Sharp Aquos LC-60LE600U no power period

[budm]

Re: Sharp Aquos LC-60LE600U no power period

Budm, heres the picture of the whole backside of the TV showing all boards connected together.

I replaced the defective bridge rectifier, blown fuse, .56 ohm resistor and the zener diode. After shorting PD 14 and 15, I can see that the pf capacitors are getting the proper voltage of 400V. Connecting all of the boards together when I connect to power, the white LED turns on, backlight turns on momentarily before turning back off. atleast 1 step forward

So at this point what are the Voltages on the PD pin of the power supply board when TV is OFF and when TV is turned on?
Make sure to put down pin name and follow by the reading for each pin so we can easily see what it does or does not have.
Also, are you getting the LED blinking code?

[Adubey]

Re: Sharp Aquos LC-60LE600U no power period

hi i have the same board and the ic Q7801 is blown out with the cap next to it how do i find a replacement for it?

Thanks in advance

You can desolder it and look at its value.

[AVcentre]

Re: Sharp Aquos LC-60LE600U no power period

hi i have the same board and the ic Q7801 is blown out with the cap next to it how do i find a replacement for it?

Thanks in advance

[Adubey]

Re: Sharp Aquos LC-60LE600U no power period

I still like to know why they put 3.3V Zener on one of the connector PD pin, the Zener may have been damaged due to over Voltage. You need to find out what PD pin is connected to that Zener to be able to verify that you are not having over Voltage condition.
Make sure to count the pin correctly since you have odd and even column pin arrangement.

BTW, can I see the pictures of the whole backside of the TV showing how all the boards are connected together?

Budm, heres the picture of the whole backside of the TV showing all boards connected together.

I replaced the defective bridge rectifier, blown fuse, .56 ohm resistor and the zener diode. After shorting PD 14 and 15, I can see that the pf capacitors are getting the proper voltage of 400V. Connecting all of the boards together when I connect to power, the white LED turns on, backlight turns on momentarily before turning back off. atleast 1 step forward

[Adubey]

Re: Sharp Aquos LC-60LE600U no power period

So did you remove that shorted out diode and then test to verify that PD pin on the main board where the Cathode of the diode is connected to goes to PSON pin 14 of PD connector on the power supply board?
I would expect 5V Zener for clamping the PSON pin, not 3.3V.

Budm, I referred to the following document that gives the circuit diagram. Check it on page number 11.

[budm]

Re: Sharp Aquos LC-60LE600U no power period

Hi.
if real this measure
Pin 24 STB = 0.58 V.
no it's normal, you should have a voltage between 5v and 3.3V.
as you say that Pin 14 PS_ON = 2.07V.
hypothesis?
isn't it that you have a faulty stand by circuit?

https://www.badcaps.net/forum/attach...2&d=1486005691

STB Voltage as reported by original OP is BL-ON control signal.
STB pin for this Sharp TV is not Standby POWER SUPPLY output, it is BL-ON pin that gets the command signal from main board, see the pins description.
BU5V is the Standby power supply pin.

[videocentro]

Re: Sharp Aquos LC-60LE600U no power period

Hi.
if real this measure
Pin 24 STB = 0.58 V.
no it's normal, you should have a voltage between 5v and 3.3V.
as you say that Pin 14 PS_ON = 2.07V.
hypothesis?
isn't it that you have a faulty stand by circuit?

[budm]

Re: Sharp Aquos LC-60LE600U no power period

So did you remove that shorted out diode and then test to verify that PD pin on the main board where the Cathode of the diode is connected to goes to PSON pin 14 of PD connector on the power supply board?
I would expect 5V Zener for clamping the PSON pin, not 3.3V.

[Adubey]

Re: Sharp Aquos LC-60LE600U no power period

its connected between PSON (pin 14) and gnd

[budm]

Re: Sharp Aquos LC-60LE600U no power period

I still like to know why they put 3.3V Zener on one of the connector PD pin, the Zener may have been damaged due to over Voltage. You need to find out what PD pin is connected to that Zener to be able to verify that you are not having over Voltage condition.
Make sure to count the pin correctly since you have odd and even column pin arrangement.

BTW, can I see the pictures of the whole backside of the TV showing how all the boards are connected together?

[Adubey]

Re: Sharp Aquos LC-60LE600U no power period

thx Budm, I found its 3.3V zener diode, 200mW - Panasonic DZ2J03300L

[budm]

Re: Sharp Aquos LC-60LE600U no power period

So what is the pin number of that PD connector the diode is connected to? Once you know that then you can look at the PD pin name of the power supply connector to see what is fed to that pin.

[Adubey]

Re: Sharp Aquos LC-60LE600U no power period

I have attached the picture of the part.

Thanks in advance!

Added one more pic

[budm]

Re: Sharp Aquos LC-60LE600U no power period

I have attached the picture of the part.

Thanks in advance!

What is this board you are referring to?
Can you zoom out so we can see what connector it is connected too? It looks to be protection diode.

[Adubey]

Re: Sharp Aquos LC-60LE600U no power period

I was diagnosing the TV further and found on the board KF905FM04 and found the diode 9601 is bad. Does anyone know whats the value of this diode?

I have attached the picture of the part.

Thanks in advance!

[Adubey]

Re: Sharp Aquos LC-60LE600U no power period

It looks to be 2W but you should measure the dimension to get the correct size.

thx again Budm

[budm]

Re: Sharp Aquos LC-60LE600U no power period

It looks to be 2W but you should measure the dimension to get the correct size.

[Adubey]

Re: Sharp Aquos LC-60LE600U no power period

R7816 is the current sensing resistor connected to the Source pin of the PFC MOSFET, when MOSFET shorted out it will blow that Source resistor, it is 0.56 Ohm Flame proof type resistor, you can use MOX (Metal Oxide) power resistor.

Budm, what is the wattage of this resistor? 1W or 2W?

[Adubey]

Re: Sharp Aquos LC-60LE600U no power period

I was dignosing the TV further and found on the board KF905FM04 and found the diode 9601 is bad. Does anyone know whats the value of this diode?

[Adubey]

Re: Sharp Aquos LC-60LE600U no power period

R7816 is the current sensing resistor connected to the Source pin of the PFC MOSFET, when MOSFET shorted out it will blow that Source resistor, it is 0.56 Ohm Flame proof type resistor, you can use MOX (Metal Oxide) power resistor.

Thank you once again Budm!