LG 47LD500-UA not turning on

[Bill79]

Re: LG 47LD500-UA not turning on

But the O.P. don't says "no 5v"... please be clear when you tag along another one's post, if your case was different it was better to open a new thread, if not threads reaches orribile post numbers like here in this forum happens.. who has wish to read 133 post to come to the point?

Well, this post was started by some one else with the same TV a little bit before I had the problem.
I Googled the symptoms and found this thread on this site with with the same problem with no solution (that I saw).
So, I figured add onto this one so the next guy can find this easy in a Google search and not have multiple threads to choose from.

[Bill79]

Re: LG 47LD500-UA not turning on

OK, so to be sure, if you run the power supply board by itself without having main board connected to it, you do not get any 5vdc, correct?

Yes, that is correct.

[Bill79]

Re: LG 47LD500-UA not turning on

Check the White rectangular fuse F102 (T4A H 250V).

First thing I checked.Fuse is good.
I am looking through your guides right now.
It will take a minute to go through.

[budm]

Re: LG 47LD500-UA not turning on

You have two fuses, so both fuses are good then and you have 160VDc on both ends of that F102 fuse (with ref to the hot side circuit GND) that feeds the B+ to the standby power supply section.

[Bill79]

Re: LG 47LD500-UA not turning on

You have two fuses, so both fuses are good then and you have 160VDc on both ends of that F102 fuse (with ref to the hot side circuit GND) that feeds the B+ to the standby power supply section.

Yes, I have 162VDC at F102 fuse plugged in. And when I unplug, the voltage drops off.
What type of fuse is that for F102?

[budm]

Re: LG 47LD500-UA not turning on

I cannot tell from the pictures but it is Time Delayed type (Slo-bo) fuse.
So at this point we know we have 160 Vdc feeding the STBY SMPS IC (the multi-pin to-220 case) mounted on the heatsink.
What is the P/N of that SMPS IC?

[Bill79]

Re: LG 47LD500-UA not turning on

I cannot tell from the pictures but it is Time Delayed type (Slo-bo) fuse.
So at this point we know we have 160 Vdc feeding the STBY SMPS IC (the multi-pin to-220 case) mounted on the heatsink.
What is the P/N of that SMPS IC?

I am not sure I understand this request.
I am unclear on the "STBY SMPS IC (the multi-pin to-220 case) mounted on the heatsink" specifically.

[budm]

Re: LG 47LD500-UA not turning on

It is the U101 you indicated in your first post, that is the SMPS (Switched Mode Power Supply) IC that produces the 5VSTBY Voltage.

[Bill79]

Re: LG 47LD500-UA not turning on

It is the U101 you indicated in your first post, that is the SMPS (Switched Mode Power Supply) IC that produces the 5VSTBY Voltage.

That is what I thought you meant. I guess too I was checking myself there.
So I see you saw that reply. Good. Something has been bugging me about U101 this entire time I had this TV open (as per my description).

The numbers on that semiconductor are DA23AH (right before that number there appears to be a Foxconn "F" F before it. (Or atleast to me the F reminds me of a Foxconn F).

Under that number there is another number. It appears to read Q0465R.

I hope this is the info you need.

I have always suspected that semiconductor. But wanted to learn if there was a proper way of testing that since it had 6 legs to it into the board.

[Davi.p]

Re: LG 47LD500-UA not turning on

Foxconn chip?? Naahh...! It is Fairchild maybe..

[Bill79]

Re: LG 47LD500-UA not turning on

Foxconn chip?? Naahh...! It is Fairchild maybe..

Now that is a possibility!

[budm]

Re: LG 47LD500-UA not turning on

That is what I thought you meant. I guess too I was checking myself there.
So I see you saw that reply. Good. Something has been bugging me about U101 this entire time I had this TV open (as per my description).

The numbers on that semiconductor are DA23AH (right before that number there appears to be a Foxconn "F" F before it. (Or atleast to me the F reminds me of a Foxconn F).

Under that number there is another number. It appears to read Q0465R.

I hope this is the info you need.

I have always suspected that semiconductor. But wanted to learn if there was a proper way of testing that since it had 6 legs to it into the board.

https://www.fairchildsemi.com/produc...FSQ0465RS.html

Start checking Voltages at the pins of the IC.
BTW, you did test the rectifier diodes on the cold side, the three that are mounted on the heatsinks next to the connector that goes to the main board, right?