42" vizio/lg plasma sound no picture

[cadiman]

Re: 42" vizio/lg plasma sound no picture

I have checked that and all is good. I have a hand held temp scanner I use for automotive (brakes) and both of these boards y and z run at 145 degrees. I put a cooling fan on the y board, also I turned the voltage down a bit on the z board and that took care of the specles. On my pioneer the upper caps on both y and x drive are showing signs of heat stroke. (still waiting on the power supply) caps of any kind can`t take this kind of heat. The specs change rather quickly as temps rise. Also waveform adjustment does very little to picture quality. (vizio/lg) I really think these tvs need way more heat sink than they are given!

Going to look at a 40" and a 50" insignia both working with picture issues only about 2 years old...wish me luck!

Cadiman

[thelmores]

Re: 42" vizio/lg plasma sound no picture

Howdy all, am working on a vizio P42HDTV10A with an LG PDP42X32000 panel.

I have become somewhat familiar with checking the panel voltages, and if you are missing a correct voltage, remove power from the Zsus or Ysus boards to see if you can isolate which board is causing the voltage drop.

I "briefly" looked at a set today where the unit "clicks" when the unit is plugged in to AC, and clicks when the on switch is depressed. I have my Vs and Va voltages, and then then unit will shut down, presumably into a "protect mode".

Removing the power going to the Zsus and Ysus has no effect. Removing power from "both" these PCB's, the unit still goes into protect mode.

Could this be a problem with the Power supply itself?

Any advice on how to proceed would be greatly appreciated!

Best regards,
Mickey (thelmores)

[PlainBill]

Re: 42" vizio/lg plasma sound no picture

Howdy all, am working on a vizio P42HDTV10A with an LG PDP42X32000 panel.

I have become somewhat familiar with checking the panel voltages, and if you are missing a correct voltage, remove power from the Zsus or Ysus boards to see if you can isolate which board is causing the voltage drop.

I "briefly" looked at a set today where the unit "clicks" when the unit is plugged in to AC, and clicks when the on switch is depressed. I have my Vs and Va voltages, and then then unit will shut down, presumably into a "protect mode".

Removing the power going to the Zsus and Ysus has no effect. Removing power from "both" these PCB's, the unit still goes into protect mode.

Could this be a problem with the Power supply itself?

Any advice on how to proceed would be greatly appreciated!

Best regards,
Mickey (thelmores)

That's a problem either with the power supply itself, or one of the other output voltages. What I would do is try measuring each output voltage from the power supply and see if any of them are missing during the brief period the power supply is on. Troubleshoot from there.

PlainBill

[thelmores]

Re: 42" vizio/lg plasma sound no picture

Bill,

Thanks for the reply. Other than the Vs and Va, what other "output voltages" are you referring to?

As I stated before, I have my Vs and Va voltages, they are correct while the set is on.......

Did find this on LG's website....... it may be helpful to me, or others.....

If I follow this chart, it is suggests checking VSC and VY voltages. VSC is the Vscan voltage, found on the Ysus board, but what is -VY?????

Also notice the note about using the LED's on the control board for troubleshooting........ (don't do it!!!)

[thelmores]

Re: 42" vizio/lg plasma sound no picture

seemed to have answered my own question about what -VY is......... found this on LG's site.... this is not the same panel, but a similar one........

[PlainBill]

Re: 42" vizio/lg plasma sound no picture

If you look at the power supply you should notice a cable running to the main board. Usually there will be a label near the connector identifying which pins carry a number of important voltages - 3.3V, 5V, 12V, etc. Always check those voltages if the power supply appears to be misbehaving.

PlainBill

[thelmores]

Re: 42" vizio/lg plasma sound no picture

I have checked all the voltages on the panel, and they check good. Vs, Va, Vsc, -VY, +5, +12, +15, etc...... I can't find a bad voltage on the panel.

There is a switch on the power supply, "auto/normal". With the switch set in normal, the voltages come on for about 15-20 seconds, the cycle off. I assume this is "protect mode". If you place the switch in "auto", the power supply comes on as soon as power is applied, and the voltages do not go off at all.

Weird to see a panel where all the voltages are good, but still no video???

