Insignia NS-32L240A13 POWER SUPPLY DEAD

[NasTech]

Hello

I check the Power supply found two short MOSFET SMK0825 Replace them with FQPF9N25CYDTU I getting my 5Volts on pin 5Vsb and pin 5V1 reading 2.7volts. How can i startup the Power supply without the Main board because when i connect the main board standby voltage fluctuate between 1 - 2volt. No standby light.

Connect resistor between PON and 5V still not turning on, find a 8pin regulator part number not listed(A6059H) can any cross referrence or help with troubleshooting please assisted.

Please Help

[Escort Eagle]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

No you can not switch on the board without VGA board .

Here -
5VSB, 5V1, 12V, 12V ----> Line out
PWM, PON -------> Line In from VGA Board

And Here is your Datasheet .......

[NasTech]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

Why am i only getting 2.6volts on 5V1

[budm]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

"the main board standby voltage fluctuate between 1 - 2volt" You will have to get the 5VSTBY fixed first if it is the problem or if the main board is drawing to much current.
Run the power supply board by itself without having it connected to the main board, use 500 Ohms 10W resistor between 5VSTBY and GND pin and see if it can handle 1A load and still maintain 5v output. The 5VSTBY may have bad startup/running cap (22~47uf 50v cap, C523 and 3 other small cap to the right of C523) problem. Also check the rectifier diode D511.
5V1 and 12v are switched power supply which are turn on by the main board which requires steady 5V to operate.
You can force on the power supply using 500~1K resistor between 5VSTBY and the PON pin, but right now it will not do any good since the 5Vstby may not be good.
Post good pictures of the bottom side of the board as well. Those 2 MOSFETs are more likey for driving the 12V/5V1 power supply transformer. How are they shorted out, S to D, G to S? The SMPS IC that drives the MOSFETs may be damaged also.

[Escort Eagle]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

I am watching the 5VSB Diode only in the start-up side . Where is the 5V1 Diode in Start-up ?? I also think so - 5V1 is in the Switching side, it is not in the Start-up side .

when i connect the main board standby voltage fluctuate between 1 - 2volt. No standby light.

That means you have a short in the VGA Board . This is why 5VSB is drawing too much current and as a result 5VSB is dropping voltage to 2.6V .

And give us a printed side's picture of the board .

[Escort Eagle]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

use 500 Ohms 10W resistor between 5VSTBY and GND pin and see if it can handle 1A load

budm, Are you sure 500 Ohms can deliver 1A current for 5V ? If we use 10 Ohms for 5V for drawing 0.5A current then will it be risky ?

[budm]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

Sorry, typo on my part, 5 Ohms for 1A. Looking at the size of the Diode and the transformer in that 5VSTBY, it should be able to deliver 1A at 5V. You can use 10 Ohms first also. The spec of the IC is 10W capable.
OK, I see good image at SJ:
http://www.shopjimmy.com/insignia-6m...upply-unit.htm

[Escort Eagle]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

But Resistor will be soooo HOT within 2 or 3 minutes !!!! I think - It will cross 10W within 2 or 3 minutes !!! If it exceeds more than 10W then IC will be definitely burnt out like a chicken fry !!! Even he can not measure the voltage properly within that time . So, I think - Load checking with a Resistor is very BAD idea . It would be best if he could use a 5V, 5W or 6W Bulb as Load tester . By using 5W or 6W Bulb as load tester there is no chance of crossing 10W and damaging the IC .

[budm]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

5 Ohms @5V = 1A, 5V x1A = 5 Watts of power on the resistor (resistor should be rated at 2X of power needed) so how do you get 10 Watts on the resistor? 5V 5W lamp will have hot resistance of 5 Ohms, cold resistance will be about 0.5 Ohms, now that cam be bad when the power supply is turn on when lamp is cold, surge current will be very high.
" Load checking with a Resistor is very BAD idea" I have no idea where you get that info from.

[tom66]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

5^2 / 10 = 2.5W (V^2/R)
A 5 ohm, 10W resistor will be fine...

[Escort Eagle]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

Check Transistor (V506) and it's surroundings Resistors and capacitors . (Shown in the image) . Actually your 5V1 is load sensing and feedback for 5VSB . If this transistor (V506) is bad then 5VSB can drop voltage in Loaded condition .

[budm]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

The 5VSTBY OUTPUT VOLTGAE sense is done through divider resistor network R543/544 which is fed to the Vref Diode that drives the Opto isolator for the feedback to regulate the output voltage, V506 is used as a switch to provide switched 5V1 output.
See simplified diagram, 5V1 is not used for feedback, just a switched output.

[budm]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

Incandescent hot and cold resistance.

[Escort Eagle]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

Then what is his problem !! Why is the 5VSB dropping voltage . Then is it problem in his VGA Board .......

And thanks for sharing useful information @budm.

[budm]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

That is why he needs to load the 5VSTBY with dummy load first, if it can maintain 5V then next step will be checking the main board, just have to find out where the problem is first. I still have a feeling that he may still have the problem in the 12V/24V power supply section due to the fact that two MOSFETs had shorted out, this can be multi-problems on this power supply board.

[NasTech]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

I found a Main Board from shopjimmy but it don't solve the problem

[velasquez05]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

I have this same TV "insignia ns-32l240a13". The tv has no powered it does nothing when I push the power button. I am probably going to start by replacing the caps on the power board. I have played around with some tv repairs and I have always had success replacing the caps. I would like to know you all recommend with starting with the start-up caps C523 and the three next to it or if I should start somewhere else. The caps are not swollen and there are no burn marks but I have had caps look good that were actually bad.
I would also like to know more about how to diagnose the board. For example what readings I should get where on the board and when. I would also like to know how to properly test a capacitor and other parts. I guess I could go to school for electronics at some point but for now I will have to stay a firefighter that tries to tinker with electronics. Thanks for any help you guys can offer.

[japlytic]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

This board has two separate power supply transformers; the main power supply which is switched uses the larger transformer (T501).
The standby supply uses the smaller transformer (T502) and is unswitched.

Also try checking diode D511 for shorts; if the +5VSB rail is still out of tolerance with a load resistor (10R 10W is good), try replacing the units on the +5VSB rail since capacitors can go bad without any external signs.

[velasquez05]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

I have Replaced the power supply board in my Insignia ns-32l240a13 I still have no stand-by light and no power. I would like to post the voltages that I am getting at all of the pins but I need to know if all output from the power supply is DC. I was about to order a replacement main board but I have a feeling that the problem still lies in the power supply. Any help would be appreciated.

[philo]

Re: Insignia NS-32L240A13 POWER SUPPLY DEAD

Could you fix it? Or you had to replace it? Thx