Dead LG 50PS80ED

[gunnahafta]

Hi all, i have a LG 50inch Full HD Plasma model 50PS80ED. For 2 years it worked great until this morning when i turned it on. I power it on and you hear the usual click, the white light across the bottom comes on but the 3 or 4 seconds later it goes into what appears to be standby mode. I try to wake it up from standby and the same thing happens, the white light coems on but them back to standby a few seconds later. No picture or sound.

Ive read a few threads and there has been a number of suggestions about checking cap's aloing with many pictures for reference. To my best observations they all look ok to me. Cant see any obvious blackening etc to indicate a burnt out component. Can any one suggest thigns to do to test different things like pulling a particular cable to see if its power supploy or something else etc. Any help would be great.

[PlainBill]

Re: Dead LG 50PS80ED

Since you didn't help us by supplying pictures, I'll return the favor.

1. Check the output voltages from the power supply, particularly the voltages listed on the white label on the back of the plasma panel itself.

2. Disconnect the heavy cable from the power supply to the Z-sustain and see if the TV will stay on. Then reconnect it. (You may not see a picture.)

3. Disconnect the heavy cable from the power supply to the y-sustain and see if the TV will stay on. (You will not see a picture.) Do not reconnect it

4. Once again, disconnect the power cable from the Z-sustain and see if the TV will stay on.

Report your results.

PlainBill

[gunnahafta]

Re: Dead LG 50PS80ED

Sorry about the lakc of pics i didnt have means to attach any at that time. results of your suggested steps are:

Step 1. Couldnty test dont have a meter
Step 2. Powered on and stayed on. Also had the usual LG logo complaining about no input
Step 3. Powered on and stayed on. No picture
Step 4. Powered on and stayed on. No picture

As an extra step i plugged them both back in and turned it on. same thing happened, it powers on for a few seconds thengoes straight into standby. also when it did power on i hit a button or two on the remote and the white light on the TV flahsed like it usually does indicating its recieving the IR signal frmo the remote.

[gunnahafta]

Re: Dead LG 50PS80ED

Pics, i dont see any Bad Caps

[PlainBill]

Re: Dead LG 50PS80ED

Sorry about the lakc of pics i didnt have means to attach any at that time. results of your suggested steps are:

Step 1. Couldnty test dont have a meter
Step 2. Powered on and stayed on. Also had the usual LG logo complaining about no input
Step 3. Powered on and stayed on. No picture
Step 4. Powered on and stayed on. No picture

As an extra step i plugged them both back in and turned it on. same thing happened, it powers on for a few seconds thengoes straight into standby. also when it did power on i hit a button or two on the remote and the white light on the TV flahsed like it usually does indicating its recieving the IR signal frmo the remote.

1. Kind of hard to troubleshoot without a meter.

Steps 2-4 Inconclusive, indicates the power supply is PROBABLY bad, but I'd hate to buy a replacement on such poor evidence.

PlainBill

[PowerAmpFreak]

Re: Dead LG 50PS80ED

Sorry about the lakc of pics i didnt have means to attach any at that time. results of your suggested steps are:

Step 1. Couldnty test dont have a meter
Step 2. Powered on and stayed on. Also had the usual LG logo complaining about no input
Step 3. Powered on and stayed on. No picture
Step 4. Powered on and stayed on. No picture

As an extra step i plugged them both back in and turned it on. same thing happened, it powers on for a few seconds thengoes straight into standby. also when it did power on i hit a button or two on the remote and the white light on the TV flahsed like it usually does indicating its recieving the IR signal frmo the remote.

No hard feelings, but if you don't even have a meter, than you probably do not have the necesary knowledge about power electronics testing and fault finding. A plasma TV runs of lethal voltage levels, especially in primary part of the powersupply. Please take this as a warning and nothing else. This forum is full of people who put much time to help others with TV repair, but without a meter and at least a basic knowledge of electronics repair, we will have no chance of helping you, together with the risk of having yourself injured.

