TC-P58S2 completely dead after power surge

[DLinkOZ]

I've read the other threads about this TV, but my situation is a bit different. There was a power surge, and afterwards there are no signs of life in the TV. AC going into the power supplies is good. Hit the power button, nothing. Same with power button on remote. The diagnostic LEDs on the main power supply do nothing. All six fuses are good (3 on each board).

I realize that the power button runs through the main board, so I'm hoping to get a little direction as to where to begin troubleshooting.

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

Spot checking diodes on the power supplies yields odd results. Some show very low one way, nothing the other (as one would expect). Most show ~500 ohms one direction, ~1800 the other direction. Some are 500-800 ohms in both directions.

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

And I found a 4th fuse on the main power supply board, also reads good.

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

I do have 5v standby going out of the primary power supply to the mainboard. So it's looking like the main board isn't triggering the power on. Any way to verify that, or troubleshoot that board to a potential component failure?

*EDIT*
To clarify - I get 4.99v out of P7 on the white wire. I get nothing on the white wire on P6. Does anyone know if this is proper, still pointing to the mainboard?

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

So I believe I can definitely nail it down to the mainboard. The 5v standby is present on P7 pin 1, going to the mainboard. A regulator knocks it down to 3.3v, which the CPU sends back to the power supply via P7 pin 5 to initiate a power on. When I press the power button, I see nothing coming back via P7 pin 5.

So can anyone say if I'm off base, or does that seem like a logical conclusion? Whether it be the IC8001 that fried, the power regulator, or whatever, something died on the mainboard?

Though I'm also not getting the 3.3v from the mainboard to the IR and power button board (connector A1, pin 3). So possibly it blew the power regulator that takes the standby voltage and sends to the various parts of the mainboard). Not sure if that's something that can be repaired/diagnosed individually and if it's worth the hassle. But with the cost of the board itself, I'm game to try!

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

I have some emails out to companies offering repairs, but looking for recommendations - does anyone know of a good place to get a replacement main board (AE suffix) or have this one repaired? They're not terribly common in the normal places (ebay, etc) and most of the normal parts sites don't stock it.

[ivoh]

Re: TC-P58S2 completely dead after power surge

check the regulators you find around the mainboard for output and input. make sure they are putting out the right voltage too. look around on the main board for smd fuses. or smd resistors with a 0 or 000 on them (ive seen those go bad.) trace the standby voltage on the main board and see how far it gets. with a little soldering skills it shouldnt be impossible to replace smd components (regulator,resistor, etc.) just hope the cpu isnt fried!

[Glitcher]

Re: TC-P58S2 completely dead after power surge

I just posted about a TCP50C2 with the exact same problem, but I've never seen these "power surge" problems ever being repaired without swapping out the main board.

More than likely I'd say the main processor is fried... Or at least the HDMI processor. If youre lucky enough you would have to remove the hdmi processor and it'll remove the short to the main processor and allow the tv to signal on. (Its just a theory though.) I wouldn't recommend doing it though.

I had a vizio, which I did that and allowed the set to turn on however it was still bricked so I concluded the surge went through the main cpu as well.

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

There's a test point for the 3.3v, and I obviously get nothing there. But I do only get 550 ohms between it and chassis ground, so that seems awfully low. Long of it is I'll probably need to replace the entire board, but so they're so few and far between that I'll likely hold off until a good deal comes along. So in the meantime, I'm good with experimenting in that .00001% chance of it being something relatively easy.

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

Just for giggles, there's a v5803 just below the connectors from the PS that I'll probe around on. But that would be entirely too easy.

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

It's something else, not sure what's in-circuit between the connector from the PS and the various regulators, but none of them are seeing anything on the vin leg (I would expect to see the 5v that it uses to drop to 3.3v for output).

[martino]

Re: TC-P58S2 completely dead after power surge

What's the numbers on the mainboard? I can check my parts shelve to see if I have one.

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

TNPH0831, suffix AE.

[Glitcher]

Re: TC-P58S2 completely dead after power surge

Oo that's the one I need also! TNPH0831 suffix AV though

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

Yeah, they're not very common. I think I saw an AV on eBay. There's an AE on there, but at $190 I'll sit it out and wait for something else to come along!

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

Yeah, your AV on eBay is $150. I did find a repair service for my AE at $112, so I have a question in for them since their description didn't give me confidence (lots of "if we can" and whatnot).

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

Has anyone seen a schematic for these boards? I'd love to see where the 5v is failing, since it's not present as early as the regulator that knocks it down to 3.3v (literally half an inch from the connector). I also get the same 550 ohms between the vin pin on that regulator and ground, just like I do on the 3.3v test point. So something's out of whack there.

[tw2005]

Re: TC-P58S2 completely dead after power surge

For the sake of fault finding, I would download any manual for a S2 series TV. The mainboards are effectively identical with different firmware loaded.

U2 series also have a TNPH0831 and are FHD

C2 series,too but are only 720p , will differ a lot more in cct, so I'd avoid them.

Here's a 54" model



That should get you the schematic of the TNPH0831 for the FHD models.

You may already have the troubleshooting guide.




From what I see, if you have 5V at A7, pin1, IC4700 at pin7 should also have 5V, IC9004 also should have 5V at pin 25. Both are marked as producing 3.3V from the 5V.

Do you have an identifier for the 3.3V reg that is only 1/2 inch from the A7 connector? i can't see one not that I'm saying you're necessarily wrong.

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

I had the troubleshooting document, but that first PDF is great. I'll pour through it, see if something hits me while waiting for a reasonable replacement part. Thanks!

[DLinkOZ]

Re: TC-P58S2 completely dead after power surge

Just to follow up on this - I'm pretty sure that at least it had a bad regulator somewhere, but I didn't want to fix that only to find more things gone (since it was a power surge). So a replacement mainboard fixed it right up. Thanks to everyone for the input!