LG 60PY3DF shuts off

[brentkhack]

Re: LG 60PY3DF shuts off

I just checked and it showed 0, but I turned the tv on and then shuts off and then it showed 3 when off.

[tom66]

Re: LG 60PY3DF shuts off

So it fell to zero rapidly? Is it possible to wedge the probe in the connector so you can see how the voltage is varying? If it drops low, then turns off, it is a problem with the undervoltage protect, but if it suddenly shuts off then the power supply is actually switching off for some reason.

[brentkhack]

Re: LG 60PY3DF shuts off

Hooked everything up like u said. I turned power on and I got 189. Just before the click from sub PSU on right of tv which when the screen turns off, the reading went down almost instantly to 4.

[tom66]

Re: LG 60PY3DF shuts off

So this indicates the TV is shutting down for some reason, but it's not an under voltage protection problem.

Are there any labels near these connectors on the power supply? If so, is there a pin marked AC-DETECT or ACD?

[brentkhack]

Re: LG 60PY3DF shuts off

So this indicates the TV is shutting down for some reason, but it's not an under voltage protection problem.

Are there any labels near these connectors on the power supply? If so, is there a pin marked AC-DETECT or ACD?

I didn't see ACD, but did see AC-ON on the sub PSU below the main PSU.

[tom66]

Re: LG 60PY3DF shuts off

That's probably it - can you check that pin:

- in standby
- before it shuts off
- after it shuts off

If it is good, it should measure 5V all the time, I think.

[brentkhack]

Re: LG 60PY3DF shuts off

That's probably it - can you check that pin:

- in standby
- before it shuts off
- after it shuts off

If it is good, it should measure 5V all the time, I think.

If I touch the pin that is connected to the board when it is disconnected I get 4.31 I can't check the volts during startup because the power light doesn't come on. Now when I check with everything connected, I get 3.74 during startup and when it shuts off it goes up a bit to 3.76

[tom66]

Re: LG 60PY3DF shuts off

If I touch the pin that is connected to the board when it is disconnected I get 4.31 I can't check the volts during startup because the power light doesn't come on. Now when I check with everything connected, I get 3.74 during startup and when it shuts off it goes up a bit to 3.76

Does it not do the original symptom of powering up with a picture and then shutting down? 3.74 seems quite low, and it could be causing an issue. I can think of one way to fix it temporarily, but it will require a 220 ohm resistor. It is a permanent fix if you don't mind the speakers "crackling" when it shuts down, as the AC detect's purpose is to mute the speakers on shut down to stop random sounds getting out when power fails (like older tube TVs used to flash when you turned them off.)

[brentkhack]

Re: LG 60PY3DF shuts off

Does it not do the original symptom of powering up with a picture and then shutting down? 3.74 seems quite low, and it could be causing an issue. I can think of one way to fix it temporarily, but it will require a 220 ohm resistor. It is a permanent fix if you don't mind the speakers "crackling" when it shuts down, as the AC detect's purpose is to mute the speakers on shut down to stop random sounds getting out when power fails (like older tube TVs used to flash when you turned them off.)

Yes, the tv did the normal boot then shut off during testing. Please let me know how you would fix this. I don't care about the crackling, as long as we can use this thing.

[tom66]

Re: LG 60PY3DF shuts off

I used the same fix on the 42PC1D. It seems endemic to LG plasmas, several other users have had the same issue, although I've only so far seen it on the 42" and on the LG 50PS3000, though the user never got back to me on that one so I don't know if it fixed it for his one. But it's worth a shot.

On that same connector, or a nearby one, there should be a pin marked 5V Standby or 5VS or 5VSTBY.

Connect the 220 ohm resistor from 5VSTBY to AC-ON; for now, you can wedge it in the connector pins, a more permanent solution would be to solder it on the underside, but this is just a test. Check that the AC detect is now about 5V, and see if the TV still has the problem.

[brentkhack]

Re: LG 60PY3DF shuts off

Yes, it is listed as STBY5V on the same connector. So which one of these would you recommend to use since there are some differences http://www.frys.com/search?search_ty...resistor&cat=0

[tom66]

Re: LG 60PY3DF shuts off

http://www.frys.com/product/997726?s...H:MAIN_RSLT_PG

looks okay to me

95 cents is quite a lot for a single resistor. I just bought a pack of 100 qty 220 ohm resistors for 51 pence.

An electronics stockist would list them as a "220 ohm 1/4W 5% carbon film resistor". These are very common components, most stores will stock them (even useless RadioShack.)

I'm still not 100% on whether this is your problem because the voltage seems low, but on mine it actually dropped to zero just before it shut down. However, it could be that the problem is developing slowly and it has now reached the point of failure. Did you set ever give problems before it finally started shutting down just after turn on? Lasting less and less time each time, shutting down randomly occasionally?

[brentkhack]

Re: LG 60PY3DF shuts off

A person at work gave me this and yes, he did say it would shut down after a few hours, then got worse and worse. The first repair shop told them to take the back panel off to "fix" it. Then they had a second tv repair shop look at it and they said it was the PSU. The tv shop then told him with this tv you can replace that then something else will fail and failing parts might never stop, so they bought a new tv. On my way to the store now.

[tom66]

Re: LG 60PY3DF shuts off

I wish someone gave me a faulty 60" plasma, though I don't know where I'd put it...

Sounds like a typical useless TV repair shop to me, no component level repair, just "replace the board". Give the 220 ohm resistor a go, then report back. By the way 220 ohms is not crucial. It can't be zero because it could damage whatever controls the AC detect (too much current), but anywhere from 150 ohms to 330 ohms is probably fine, if that makes finding components a little easier.

[brentkhack]

Re: LG 60PY3DF shuts off

I actually see two STBY5V and tried them both with the blue AC ON and still the same power up, then shut down using the 220 ohm resistor.

[tom66]

Re: LG 60PY3DF shuts off

I hoped that would fix it.

Okay, is there a pin for VSON?

Does STBY5V vary when it shuts down? (Does the power LED change?)

[brentkhack]

Re: LG 60PY3DF shuts off

I hoped that would fix it.

Okay, is there a pin for VSON?

Does STBY5V vary when it shuts down? (Does the power LED change?)

There is a VS-ON on the same plug as STBY5V. It shuts down the same way and you owe me 95 cents, j/k.

[tom66]

Re: LG 60PY3DF shuts off

Yeah, so the main board is switching it off for some reason. My 42PC1D did the same thing but it was doing it because of AC-D going low. How is STBY5V? What about the 3.4V output, if it has one...

Edit: I didn't consider the possibility that 220 ohms is not capable of overriding the AC detect. What does AC detect measure at with the resistor in place? Does the TV make a crackling/popping sound from speakers now when it is unplugged?

[brentkhack]

Re: LG 60PY3DF shuts off

VS-ON is 1.64 in standby and then 3.9 when turning on. Both 5VSYS are 5.02v at standby and then 4.98 during startup.

[brentkhack]

Re: LG 60PY3DF shuts off

Yeah, so the main board is switching it off for some reason. My 42PC1D did the same thing but it was doing it because of AC-D going low. How is STBY5V? What about the 3.4V output, if it has one...

Edit: I didn't consider the possibility that 220 ohms is not capable of overriding the AC detect. What does AC detect measure at with the resistor in place? Does the TV make a crackling/popping sound from speakers now when it is unplugged?

I have heard the popping before, but usually it is a quick buzz sound.