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

[CapLeaker]

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

of course. also try to turn it on and see if there is a change

[AFajitas]

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

Cool, thanks. Sorry for the amateur questions; just trying to make sure I don't beef anything up. I will try to plug it in tonight and test the pins, although I'm pretty deep into a bottle of red wine might have to wait until tomorrow. I'll update you guys then.

Thanks for all the help and happy holidays.

[budm]

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

So what is the P/N of the power supply board, bn-??????

[AFajitas]

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

BN44-00140A aka Ip-280135a is the model of p/s. Merry xmas

[leggot]

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

I once had a monitor with a similar problem, it had 2 seconds black issue. Occasionally the backlight would turn on and the corners would heat up, and melted the plastic case. I disassembled it and it turns out that the connection from the CCFL to the wire was charred. I do not know, if this was caused by a similar issue or if it still gets hot, but thats just my own experience.

If the melted part is dead in the middle, it could be that there are multiple CCFL bulbs soldered together and that join is bad.

[AFajitas]

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

Start on the power supply. There is a 26 pin header on the top right of the power supply board. Plug everything back together and test that header with your DMM. The pin outs for it is marked between the 2 transformers and the big aluminum heat sink. Put the negative lead to GND and probe all others. Note the voltages down with the pin numbers and post back.
Don't touch the hot side of the power supply, just that header.

Okay, I see a 30 pin header there and then a legend on the pcb that identifies 32 pins. Which pin is pin 1? It appears that the bottom left most pin has an arrow printed on the pcb.

Thanks for your help.

[budm]

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

That arrow is for pin1 marking, the bottom row is the ODD number pins, the top row is for the EVEN number pins.
It is 32-pin connector.

[AFajitas]

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

I can count them now.

Thanks

[AFajitas]

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

That arrow is for pin1 marking, the bottom row is the ODD number pins, the top row is for the EVEN number pins.
It is 32-pin connector.

The only pins I am getting a reading from are pins 5-10 - they are reading 5.97v. The TV doesnt actually turn on, so Im not sure if that matters for current to be running through some of those pins.

[budm]

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

Can you list the pin labels of the connector so I know what pin 5 and 10 are?

[AFajitas]

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

Here you are.

[budm]

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

Pin 2 is the Power on (PS_ON) is not getting the signal from the main board to turn on the rest of the power supply, it should have >2.5VDC at pin 2 for it to come on.

[Agent24]

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

So it looks like you have the 6v standby rail and nothing else. I wonder if the "12VS" is a standby rail too? If that is missing maybe that is why nothing is happening?

[budm]

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

I think 12VS is the Switched 12V which is turned on by the PS_ON. 12V is usually for Audio circuits and T-CON.

[AFajitas]

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

How should I proceed from here?

[Agent24]

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

I think you have to find out why the mainboard is not sending the PS_ON signal to the PSU.

[AFajitas]

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

Alright, I must be doing something wrong because I am testing the pins with the mainboard unplugged from the header. Should I leave it plugged in, supply power to the TV, then unplug and test?

[Agent24]

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

Pretty sure you need to have everything plugged in and turned on, then measure voltages.

Obviously the 6v Standby rail is OK, but we need to know if the mainboard is sending the powerup signal to the PSU, and if any other rails are coming up OK or not.

[AFajitas]

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

stupid question, but how do I test the pins on the p/s if the cable from the mainboard is plugged into it?

[Agent24]

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

Just push the end of your probe into the plastic housing for the pin you wish to measure, if you probe is pointy enough it will touch the crimp end of the contact. If not, stick something else in the hole first like short piece of solid wire. Of course, make sure not to short-circuit anything.

See the photo attached, you can see where the crimp end of the contact is where it joins the wire.