[mazdaverx7]

Re: Dead LG 50PS80ED

if you do go out and purchase a multimeter, please do not buy a cheap unit. i have been using Fluke brand meters for years and i recommend them. i have used cheaper variants from craftsman but never on home electronics/AC.

[PlainBill]

Re: Dead LG 50PS80ED

if you do go out and purchase a multimeter, please do not buy a cheap unit. i have been using Fluke brand meters for years and i recommend them. i have used cheaper variants from craftsman but never on home electronics/AC.

I strongly disagree with this statement. Fluke make some very good, rugged meters for the professional. They are a good investment for anyone who requires one for his job. While I do NOT recommend the cheap meters found on eBay for under $5.00, the fact is a meter suitable for the casual user can be had for a fraction of the price of a Fluke. I'm using one that cost under $25, and it has proved to be reliable and accurate.

PlainBill

[gunnahafta]

Re: Dead LG 50PS80ED

I just didnt have access to one at the time. It's not actually at my place and had to make a flying visit. Im by no means a professional, more of an amatuer. I've put together kits, made repairs, replaced caps etc before so i feel im competent enough but would happily welcome advise from professionals especially if you have some good advise to give when taking leter readings in high voltage areas like this. So before i get the meter and check it i welcome any advise you have to help.

P.S. Did anyone see any bad caps or anything else in the pics? I didnt see anything would like to know if someone could confirm that.

[PlainBill]

Re: Dead LG 50PS80ED

I just didnt have access to one at the time. It's not actually at my place and had to make a flying visit. Im by no means a professional, more of an amatuer. I've put together kits, made repairs, replaced caps etc before so i feel im competent enough but would happily welcome advise from professionals especially if you have some good advise to give when taking leter readings in high voltage areas like this. So before i get the meter and check it i welcome any advise you have to help.

P.S. Did anyone see any bad caps or anything else in the pics? I didnt see anything would like to know if someone could confirm that.

I'd say you are more of a hobbyist than an amateur, but that's my opinion.

When measuring the voltages always keep one hand in your pocket.

No obvious signs of bad caps.

PlainBill

[gunnahafta]

Re: Dead LG 50PS80ED

Cheers Buill i suppose you could be right there. I've put together plenty of PC's ans replaced bad parts etc when they are odvisouly bad.

I've heard the hand in picket tip, stops the current from using you to ground to the earth right.

[PlainBill]

Re: Dead LG 50PS80ED

Cheers Buill i suppose you could be right there. I've put together plenty of PC's ans replaced bad parts etc when they are odvisouly bad.

I've heard the hand in picket tip, stops the current from using you to ground to the earth right.

Yeah. Even standing on a concrete floor in your bare feet, it's unlikely enough current would flow to kill you if you touched the output of the PFC circuit. Holding onto the frame of the TV with one hand while probing the Va suppy - not so safe. Trying to see what would happen if you touched Va and -Vy at the same time - really, really foolish.

PlainBill

[gunnahafta]

Re: Dead LG 50PS80ED

Yeah. Even standing on a concrete floor in your bare feet, it's unlikely enough current would flow to kill you if you touched the output of the PFC circuit. Holding onto the frame of the TV with one hand while probing the Va suppy - not so safe. Trying to see what would happen if you touched Va and -Vy at the same time - really, really foolish.

PlainBill

I hear you. Im heading with the meter to take some readings in a day or two. You said to take readings, when refering ot the picture i attached (IMG_0358.JPG) are you refering to check the voltages marked on the board where the two heavy cables connect on the botton left and bottom right of the pic?

Hmm lokos like my level of expereinces is catching up with me

[PlainBill]

Re: Dead LG 50PS80ED

I hear you. Im heading with the meter to take some readings in a day or two. You said to take readings, when refering ot the picture i attached (IMG_0358.JPG) are you refering to check the voltages marked on the board where the two heavy cables connect on the botton left and bottom right of the pic?

Hmm lokos like my level of expereinces is catching up with me

Yes, those are the cables that carry power to the sustain boards.

PlainBill