Vizio P42HDTV10a power no screen

[Fuyukazehime]

Hi, I'm new here! I've looked around but can't find my specific problem anywhere. It's possible I missed it so I'm sorry to make another thread but here it goes!

My Vizio 42in plasma gets power but no screen. When plugged in the amber standby light is on. When I press power the light turns green and I hear the sound of a TV turning on, there's a click and a slight buzz then nothing. The light remains green but there is no display or any indication of any power other than the green power light. I need help on where to go from here.

[capkid]

Re: Vizio P42HDTV10a power no screen

This plasma appears to have LG components, which could point to a bad IPM on the YSus or the ZSus; a very common issue. Do you have audio? You may have to blindly change inputs to find an input that produces audio.

[Fuyukazehime]

Re: Vizio P42HDTV10a power no screen

No sound at all. No picture or sound. TV turns on, sounds like it's trying to then nothing.

[capkid]

Re: Vizio P42HDTV10a power no screen

OK, you'll have to pull the back cover off and take some voltage measurements. Do you have a digital multimeter?

[Fuyukazehime]

Re: Vizio P42HDTV10a power no screen

Yes, I've already measured some of the voltages. What should I be looking for?

[capkid]

Re: Vizio P42HDTV10a power no screen

Power supply output voltages are a good place to start. These include the VS and VA panel voltages. Please post your results.

[Fuyukazehime]

Re: Vizio P42HDTV10a power no screen

I checked all the power outputs from the power board at 222mv with the TV powered and on. When i first plug in the TV and power it on, i get 20V on the VS but that's only for a moment. It will click then buzz a little then nothing. During the buzz i get the 20V, after that i get 222mv. This is with the connectors attached.

[MagicSmoke]

Re: Vizio P42HDTV10a power no screen

Unplug all power wires from PSU to X & Y boards, leave all others plugged in. Try to turn on and see if VS will stay on at listed volts on panel sticker. If it does then plug X board in and turn on to see if it stays on.

If it stays on X should be good, do the same for Y.


Without Pics of your setup it will be difficult to help you diagnose.

[Fuyukazehime]

Re: Vizio P42HDTV10a power no screen

I got a picture without the right board plugged in, i believe it's the Z-sus board. Screen came on and said GNAL in the middle.

[capkid]

Re: Vizio P42HDTV10a power no screen

Are the ceramic fuses on the ZSus blown?

[Fuyukazehime]

Re: Vizio P42HDTV10a power no screen

All of the fuses are intact. I did continuity tests on all fuses.

[capkid]

Re: Vizio P42HDTV10a power no screen

Can you post pics of the TV's picture?

[Fuyukazehime]

Re: Vizio P42HDTV10a power no screen

Here are several pictures. I hope these help! The longer I leave the TV on the more Red lines appear!

[MagicSmoke]

Re: Vizio P42HDTV10a power no screen

So it will stay on with X board disconnected. Something is wrong with X or buffers. If reconnected it will not show a picture?

Looks like an IPM might be bad. Take X out and check the power pins to ground to see if it's shorted.

[Fuyukazehime]

Re: Vizio P42HDTV10a power no screen

I'm told that's the Zsus but yes it turns on and stay on with the board disconnected. Reconnect the board and nothing, it tries to turn on then some sort of failsafe kicks in and nothing.

[capkid]

Re: Vizio P42HDTV10a power no screen

Yes, the board on the right is the ZSus. "X" or "X-main" is the equivalent in Samsung plasma TVs. Some people use the terms interchangeably, which can be confusing, since there are horizontal X-buffer boards in LG plasmas.

On the ZSus, you can check for shorts to ground on the IPM. Example: http://blog.coppelltvrepair.com/2011...m-for.html?m=1

[Fuyukazehime]

Re: Vizio P42HDTV10a power no screen

Ok, I couldn't figure out how to take the heatsink off. Tomorrow I will desolder the whole IC and test that way but i tested it on the board from the backside and got the following results:
VS - GND is open
VS - SUS_OUT is open
VS - ER_UP_OUT and ER_DN_OUT are both open
GND - SUS_OUT is shorted
GND - ER_DN_OUT and ER_UP_OUT both shorted.
SUS_OUT - ER_DN_OUT and ER_UP_OUT are both shorted

[capkid]

Re: Vizio P42HDTV10a power no screen

Ok, I couldn't figure out how to take the heatsink off. Tomorrow I will desolder the whole IC and test that way but i tested it on the board from the backside and got the following results:
VS - GND is open
VS - SUS_OUT is open
VS - ER_UP_OUT and ER_DN_OUT are both open
GND - SUS_OUT is shorted
GND - ER_DN_OUT and ER_UP_OUT both shorted.
SUS_OUT - ER_DN_OUT and ER_UP_OUT are both shorted

Be careful removing the IC if you don't have a desoldering gun. In any case, I'd add a little fresh solder to the pins first.

[Fuyukazehime]

Re: Vizio P42HDTV10a power no screen

Can't figure out how to get the darn thing off without a desoldering gun lol. I can't find my copper mesh stuff that takes the solder off =( My heat gun gets the solder soft but i still cant seem to get the darn thing to move!

[capkid]

Re: Vizio P42HDTV10a power no screen

You can't remove it without sucking up the solder - too many pins to heat. Also, the solder is bonded to the front side of the board.