Sony xbr-49x800e doesn't power on

[osh]

Hello!!

I have a Sony xbr-49x800e (just a couple of years old) that just would not power on anymore. The power LED does not light, nor does it appear that the backlight comes on either.

The power supply is producing 19.6v (even though it is listed as 19.5v).

The LED driver board has part # 1-981-457-14 on it.

I am hoping it's just a simple issue with the LED driver board and expect to start there, but I am hoping to get some direction. Where do I find a spec sheet to know how to even start testing it?

I first want to say I really don't know much about electronics, but am willing to try.

[dick_barton]

Re: Sony xbr-49x800e doesn't power on

Hello osh, If you can post photo's of your boards and give the connector voltages you have checked giving the pin number, its name and the voltage read is always a good starting point.

[nomoresonys]

Re: Sony xbr-49x800e doesn't power on

Maybe check those fuses on your LD1 Board, there's quite a few of them.

[nomoresonys]

Re: Sony xbr-49x800e doesn't power on

About 20 bucks, if it is the board or you could try troubleshooting it down to component:
https://www.ebay.com/sch/i.html?_fro...acat=0&_sop=15

[osh]

Re: Sony xbr-49x800e doesn't power on

Thanks everyone for the assistance!!!

@dick_barton - I'll attach the pic of the LD1 board here. I am not sure if this is kind of like a PC power supply in that it needs a signal to work? The two connectors that I can see are on the top and right side.

Top connector - pins 1-15 reading left to right while looking down at the connector. Pins 1, 2, 14, 15 are at 19.47v
All of the rest of the pins are at 0.0v

Right side connector (I am calling them) pins 1-15 on the top row reading left to right while looking at the connector. Then pins 16-30 on the bottom row reading left to right. (I hope I am using the standard terminology and numbering, please correct me if I'm wrong. I want to get it right.)
Pins 5 and 6 in the top row are at 19.61v (all others in this row are at 0.0v)
Pins 22 and 23 in the bottom row are at 19.61v
Pin 25 in the bottom row is at 0.11v
All others in the bottom row are at 0.0v
Pins 1, 3, 4, 8, 11, 12, 13, 16, 19, 26, 27 are all directly connected to ground.


@nomoresonys (I take it you're not a fan of Sony?) Any post that describes why? Other than this I've never had a problem...
What do the fuses look like? Like I mentioned, I'm not an electronics guru and when I think of fuses, I'm picturing little glass tubes with metal ends. I assume that testing is just a matter of checking continuity across the ends with power disconnected.

But I will say that troubleshooting to the component is not preferred. Like you mentioned, it's an inexpensive board and if it's not working correctly, will be replaced. But however I am open to troubleshooting to the component if only to increase my knowledge. Replacing SMT components is not in my skill set.

[dick_barton]

Re: Sony xbr-49x800e doesn't power on

I think the ones in the red circle are smd fuses.

[nomoresonys]

Re: Sony xbr-49x800e doesn't power on

Thanks everyone for the assistance!!!

@dick_barton - I'll attach the pic of the LD1 board here. I am not sure if this is kind of like a PC power supply in that it needs a signal to work? The two connectors that I can see are on the top and right side.

Top connector - pins 1-15 reading left to right while looking down at the connector. Pins 1, 2, 14, 15 are at 19.47v
All of the rest of the pins are at 0.0v

Right side connector (I am calling them) pins 1-15 on the top row reading left to right while looking at the connector. Then pins 16-30 on the bottom row reading left to right. (I hope I am using the standard terminology and numbering, please correct me if I'm wrong. I want to get it right.)
Pins 5 and 6 in the top row are at 19.61v (all others in this row are at 0.0v)
Pins 22 and 23 in the bottom row are at 19.61v
Pin 25 in the bottom row is at 0.11v
All others in the bottom row are at 0.0v
Pins 1, 3, 4, 8, 11, 12, 13, 16, 19, 26, 27 are all directly connected to ground.


@nomoresonys (I take it you're not a fan of Sony?) Any post that describes why? Other than this I've never had a problem...
What do the fuses look like? Like I mentioned, I'm not an electronics guru and when I think of fuses, I'm picturing little glass tubes with metal ends. I assume that testing is just a matter of checking continuity across the ends with power disconnected.

But I will say that troubleshooting to the component is not preferred. Like you mentioned, it's an inexpensive board and if it's not working correctly, will be replaced. But however I am open to troubleshooting to the component if only to increase my knowledge. Replacing SMT components is not in my skill set.

Indeed, that's good logic, yep test them for continuity, all the ones with the big F marked on the board.

[budm]

Re: Sony xbr-49x800e doesn't power on

Can we see the pictures of the whole backside of the TV showing all the board?
Do you red LED in the TOSLINK (Optical port) socket light up?

[osh]

Re: Sony xbr-49x800e doesn't power on

Once again, thank you all for the suggestions and direction.

