Sceptre X322BCB0359

[nstlfrk]

Re: Sceptre X322BCB0359

OK, we need to check pin 8 (VCC) to see if the IC is getting >12.5VDC typ. to run.
You will use the negative leg of the main filter cap (450VDC cap) as the Ground ref point. You must be REAL CAREFUL because you are working in the primary side, it is not going to be easy since the part is on the bottom side. You should plug the board into GFI outlet to protect yourself.

No problem but to be clear on this can i just plug the main power in or do I need to have all plugs pluged in.
Also does the tv need to be turned on?

[budm]

Re: Sceptre X322BCB0359

You do have to connect everything back together because you need to have PS_ON signal to turn on the PFC circuit, You can test the power supply board by itself by forcing it on but the high voltage section for the backlights may accidentally turn on while you are probing the board, so it is not a good idea.

[nstlfrk]

Re: Sceptre X322BCB0359

Ok it is not getting 12 volts. Shows 0.12 v

[budm]

Re: Sceptre X322BCB0359

OK, I will need really good well focused pictures around that IC to see where pin 8 is connected to.

[budm]

Re: Sceptre X322BCB0359

OK, the picture in post 30, I can see pin 8 has a filter cap positive pin connected to pin 8, then pin is connected to jumper RJ34, the other side of RJ34 is connected to resistor R213, but then the picture is cut out.
See if R213 resistance reading is.

"Ok it is not getting 12 volts. Shows 0.12 v" BTW, TV is on and you still have the other voltages, right? as shown in post 24.

[nstlfrk]

Re: Sceptre X322BCB0359

OK, the picture in post 30, I can see pin 8 has a filter cap positive pin connected to pin 8, then pin is connected to jumper RJ34, the other side of RJ34 is connected to resistor R213, but then the picture is cut out.
See if R213 resistance reading is.

"Ok it is not getting 12 volts. Shows 0.12 v" BTW, TV is on and you still have the other voltages, right? as shown in post 24.

Yes I still have all the voltages as stated earlier
here are some more pics

[budm]

Re: Sceptre X322BCB0359

Check that resistor R213 to see if it is open, check on the bottom side of the board because I think it is mounted under the transformer. One of the R213 leg should be connected to pin 8 of the IC.

[nstlfrk]

Re: Sceptre X322BCB0359

Check that resistor R213 to see if it is open, check on the bottom side of the board because I think it is mounted under the transformer. One of the R213 leg should be connected to pin 8 of the IC.

I nly see R213 one place on the board and it is that jumper.
What am I missing?

[nstlfrk]

Re: Sceptre X322BCB0359

I nly see R213 one place on the board and it is that jumper.
What am I missing?

I dont see a resistor on the line witht he R213

[budm]

Re: Sceptre X322BCB0359

I cannot see it on the top side of the board, you should be able to read the resistance of R213. Is it a jumper? The other end of R213 is connector to the resistor R114 and then the rectifier diode D105 which is connected to one of the transformer (next to IC U701 which drives that transformer) winding to supply the 12V to run the IC.

[nstlfrk]

Re: Sceptre X322BCB0359

I cannot see it on the top side of the board, you should be able to read the resistance of R213. Is it a jumper? The other end of R213 is connector to the resistor R114 and then the rectifier diode D105 which is connected to one of the transformer (next to IC U701 which drives that transformer) winding to supply the 12V to run the IC.

Ok on resistor R114 it measures a dead short like .01 - .02 on the 2K setting on my meter.

[budm]

Re: Sceptre X322BCB0359

OK, so to me it looks like that transformer is not being driven, but you should check out that SMD R114 (20 Ohms?) and the SMD D105 to see if they are OK.
We may have more complicate problem than I thought. Can you read the P/N of that 16-PIN IC U701?

[nstlfrk]

Re: Sceptre X322BCB0359

OK, so to me it looks like that transformer is not being driven, but you should check out that SMD R114 (20 Ohms?) and the SMD D105 to see if they are OK.
We may have more complicate problem than I thought. Can you read the P/N of that 16-PIN IC U701?

Yes the number is
ER3525

[budm]

Re: Sceptre X322BCB0359

That is all what is printed on the IC? It should have lots more than that.

[budm]

Re: Sceptre X322BCB0359

Do you have cap meter to check that cap EC104? Can you also see the value of that cap?

[nstlfrk]

Re: Sceptre X322BCB0359

That is all what is printed on the IC? It should have lots more than that.

ER3525
ATEbY

Thats all that is on the IC

[nstlfrk]

Re: Sceptre X322BCB0359

Do you have cap meter to check that cap EC104? Can you also see the value of that cap?

Sorry to say I do not have a Cap meter.
I do have A couple really nice flukes

22uf 50V

[budm]

Re: Sceptre X322BCB0359

Try replacing that cap.

[nstlfrk]

Re: Sceptre X322BCB0359

try replacing that cap.

that didn't change anything.

[budm]

Re: Sceptre X322BCB0359

I just want to eliminate the possibility. So we need to figure out how that transformer is being driven by that 16-pin IC.