Sony KDL46HX800 Sometimes wont power on 3 blinks

[jumpinjohn]

Hi,

My TV works greet, but recently has developed an intermittent problem. When I go to turn on, light goes from red to green, hear a click, then lights red, 3 blinks.

I've tried resetting when it has the problem doesn't help. If I unplug and wait awhile, most of the time will do the same, but after about 20 tries (and a few days of praying/cussing), it will fire back up normally showing the Sony logo and the red button staying on. When this happens TV comes on as usual.

So now, when I get it on, I just leave it on.

I suspect bad caps. But I have looked at the board twice, and see no signs of any bad caps. (no bulging or leaking). I have read that they can go bad without showing, or I guess they may be getting ready to bulge.

I read through 18 pages of Sony issues here, and don't see any similar problems. I have limited electronics experience. Have a cheap multi-meter, and have fixed a couple of TVs and monitors by replacing caps. I've planned on ordering all the caps and replacing them.

What do you guys think?

I'm attaching some photos.

[Glitcher]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

I doubt the caps are at fault if they don't seem bulged at all. In small cases it is possible they may be bad but its more likely their not and sometimes its just a waste of time to check them all and find out theyre all good (which is always usually what happens).

If its intermittent it could be a cold solder joint somewhere? Even on the main board.

[tom66]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

3 blinks: DC_ALERT, DTT Error or Audio Fault.

[jumpinjohn]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

I guess that is possible.

I should add that the TV has been working fine for a couple years and hasn't been moved. Also the problem isn't really that intermittent. Seems about out of the last 6 times it has been turned off, it has only turned right back on once.

[tom66]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

I would suggest a thermal issue: something is temperature intermittent.

Try waiting a day then seeing if from cold the TV will turn on. If not, get a hairdryer or other heating appliance and heat up parts of the TV. Then see if it turns on.

[jumpinjohn]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

Thanks Tom. Yes I found that, but not sure what it means.

[jumpinjohn]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

Actually I did try heating though the back vents with a hair dryer the first time it occurred.
I hadn't had the back off. It didnt help.

I am in S Florida, and it has been a little cold (cool) 50-60 when these problems started.

I'm really hesitant to turn the tv off right now. Went a few days without it this week, and the lady says not to mess with it till weekend is over.

I'll give it a shot next week. Is there any certain areas, I should focus the heat on when I try it?

[tom66]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

Focus on the power board and the main board for now.

[Mt.Man]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

3x error most likely the BAL Main board. A-1778-906-A

[jumpinjohn]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

I've been goggling all over the place today with so many different answers. I just came across this site.
http://maudioelectronickeyboard.dani...-sony-d-board/

Is the D board the same as the BAL Main?

[jamesb6]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

I have a similar problem with my KDL40EX620. As soon as you plug it in it flashed the red LED 3 times, pauses and repeats. I have tried the Sony chat line and that was about worthless. I assume it is the Power Supply or Main Board, but I want to replace the most likely board first. Any suggestions out there?

Thanks

[jamesb6]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

BTW...the fuse on the Power Supply is good and the 3 tiny fuses on the main board are good as well.

[jumpinjohn]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

I haven't found a clear answer on this one yet James. I'm hesitant to turn my off right now. I think I am going to order and try replacing the caps first since that would be the cheapest fix. I know it may unlikely be the culprit, but I have read that they can go bad without showing. And since you can't check them without removing them; I am going to order some and have them here, but I am going to try the hair blower trick too next time I open it up.


BTW is it cold where you are?

[jamesb6]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

Yeah. I am suspicious of the Power Supply. I think I am going to put the Fluke meter on them tonight and take some measurements tonight. I am not sure about caps on mine. Sony typically uses decent caps and in my case, the 3 flash condition starts when it pis plugged in. I'll keep you posted. I just wish I could find a document describing what the 3 flashes actually means. Sony must be holding a gun on everyone and not allowing service documents out on the web.

Supposed to get to 50 degrees today....was cold over the weekend and had 3 or 4 inches of new snow when I got up on Saturday. Palm City sounds warm.

[jumpinjohn]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

Keep me posted. I just asked about he cold since it was the coldest it has been here in awhile when this acted up. Now that it's past I am hoping the TV fixes itself (at least to next winter, lol)
Yea I thought for sure I could hunt down something more definite about the 3 flashes. I did come across what tom posted above somewhere.

[jamesb6]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

Ok John. I did some testing tonight and here is what I found on my KDL40EX620. The power supply is supplying 3.3vDC to the Main Board. When I press the power button the Main Board sends the 3.3vDC back to the Power Supply to turn it on. 3.3vDC is returned to the Power supply for about 2 seconds and then it turns back off. I measure for 12vDC coming out of the Power Supply and there is not anything coming out....not even briefly when the Power Supply is being told to turn on by the Main Board.

I believe that i likely have a bad power supply...will not trun on 12vDC for whatever reason.

Does anyone have any thoughts....is my reasoning sound....am I missing anything?

[budm]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

Service manual:
http://elektrotanya.com/?q=showresul...oria=&kat2=all

Are you reading that 3.3v at the power on pin of the power supply board, that signal is generated by the main board to turn on the power supply.

[jamesb6]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

Actually I see 3.3v coming from the power supply constantly. I also see 3.3v at the power supply coming from the main when I press the power button, but only for about 2 seconds, then it drops to 0v. When I press the power button and look at the 12v output of the power supply, there is 0v.

[jamesb6]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

Interestingly though, when I plug the set into the wall outlet, it starts its 3 blink right away, not after I attempt to turn it on

[budm]

Re: Sony KDL46HX800 Sometimes wont power on 3 blinks

The power supply has the 3.3v standby power supply which is always running the minute you plug the TV into the outlet, this 3.3v is used for running the processor. When the processor receives the power on command from the remote or from the power switch, the main board will send the HI (>3) signal (POWER PIN) to turn on the rest of the power supply section to run the TV.
So some how the main thinks there is problem, so it goes into shutdown mode. Need to look at the service manual for more info.
I am downloading the service manual, you should also do the same.