, BudM: https://www.badcaps.net/forum/showthread.php?t=26522
That TV uses the same mainboard as this one. Do you happen to still have it? Would be nice for me to test with because it actually powers up.

[budm]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

I parted it out.

[AFajitas]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

Ah okay, didnt know if you hung on to the bad mainboard. Thanks.

[AFajitas]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

Ebay stalking paid off. Found one for 60 bucks.

http://www.ebay.com/itm/Samsung-LN-S...-/181625169121

Will report back once it's installed.

[AFajitas]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

mainboard fixed it! I wish I could fix the melted back casing; people will be very suspicious of this TV now when I try to resell it.

[CapLeaker]

Re: Samsung LN-S4095D - Won't turn on; Power LED 5 blinks - I think I see a problem

Good job! Maybe you can straighten the back casing somewhat out by heating it with a heat gun?