Control Card or Mainboard?

Thoughts anybody?

[PlainBill]

Re: 42" vizio/lg plasma sound no picture

I have checked all the voltages on the panel, and they check good. Vs, Va, Vsc, -VY, +5, +12, +15, etc...... I can't find a bad voltage on the panel.

There is a switch on the power supply, "auto/normal". With the switch set in normal, the voltages come on for about 15-20 seconds, the cycle off. I assume this is "protect mode". If you place the switch in "auto", the power supply comes on as soon as power is applied, and the voltages do not go off at all.

Weird to see a panel where all the voltages are good, but still no video???

Control Card or Mainboard?

Thoughts anybody?

I had this happen on a couple of TVs. The Z-sustain had failed - blown hybrid. All power supply voltages were good, the drive waveform on the buffer was good, and unless you knew what to look for, the output of the Z-sustain looked good. The significant symptom was a very faint picture in the lower right corner of the panel. It was easiest to see if I hooked up a signal source and stepped through the inputs until I heard the sound, then turned out the room lights.

PlainBill

[thelmores]

Re: 42" vizio/lg plasma sound no picture

Thanks Bill,

After all that, I quoted the customer to repair the unit, but he decided to buy an Insignia 42" plasma for $429......

These plasma sets are so cheap, and LG wants so much for parts, it makes it difficult.

And I have not been too impressed with Insignia thus far!

Anyway, thanks fort the help! Will try to contribute to the forum were I can!

[PlainBill]

Re: 42" vizio/lg plasma sound no picture

Thanks Bill,

After all that, I quoted the customer to repair the unit, but he decided to buy an Insignia 42" plasma for $429......

These plasma sets are so cheap, and LG wants so much for parts, it makes it difficult.

And I have not been too impressed with Insignia thus far!

Anyway, thanks fort the help! Will try to contribute to the forum were I can!

Interesting. Your customer bought Vizio - the throw-away TV line. When that failed, he is buying an Insignia - one of the few TV lines with less support than Vizio. When THAT fails is he going to buy a Dynex, or will he buy one built by Hong Kong Screen Door and Junk TV Company?

PlainBill

[smason]

Re: 42" vizio/lg plasma sound no picture

Interesting. Your customer bought Vizio - the throw-away TV line. When that failed, he is buying an Insignia - one of the few TV lines with less support than Vizio. When THAT fails is he going to buy a Dynex, or will he buy one built by Hong Kong Screen Door and Junk TV Company?

PlainBill

[retiredcaps]

Re: 42" vizio/lg plasma sound no picture

I have only seen Vizio at Costco Canada and wonder if Vizio's sales are due to Costco's generous return and warranty service?

Vizio dominates LCD TV market in U.S.

http://news.cnet.com/8301-13506_3-20035789-17.html

The company shipped nearly 2.9 million LCD TVs in the U.S. during the fourth quarter, capturing 27.6 percent market share, research firm iSuppli reported today.

The market researcher found that Vizio--which actually does not manufacture plasma TVs--still held onto the No. 1 position for the entire flat-panel TV market in the fourth quarter on the strength of its LCD TVs alone. Vizio's nearly 2.9 million LCD TV shipments gave it 23.9 percent of the entire flat-panel market in the U.S.

[zekev]

Re: 42" vizio/lg plasma sound no picture

I have a lg 42pc3dv it has sound but the picture only comes on in the bottom right corner i opened the back and saw there were like four caps that were blown on the center board I replaced those and still has the same problem.

[PlainBill]

Re: 42" vizio/lg plasma sound no picture

I have a lg 42pc3dv it has sound but the picture only comes on in the bottom right corner i opened the back and saw there were like four caps that were blown on the center board I replaced those and still has the same problem.

Classic symptoms of a classic problem with a simple solution. The Z-Sustain board is bad; probably the hybrid on it is shorted.

PlainBill

[fatboytp]

Re: 42" vizio/lg plasma sound no picture

I don't mean to pry but i have the same tv and boards. i have the same led's d15 not lit but i have a bad picture trying to figure out how to upload pics any help is very appreciated !! i have unplugged z-sus and y-sus tried to align can't get vs under 199v