Sony KDL-55NX723 suddenly 4 blinks

[PowerAmpFreak]

This Sony KDL-55NX723 can work for minutes to days and suddenly give 4 blink code.
What can be wrong ?

[zomi]

Re: Sony KDL-55NX723 suddenly 4 blinks

Dry joint maybe
go over all joints on power boards
and on the led driver board where power is supplied from the psu boards.

Had a simialr issue on a 55ex720
did the above and has been good for last couple of months.
before was shuuting down daily flashing.
Its happens on some of there maybe you have issue.

[PowerAmpFreak]

Re: Sony KDL-55NX723 suddenly 4 blinks

Could not find any dry joints. Solderwork seems good.

[dskall]

Re: Sony KDL-55NX723 suddenly 4 blinks

Try heat/cool boards. See if you can replicate the problem.

[keeney123]

Re: Sony KDL-55NX723 suddenly 4 blinks

This Sony KDL-55NX723 can work for minutes to days and suddenly give 4 blink code.
What can be wrong ?

Reset to factory default. Measure power board voltage.

[freakaftr8]

Re: Sony KDL-55NX723 suddenly 4 blinks

Probably defective led driver board. Any dark spots in the picture before it turns off with the Four blinks? I had a 55hx729 do the same thing to me and I replace the LED driver board in a problem was solved. BAd ic driver on that board it was cheaper for me to replace and repair

[PowerAmpFreak]

Re: Sony KDL-55NX723 suddenly 4 blinks

No luck finding out the problem.
I want to measure the 'ERROR' signal on the led driver board in order to verify this is the problem first of all.
Anyone know where to monitor the error signal and what state it should have ?