I have the Sony 55nx720 3 times red flashing G6 I checked the SMPS power supply Standby 3.3v pin and 12 volts come out when I bridge the Power on pin What should I check on the motherboard.

The power supply board has gone bad.It would be more cheaper and easier to buy a new TV than to try and fix the TV that is not working.

The main power supply regulator section circuit fault. Either it will be a separate board, or the part of main board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
It will be best to replace the power supply regulator board as card basis rather than making "Surgery" to it; which usually will make loss for both money and time. Even though you can make it right, it will cost around an amount equal to the cost of a new board; including the cost of (spare parts + service charge) More to say, most of the spare parts to it will be difficult to get from open electronic spare part market. This is true to most of the flat panel TV power supply boards; irrespective of its brand and screen size.
Search the site by type in the "brand name" to your device; in the "Search box at the top right of the display window of the Homepage" to get gathered related posts.

The 12 volts comes FROM the power supply board.
TV Parts Universal TV Stands DLP Chips ShopJimmy Go to this web site. You will find repair parts kits as well as complete boards there.

Okay; first off an SMPS is any number of power supplies used for electronics. So this is a very vague question. In a computer power supply to an IBM or PowerPC based motherboard (the later is now obsolete and no longer in use for most new computers) there is no one power supply "wire". Most video cards are powered via PCI port through the motherboard power supply connection.

Some very high power high end video cards and some SLI/Bridged cards require their own power source and this is usually a 12 volt rail much like the ones used for SATA power supply.

In a monitor, each make and model can be different depending on who supplied the power supply. The internal power cords can come in different colors. Though the standards are black white blue and green and red. Most displays don't use colored cords for connecting to the main board of the display. They use a 8 or 10 pin ribbon. Most of the colored wires are linking the main inducer to the LED back light.

If we're talking about the internal workings of an SMPS (Switch Mode Power Supply) there is no "display" wire. SMPS internal wiring is all about controlling and routing power to the different rails (that is the different power connectors). Never open an SMPS case, especially if it's plugged in. Switch-mode power supplies have capacitors that can provide a rather nasty charge, and several inducers that can hold a charge well after the power supply has been unplugged. Never service an SMPS on your own, always seek a professional when attempting to fix an SMPS. Though, for the most part, fixing a burnt out power supply is a waste of time, it'd be best just to buy a new one and recycle the dead one.

http://www.itwinkle.com/hp57posub.html

Nothing special about that Power Supply except for the PRICE!

It's just a regular ATX SMPS with a 575 Watt maximum rate wattage, and an 8-pin EPS +12 Volt power cable.

The HP part number is HP 405349-001
I just THOUGHT the above model was expensive,

http://www.sears.com/hp-405349-001-hp-575watt-power-supply-for-workstation/p-SP101A9790S5492818201P

Uses one 24-pin ATX main power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

One 8-pin EPS +12 Volt power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#eps8

[NOTE*
NOT to be confused with the 8-pin PCI Express power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#pciexpress8

Yellow wires are 12 Volt wires. Black wires are Ground (Negative) wires.
The 8-pin EPS +12 Volt power cable has FOUR 12 Volt wires.
The 8-pin PCI Express power cable has THREE 12 Volt wires ]

I believe 4 SATA power cables,

http://www.playtool.com/pages/psuconnectors/connectors.html#sata

,and a few 4-pin Peripheral power cables, ('Molex'),

http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral

Power Supply case dimensions are approximately
6 Inches Wide, 5.5 Inches Long, and 3.5 Inches in Height.
(152.40mm Wide, 139.70 Long, and 88.89mm in Height )

36 Amps combined for the two 12 Volt power rails.
(12V1 = 18 Amps, 12V2 = 18 Amps)

This is an example of a replacement SMPS,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=899124&CatId=1483

I'm running one of these right now in a Dell Optiplex 745
Yes, even though the power cabling noted on the Tigerdirect ad is erroneous, it DOES have an 8-pin EPS +12 Volt power cable.

One 24-pin ATX main power cable
Four 4-pin Peripheral power cables
Six SATA power cables
One Small 4-pin Peripheral power cable. (Used for a Floppy Drive, or a Card Reader)

Two 12 Volt power rails. 12V1 = 23 Amps, 12V2 = 20 Amps
Combined = 43 Amps on the 12 Volt power rail.

