Sony KDL-46S504 - Replaced Power Supply, No Picture

[gce]

So, a couple weeks ago I picked up a Sony KDL-46S504 that was the victim of a power surge. According to the previous owners, the screen flashed white during a lightning storm and then they were unable to turn the TV back on.

I'm new to electronics repair in general but I did a little research and figured out that replacing the power supply might be worth a shot. Well, now I have the new power supply installed. When I press the "power" button, I hear a click from the power supply and the front green led indicator turns on. However, that's it. I get no picture and none of the other buttons on the TV do anything.

So, Badcaps, what do you suggest that I do next? Should I keep on keepin' on or am I just throwing good money after bad?

[PlainBill]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

So, a couple weeks ago I picked up a Sony KDL-46S504 that was the victim of a power surge. According to the previous owners, the screen flashed white during a lightning storm and then they were unable to turn the TV back on.

I'm new to electronics repair in general but I did a little research and figured out that replacing the power supply might be worth a shot. Well, now I have the new power supply installed. When I press the "power" button, I hear a click from the power supply and the front green led indicator turns on. However, that's it. I get no picture and none of the other buttons on the TV do anything.

So, Badcaps, what do you suggest that I do next? Should I keep on keepin' on or am I just throwing good money after bad?

Well, it's your money. The main board is available on eBay for under $70 from several sellers.

PlainBill

[gce]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

Well, it's your money. The main board is available on eBay for under $70 from several sellers.

PlainBill

Is the Main Board the next logical step in board to replace? Is there any testing that I should do first?

[tom66]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

What was the problem before the power supply was replaced?

[gce]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

What was the problem before the power supply was replaced?

No power at all. No response to the "power" button and no green led indicator. This happened following a power surge.

[PlainBill]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

Is the Main Board the next logical step in board to replace? Is there any testing that I should do first?

Well, you can hook up a signal source (DVD player, game console, etc) and see if you can step through the inputs until you hear the audio signal. You can check the LDO regulators on the main board. The Service Manual might be available from Elektrotanya, that might provide other insights.

Frankly, repairing anything that has taken a power surge is a crapshoot. After replacing the main board you might have to repair or replace the inverter, or find the tcon is bad.

One thing that prevents this from becoming a totally bottomless money pit is that you should be able to sell any boards you buy at a reasonable fraction of what you paid for it.

PlainBill

[gce]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

One more thing, I also noticed a slight buzzing coming from both the speakers and the top-center board on the tv (I'm not sure which board this is, it still has a metal panel covering it).

[gce]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

New Main Board ordered. I'll update the thread once I install it.

[PlainBill]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

One more thing, I also noticed a slight buzzing coming from both the speakers and the top-center board on the tv (I'm not sure which board this is, it still has a metal panel covering it).

That's the tcon.

PlainBill

[Village Electronics]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

Posted in error

[Village Electronics]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

posted in error

[gce]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

I also just looked at the back of the main board and noticed that there was some light browning in a few spots. Is this normal at all or evidence of scorching? I have to run to work but I'll post pictures later.

[tom66]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

I also just looked at the back of the main board and noticed that there was some light browning in a few spots. Is this normal at all or evidence of scorching? I have to run to work but I'll post pictures later.

Brown marks are just signs that parts have got hot around that area. If well designed, electronic components can get hot without issue. But it is something to look out for.

[rmoody]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

So, a couple weeks ago I picked up a Sony KDL-46S504 that was the victim of a power surge. According to the previous owners, the screen flashed white during a lightning storm and then they were unable to turn the TV back on.

I'm new to electronics repair in general but I did a little research and figured out that replacing the power supply might be worth a shot. Well, now I have the new power supply installed. When I press the "power" button, I hear a click from the power supply and the front green led indicator turns on. However, that's it. I get no picture and none of the other buttons on the TV do anything.

So, Badcaps, what do you suggest that I do next? Should I keep on keepin' on or am I just throwing good money after bad?

you say no picture? What about the backlights? are they on?

[gce]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

nope, no backlights that i can see.

[westom]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

No power at all. No response to the "power" button and no green led indicator. This happened following a power surge.

Appreciate how a surge does damage. A surge does not enter on AC mains, destroy a power supply, and stop. A surge must first have the same current flowing everywhere, simultaneously, in a path from the surge source (ie cloud) to earth. If current entered on AC mains, then some other path must be the outgoing to earth.

A typical path is outgoing via the cable TV coax. Because all cable TV wires are required to be earthed before entering the building. Therefore the front end (signal) circuits could be damaged. Or it could find earth via an external speaker. Arc from the speaker wire to a nearby air duct.

To better understand damage means locating both an incoming and outgoing electric current path. Damage will be in one or some parts in that path.

[gce]

Re: Sony KDL-46S504 - Replaced Power Supply, No Picture

"new" main board fixed it! to make it even better, the ebayer that i bought the board from made a shipping error. he ended up rectifying it and just giving the board to me for free. so i ended up getting a 46" tv for about $60 in parts! thanks to everyone for their advice.