No Stdby Light Samsung Ue46d5000

[budm]

Re: No Stdby Light Samsung Ue46d5000

Right we know that we have the power supply board problem (no other boards connected to the power supply board) due to fluctuating A5V which looks like it is caused by excessive current draw by the IC.
We still do not know if you have the main board problem or not.

[Fritz23]

Re: No Stdby Light Samsung Ue46d5000

So I bought a new ICM801 and replaced it.
A5V is unstable and the clicking noise is still there.

[budm]

Re: No Stdby Light Samsung Ue46d5000

So I bought a new ICM801 and replaced it.
A5V is unstable and the clicking noise is still there.

So the A5V is still unstable when no other board connected to it, right?
Need to look further in that section where the ICM801 is. I will have to look at the diagram further.

[Fritz23]

Re: No Stdby Light Samsung Ue46d5000

So the A5V is still unstable when no other board connected to it, right?
Need to look further in that section where the ICM801 is. I will have to look at the diagram further.

Correct. Thank you

[budm]

Re: No Stdby Light Samsung Ue46d5000

Do you have some caps in stock?
I would like you to replace cap CM812 (10uf 50V), CS805 (47uF 50V) to see if the A5V will become steady.

[Fritz23]

Re: No Stdby Light Samsung Ue46d5000

Sadly I don't have these in stock, but I can order some.
Do they need to be any Low ESR type or something?
How will CS805 influence it?

[budm]

Re: No Stdby Light Samsung Ue46d5000

They should be. What caps do you have in stock?

[Fritz23]

Re: No Stdby Light Samsung Ue46d5000

Capacities >470uF but none is capable of 50V+

[Moreno83]

Re: No Stdby Light Samsung Ue46d5000

My 40D5000 also had a bouncing voltage going to the mainboard. Just powersupply connected to the mains turned the backlight on. You probably already tried that right?

Reecey is right , the mainboard cpu gets really hot and the heatsink is to small.

[Fritz23]

Re: No Stdby Light Samsung Ue46d5000

Yes it turns the backlight on, but it turns of instantly again in an endless loop.

Is there any way to check the mainboard? Could it be really shorted or just a bad solder joint on the cpu? How many pins are under the cpu? Did anyone try to reball it?

[Fritz23]

Re: No Stdby Light Samsung Ue46d5000

Do you have some caps in stock?
I would like you to replace cap CM812 (10uf 50V), CS805 (47uF 50V) to see if the A5V will become steady.

Hi again

I replaced both of them. A5V not stable.

[Fritz23]

Re: No Stdby Light Samsung Ue46d5000

*push*

[Fritz23]

Re: No Stdby Light Samsung Ue46d5000

Does nobody else have an idea?

[budm]

Re: No Stdby Light Samsung Ue46d5000

Sorry, I ran out of ideas, I still think something is loading the down the VCC line produced by the AUX winding of the standby transformer that supplies the switched VCC to the LED driver circuit.

[dick_barton]

Re: No Stdby Light Samsung Ue46d5000

I tried to jumper the PSU (PS_On and A5V, which seemed to be 5V_SB), but this killed a small Transistor. The PSU still works.

What did you replace this transistor this with?

I found a damaged double Z-Diode (for the CI) on the mainboard and soldered it out.

Again what did you replace this with?

[Fritz23]

Re: No Stdby Light Samsung Ue46d5000

Sorry, I ran out of ideas, I still think something is loading the down the VCC line produced by the AUX winding of the standby transformer that supplies the switched VCC to the LED driver circuit.

Okay, thank you for your time. I'll try some things.

What did you replace this transistor this with?



Again what did you replace this with?

I did replace both boards with new, used ones.

[Fritz23]

Re: No Stdby Light Samsung Ue46d5000

Okay, I surrender.

I couldn't find the fault the last time and i couldn't find it this time even with your help.

Now by accidentally shorting Lvcc and Hvcc of ICM801 I probably killed it and some other stuff around it too.

At least A5V is now dead stable at 5.2V

Fucking Trash

[Moreno83]

Re: No Stdby Light Samsung Ue46d5000

The tv provides a good image when it works but the cpu gets really really hot. I had to reflow it 2 times to get it to work , still working at the moment.

You going to buy a new psu?

[Fritz23]

Re: No Stdby Light Samsung Ue46d5000

Hey guys,

I've got a small update for you:
I just bought a new PSU (BN44-00473B instead of "A"). The PSU appears to be working fine but the TV is still completely dead.
I checked all voltages while everything was connected and they seem to be okay.

The two voltage regulators (IC206_T5V: 178M09 and IC706_T5V: LD1117AG) get pretty hot but there is absolutely no sign of life. Even the PSU doesn't switch off.

Any ideas on this?