Repair?
Due to the possible electrocution hazard, I don't post info on repair.
I will state;
The capacitors need to be PROPERLY discharged, before attempting to work on the unit.
The Radial Aluminum Electrolytic Capacitors are the weakest link.


For additional questions please post in a Comment.

Regards,
joecoolvette

A Flashing Red ON/STANDBY LED means one of the following
2 Flashes - The internal temprature is high. Check the air holes are unobstructed.
4 Flashes - The fan is broken
6 Flashes - The internal electrical system has failed.
There is no entry in the manual for 12 red flashes.

hi,
you have to check the power supply first.

As u mentioned about the click sound, the 5v standby supply is ok. The click sound you hear is from the standby relay.
you have to check the other power supplies in the SMPS (switch mode power supply board) board.
first of all check the standby supply 5v on tne pin of connector P800. check the voltage at this point in standby condition and at the time of power on. it should stay at 5v. if it reduces the you have to check the components related with standby SMPS transformer T501.

If the 5v volt is ok the u have to check the 3.4 v at the pin 1 and 2 of connector P802, at the time of power on. if it is missing then check the components related to T112 ,also check the following voltages at the same power on condition.

19v at Pin 1and 2 of P803
6v at the pin 5 and 6 of P802
12v at the pin 9and 10 of P802

check these to verify your tv's power supply
proper care should be taken while working with power supply, because there is risk of getting electric shock.
if you need any more assistance fell free to contact me through fixya.
I have with me its field service manual ( does not have any schematics) if u need that i will sent it to you, if u give me your email id through fixya.
ok

I also concur that the power supply is at fault.
Weak voltage power rail.

1) You can check the voltages of the power supply with a power supply tester, (One example: http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5250576&CatId=1107

2) You can also check the voltages with a multimeter.

There are three main voltages produced by a SMPS.
(Switched Mode Power Supply. However the 3.3 Volt power rail is being phased out)

A) Wires with Orange insulation are 3.3 Volts
B) Red insulation 5 Volts
C) Yellow insulation 12 Volts

D) Black insulation denotes a Ground wire. ANY Black wire is a Ground wire. Granted not a power wire, but needed to be stated here with the power wires.

All power cables unplugged inside the computer, power supply still attached to computer case. Power supply is turned on, and the voltages are checked.

Multimeter is set to DC, and the 0-50 Volt scale if applicable.
The Positive (Red) probe lead of the multimeter is connected to a power wire.
The Negative probe lead is connected to ANY Ground wire.

The Voltage power wire of most concern here is the 12 Volt wire.
11 to 13 Volts is okay. Less than 11 volts it's time for a new power supply.

Forget about the individual plugs. Concentrate on the wires.

The Delta SMP - 420BB is just another
Switched Mode Power Supply.

(SMPS shortened to SMP by Delta. I'm speculating here, but I'll bet the 420 stands for 420 Watts)

No matter what the input voltage is, the SMPS will only put out three main voltages.

1) Wires with Yellow insulation are 12 Volts
2) Red wires are 5 Volts
3) Orange wires are 3.3 Volts

ANY Black wire is a Ground wire.

For example:
1) 4-pin white Molex power cable.
1 - Yellow wire
1 - Red wire
2 - Black wires

(4-pin Molex power cable is also referred to as a Peripheral power cable)

Here is more in-depth info about the various power connectors, and power cables, used in a personal computer,

http://www.playtool.com/pages/psuconnectors/connectors.html

do it only if u r a professional..
assuming that the system bios hs not been flashed or updated in a wrong way..if so u gotta replace the m/b..
1st check for ac main supply and fuse..next check all the outputs of smps viz. 0v (black~ground); +12v (yellow); +5v (red, green~ps-on, violet~pg & grey~sb); -12v (blue); -5v(white); +3.3v(orange)..if faulty try repairing or replacing the power supply with a standby n see..
if all above are ok..check the cmos/system battery..(above +3v)..
check the cpu fan rotating and the cpu generating heat..try replacing the cpu with a standby (if no heat is generated)..
there may b a chance for m/b's crystal clock generator to b faulty..try repairing or replacing the m/b with a standby..
hope it'll b enough to solve ur problem..
seek professional assistance of ur system admin/vendor....