Sony 55hx823 4 Blinks

[zomi]

Right has 55hx823 gives 4 blinks

From cold sometimes works for 20 mins

then its on and off
Once you power it on again

Leave it a little longer and It may play nice abit longer.

Something not right..

Not had the back off yet
Just playing with it to see how it behaves..

Previously it is supposed to have had the balancer board changed..
----
Service manual is attached

Just one thing if someone could help is

what is the termonology sony use

And the balancer board is the led board yeh ?

B* board
G* board

led board

Could ulitmately be a failed led but I am pzuzzled why at times it runs for 20 mins or so
So hoping it a board issue ..

Will open up tomorrow when I have some helpers and we can see what it does..

[newtothis]

Re: Sony 55hx823 4 Blinks

Open set and take pictures of boards and chassis please

[freakaftr8]

Re: Sony 55hx823 4 Blinks

technically the balancer board is in a way the LED board although the power supply drives the LEDs directly I believe. However I had a TV similar to this and it turned out to be the balancer board. when an LED fails it fails it doesn't come back to life.however a balancer board can give a problem where the LEDs will work for some time and then just spontaneously go out.

[zomi]

Re: Sony 55hx823 4 Blinks

Will update with pictures later today if I can.
Just waiting on helper to help dismantle.

In the meantime..
Led failure should be on/off cycle in a couple of seconds
Even from cold ?

What I have is works for 10 -30 mins then 4 blinks.
then it will just flash on then off..

Leave it to cool for 5mins then It will work again for 10-30 mins...

[zomi]

Re: Sony 55hx823 4 Blinks

here are some internet pics of the inisde of the tv

and the led driver board

its the same as the 46hx823 one.

[nomoresonys]

Re: Sony 55hx823 4 Blinks

could be bad capacitor/s on power supply.

[freakaftr8]

Re: Sony 55hx823 4 Blinks

yep that picture on the right is the led balancer board and those driver ICs are known to fail like I said I've worked on a few of these now with the same problem they're very intermittent but if the LEDs light up then they are good.

of course there is always a chance that you have a short in one of the wires that go to the LED backlights that run into the back frame behind the LCD panel. I've seen that too and that could present a problem as the TV starts to warm up things move in the wire touches ground. What happens when it shuts down with 4 blinks and you immediately disconnect the power and connect it back up and then power it up does it come right back on and play for awhile again? because if that's the case and it does come back on then that would blow my theory about the shorted wire

[zomi]

Re: Sony 55hx823 4 Blinks

No it does not come back on straight away.
Have to leave it a while
Then it works
Had tested it at 5 min intervals

After a few seonds wait it still blinks 4
does that make sense..

Just going to take the back off then wait till it fails then spray the driver ic.
And see what happens..

Are the driver ic's availble as it would make it easier and cheaper..

[tibimakai]

Re: Sony 55hx823 4 Blinks

I have worked on an NX one and the ballancer board looks very similar, if not the same. The IC it was available, but the whole board it was $58 from shopjimmy and I couldn't way for three weeks, for the ICs to arrive from China.
There are test points at each IC, you could compare them and see which one is bad.

[zomi]

Re: Sony 55hx823 4 Blinks

thanks...
Just more one qu
once I remove the back off this tv
I Cant mount it back on the stand can I ?
going to have to rethink my work area..

[freakaftr8]

Re: Sony 55hx823 4 Blinks

Yep that balancer board is identical to a kdl-55hx729 I repaired. It came on with perfect picture for 10 seconds them the bottom right would go out. After that 4 blinks. Like tibimakai said there are testpoints you can use to check each ic with the next til you find the bad one.

[zomi]

Re: Sony 55hx823 4 Blinks

Pictures

[zomi]

Re: Sony 55hx823 4 Blinks

Voltage at the fail point on the ic is 2.848

At cn6002 i have 2.79v

[zomi]

Re: Sony 55hx823 4 Blinks

At the test points near the 4 clips for the ribbon cables I have 29.84 across each one

[zomi]

Re: Sony 55hx823 4 Blinks

I tried the method with Tcon disconnected
and power on and plug in to create white screen
All whiteness is uniform
no indication of led gone out.

When turning on today it was on and off intermittently

Now I have released the tension clip on 2 /4 of the led cables its been working for
20 mins
no issues..

If it works for min or 2 then turn off for few secs its back on for a min or 2..
@freakaftr8 i think that rules out cabling ??

So not sure at moment what issue is

[zomi]

Re: Sony 55hx823 4 Blinks

Now with the back off
And the heatshield off the led board

And the tension off on those 2 mentioned clips
been running now for

1hr 20

no issues

[zomi]

Re: Sony 55hx823 4 Blinks

Still going strong no issues

Stranged indeed...

[zomi]

Re: Sony 55hx823 4 Blinks

Ran for 5 hours then turned off

I decided to start touching the led driver...

thought maybe the cables...

Its up and runing again and no amount of putting pressure on the led cables will make it turn off...

really puzzling

[zomi]

Re: Sony 55hx823 4 Blinks

As you can see leds themselves seem to be fine..

[zomi]

Re: Sony 55hx823 4 Blinks

Had enough for today

Have took bl error signal to ground on the psu side..
Will see tommorrow if it brings any thing useful...