Need help figuring out whats wrong with my LG 50PJ350

[joyride]

Need help figuring out whats wrong with my LG 50PJ350 - UB
This TV was manufactured in december 2010 and is a 50 in. plasma

Information:
So I was watching tv one day for maybe 4-5 hours ,and everything was fine. Turned it off and ate dinner.

Then later that night when I turned it on,all the TV did was power on for about a second then turn off on its own before the picture would show.The screen would flash for a split second,but barely.

I took off the back and dusted it with compressed air , and still the same result

Ill post some pictures of the back,dont know if that will help any.

Any advice will be MUCH appreciated

[tom66]

Re: Need help figuring out whats wrong with my LG 50PJ350

Do you have a digital multimeter (DMM)?

[mu2]

Re: Need help figuring out whats wrong with my LG 50PJ350

A common problem with this model is that one or both of the 22 ohm 5 watt resistors fail. These are the white upright resistors in the upper right side of the power supply board.
Sometimes other parts fail in addition to these and kits are available on ebay.
I have fixed two similar models (LG 50PK550UD) but the symptom was a little different. The relay on the power board would just click and try to start.
They are available from Digikey - part number A102460-ND.
You will need a meter to determine if they are bad.
There may both other parts that have failed as well as the resistors.
Good luck.

Mike

[joyride]

Re: Need help figuring out whats wrong with my LG 50PJ350

Yes I do.Im not very experienced using it though.I took a two month class in basic electronics work and am rusty on that material...

What should I check?Dumb it down too

[joyride]

Re: Need help figuring out whats wrong with my LG 50PJ350

Ok thanks for the advice mu...

Tom do you agree with what he said,is there any other common problems or possible things you can think of from what i told you happened.

[tom66]

Re: Need help figuring out whats wrong with my LG 50PJ350

I have heard of that problem. Pull out the power board, and check the resistance of those components.

[joyride]

Re: Need help figuring out whats wrong with my LG 50PJ350

Ok so I found the resistors you are talking about.But im forgetting actually where to put the probes at to measure each resistor's resistance.

Heres a picture with color coded arrows..please point out which arrows i should put each probe on for each of the two resistors.

Thank you!

[tom66]

Re: Need help figuring out whats wrong with my LG 50PJ350

You'll need to flip the board and test under the board. Each resistor has two terminals.

[joyride]

Re: Need help figuring out whats wrong with my LG 50PJ350

Hmm ok,well im assuming the 2 pointed metal tips on the back of the panel directly behind each resistor were the terminals you mentioned?

Well I put my probes to each set of "terminals" and all it did was flash random numbers,it didnt stay on one number....Maybe i had the wrong settings?

I had my DMM set to AC and 200 OHM...

Thanks for the help

EDIT: thought I would throw in that when i had the setting at 200 OHMs the reading stayed at 1 for both resistors.
When I then changed the setting to a higher number like 200k ohms or more it would flash from 1 to random higher numbers.

[Mt.Man]

Re: Need help figuring out whats wrong with my LG 50PJ350

Most of the times one resistor opens (more than 22 ohms). If one is bad change both resistors out.

[joyride]

Re: Need help figuring out whats wrong with my LG 50PJ350

Im still confused about what happened,can someone answer my last question?Ty

[tom66]

Re: Need help figuring out whats wrong with my LG 50PJ350

It's just because the resistors are in circuit, something is interfering with your meter, but both are bad and need replacing.

[joyride]

Re: Need help figuring out whats wrong with my LG 50PJ350

Can you please go into more detail with that?Are you assuming the resistors are bad or you can tell by what my meter read(considering you said something is interfereing with my meter that makes it sound like my meter was just messed up)?Like I said im not sure I had it on the right settings,was I using the right setting?

Thank you

[tom66]

Re: Need help figuring out whats wrong with my LG 50PJ350

No, your meter is fine. Essentially -- you aren't measuring just that resistor. You're measuring the rest of the circuit -- what's connected to it -- as well.

[joyride]

Re: Need help figuring out whats wrong with my LG 50PJ350

So how do you know the resistors are broken from what I told you?

Thank you

[tom66]

Re: Need help figuring out whats wrong with my LG 50PJ350

Yes, they appear to be failed.

[Th3_uN1Qu3]

Re: Need help figuring out whats wrong with my LG 50PJ350

So how do you know the resistors are broken from what I told you?

Thank you

Since the resistors are 22 ohms, your meter should have read 22.0 (or at least something close) on the 200 ohm scale. Since it reads 1 on the left (over range), it means the resistors are somewhere much higher than 22 ohms, so they are bad.

[joyride]

Re: Need help figuring out whats wrong with my LG 50PJ350

Ok thanks,is there any other parts that I should check before i start to order parts?(considering what i told you the tv does when i turn it on, or any damage the resistors themselves may have caused by breaking)

[joyride]

Re: Need help figuring out whats wrong with my LG 50PJ350

Also,in addition to my last question, just to make sure,the TV is suppose to be unplugged and off when i test the resistors right?

[tom66]

Re: Need help figuring out whats wrong with my LG 50PJ350

Yes.
It appears to be a common fault, perhaps due to poor design or a manufacturing defect.