Based on nomoresonys suggestions that big F's are fuses, and trying to follow the silk screening, I've got what I think are the fuses identified, and it's probably wrong, but here goes:
F2001 - good
F1002 - good

F1000 - open (bad?)
F1001 - open (bad?)
F2000 - open (bad?)
F2002 - missing(?)
F2003 - missing(?)

I am assuming they probably use the same board for various products and populate it differently depending on the product. That's why it appears some of the fuses are missing?

@budm - I am also attaching the full pic of the back side along with the main board and that board in the center on the bottom. It had a shield over it initially and when someone mentioned check the fuses on the LD1 board, I assumed that was it. When I didn't see any obvious fuses, I looked up LD1 and figured out that was the first board that I took a pic of earlier.

Also, I want to say that was an excellent suggestion. The TOSLINK LED is not on, which leads me to believe the main board isn't getting power.

Question - Could it be the main board? If LD1 is sending 19.61v to the main board, Is it waiting for the power on signal from either the remote or the manual switch on the right side? Then when it powers up, sends signal back to the LD1 to turn on and then I would see the rest of the voltages on those pins that are currently at zero?

[Davi.p]

Re: Sony xbr-49x800e doesn't power on

the fault is much probably at the main board, the fuses must be scratched a bit the terminals before test, the f1001 is the big black one indicated by arrow not the one circled in red.

[nomoresonys]

Re: Sony xbr-49x800e doesn't power on

Fuse is a fuse if it's blown it at least needs replaced and usually but not always, there's a fault somewhere that is blowing the fuse, sometimes it's just a random electrical spike/surge that will blow a fuse.

[osh]

Re: Sony xbr-49x800e doesn't power on

Hey guys,

Thanks for the help. I had to go out of town and will resume the troubleshooting when I return. I'll double check the fuses again, especially those that appeared to be open, and scratch the contact on each end a bit to make sure I'm making a good connection.

[budm]

Re: Sony xbr-49x800e doesn't power on

Recheck F2000, and F1000 again, since you may not be making good contact due to flux residues.
BTW, F1001 is the white fuse (the pointer is misleading) that is installed, F1002 is not installed. This PCB is made so you can install two fuses in parallel.
that black component to the left of F1001 looks to be TVS it has one end connected to the circuit ground plane.
Also look on the bottom side of the board to see if there are any fuse there too or not.

[R_J]

Re: Sony xbr-49x800e doesn't power on

On the board F2001 (4A/24V) and F2000 (4A/24V) seem to be identical circuits so if F2001 is good and F2000 is open, then check that circuit for a short. Also F1000 should be good and if it is open, the circuit around ic1000 should be checked.

[osh]

Re: Sony xbr-49x800e doesn't power on

(Ok, I made it back home and now looking at this again).

Thank you again for the pointers. I scraped the ends of the fuses that were tested bad previously (F2000 and F1000) and they all appear to be good. There are no fuses on the back side (related pic attached). And for confirmation, it sounds like F1002 is missing (the arrow pointing correctly at the parallel fuse). And F1001 is pointing incorrectly at a TVS (Transient-voltage-suppression diode - yeah, try searching "electronics TVS" and low and behold I see all kinds of ads for TVs... Ummm, nope, I wanna fix this one. :-) ) But F1001 is really that big white fuse sitting next to the empty parallel F1002 and it's good.

Next, I started looking at the main board. Someone mentioned that's most likely where the issue is and I'd like to (if possible) at least somehow confirm that. If possible with just a digital meter...
I found
F400 - good
F401 - good
F402 - good
F403 - good
F600 - good
F3201 - I can't tell, it looks like it's pointing at a cap, maybe the fuse is under that?

I also checked the back side and while it looks like there is an F2800, but that's not populated. I also pulled the heat sink off and I don't see any fuses under that.

Next steps? Power it on and start checking voltages again on the board?

[Davi.p]

Re: Sony xbr-49x800e doesn't power on

Must be control those few dc-dc regulators o this extra simple board, but i can't edit the photo, i'm out of home for sevveral days...

[R_J]

Re: Sony xbr-49x800e doesn't power on

It looks like F3201 is the black smd just above that elec. cap. Circled in Yellow. F2800 is not used.

[osh]

Re: Sony xbr-49x800e doesn't power on

@R_J

(I think that image is for someone else? The back side of this main board doesn't look like yours.)

But you are correct, there is an smd fuse between the two caps. It tests out ok.

If fuses all appear to test out ok, I am assuming I need to start checking voltages across certain points?

[R_J]

Re: Sony xbr-49x800e doesn't power on

You are correct, I uploaded the wrong picture, time to clean off the desktop.
Is this the GN3TR Chassis?

[osh]

Re: Sony xbr-49x800e doesn't power on

(maybe?) it's a 49FRE chassis? These are the only two labels that are on the chassis.