LG 60ps60

[Tvbob]

Re: LG 60ps60

In my correspondence with the repair company previously mentioned.
They knew the board numbers before I sent them. Only after they received them I was told they could not service them, Because they could not jig them.
I assume they have some common plasma panels at there shop.
Attached are the buffer pic's (The lower buffer with the silicone everywhere was not me) Thanks

[Unspun01]

Re: LG 60ps60

If they could not jig the boards, then how can they expect to repair and test the boards? Unfortunately, I don't think they helped you in this situation. They should have refused the business if they did not have TV or jig to test the boards.

What's the deal with the silicone? Has the lower YDRV board been repaired previously?

There is a tutorial somewhere for how to test these LG buffers, but I don't know where.

It's possible the repaired one is failed again, but no way to be sure until tested.

Again, it is strange that you have raster, and video (albeit not good video) but still leaning toward YSUS or ZSUS because of the overheating resistor, and/or ZSUS due to maldischarge symptoms...

Perhaps someone else knows the buffer testing procedure or tutorial?

[Tvbob]

Re: LG 60ps60

Where to go from here..
This tv is one of 3, 60" lg plasma tv that I have bought broken off Craigslist recently
I am a retired Tv repair man and this is now a Hobby. Have a garage and a detached garage full of tvs. My trash man hates me.
Back to this set .
I found an upper buffer and a Ysus from the same seller on ebay $180.00
If I bought them and installed with out my lower buffer and that resistor pops
it would be the Zsus ??? LOL

[Tvbob]

Re: LG 60ps60

Curiosity got the best of me..
I odered another Y sus and upper and lower Y buffer boards..
Resistor that Unspun01 pointed out (Thanks Again Unspun01) gets Hot with in 30 seconds.. Maybe Try a Z buffer? Or is this a BAD Panel?
All voltages are Good including Z bias

[Unspun01]

Re: LG 60ps60

Hi TVbob:

That 0.22 ohm fusible resistor is a high wattage resistor, so it may get hot under normal operating situations but should not normally fail.

I do not understand your reply and incomplete photos. Is your TV working now? Your TV photos do not show the complete TV screen, so I do not know if you have good image, or missing parts of it. The last photo looks ok?

It is likely that one or both of your buffer boards has shorted driver IC on it, which puts excessive load on the YSUS board.

If your TV is working with current YSUS, and upper and lower YDRV boards, then call that a win.

DO NOT re-connect the other buffer boards to your functioning YSUS until you test them both. Re-connecting the suspect YDRV buffer boards could damage your YSUS.

If you can test the buffer boards and see which one is bad, you may have a good spare to re-test with. And if your new YSUS is working, you can use it to help troubleshoot the two other YSUS boards that are broken.

If you can fix the broken YSUS boards, then you have valuable parts for your other two 60" TVs.

AGAIN, DO NOT RECONNECT THE OLD BUFFERS TO NEW YSUS WITHOUT TESTING THEM FOR SHORTS.

[Tvbob]

Re: LG 60ps60

Sorry for the confusion.. The replacement boards display a picture that look exactly like the pictures in my first post in this thread
I took quick pics with my phone today because I did not want to leave the tv on too long.
That resistor gets too hot too quick.
It appears that this Ysus board buffer "set" Works like the Y sus board and buffers that I took out Today.
The 3rd pic in this post shows the lines the best

[Tvbob]

Re: LG 60ps60

The TV's that I mentioned in post #23 are different models

[Unspun01]

Re: LG 60ps60

Hi TVbob:

I don't mean to be rude, but these are terrible pictures...lol... You have the TV in front of you, but we do not. It is near impossible to understand what you are referring to, especially without seeing the entire screen at once, and then a closeup of that same paused image.

Please upload some high resolution photos (DO NOT USE A PHONE CAMERA) of the ENTIRE screen. Top to bottom, left to right.

It is impossible to judge the quality of your TV image from the programming you are using. Try displaying standard non-moving color bar images, or the following: all white, all red, all blue, all green, all grey. This will quickly identify image problems or lines or artifacts.

What are you referring to as "lines" in the 3rd image? All I can see is an A&E logo that maybe shouldn't be there?

This looks like image retention, or possibly screen burn-in. You do not know the history of this TV, so it is possible to be plasma screen burn-in if the previous owner left the TV on pause or watched 4:3 format for extended periods of time.

If it is image retention, or appears like image retention, I advise to check the panel voltages supplied from the power supply. The correct voltage is clearly listed on the panel label sticker. VA, VS, VSC, Vscan, etc. check if these voltages match the panel specs. If your voltages are not within spec, you will have picture quality issues.

This may still be mal-discharge issue from ZSUS board, but may also be an adjustment issue. Again it is not possible to tell from your photos.

If you are using regular broadcast programming, it would be helpful to have photos from TWO different TVs with the same image paused... One display will tell us what the image "should" look like, and one image will show us what your 60" TV is "actually" displaying.

[Tvbob]

Re: LG 60ps60

Yes they are..sorry.
I was using my phone And using text to email them to myself.
I imagine they got resized on the way to the email server.
I cannot find software for my digital camera to install on this pc.(still looking)
My phone has 10 mega pixel, used a usb cable to copy these photos off the phone
Also the resistor that I have made mention of has opened while taking these pics also
I now have 2 Ysus and upper and lower buffer board (sets) With the same symptom (resistor opening)
All voltages are the Good and spot on.
Using a 720p feed off a video distribution amplifier feed by a satellite receiver.
I could not get this to display its test pattern this time I think it was shorting pins 3 and 4 with lvds cable removed.
I was in a hurry trying not to pop that resistor LOL

[Tvbob]

Re: LG 60ps60

Ordered a Z sus Today.
Question Why does the Zsus need input from the logic board if the is only 1 electrode connection to the panel, maybe power modulation?

[Tvbob]

Re: LG 60ps60

answer

[Unspun01]

Re: LG 60ps60

Yes, since the Z-sustain board is responsible for panel erase and discharge, it needs to know when to do those things.

It is only one electrode connection (Really, there are multiple - 2, 3, sometimes 4, but they are all the same thing). Imagine an ETCH-A-SKETCH toy. The Z-SUS performs the same function as sliding that erase bar back and forth to erase the image you just drew. You want the Z-sustain to perform it's erase function (and energy recovery) at a certain time with certain timing so it does not interfere with the YSUS creating the image.

This is why mal-discharge or poor image quality are often attributed to malfunctioning Z-SUS.

[Tvbob]

Re: LG 60ps60

Fell fellow Enthusiasts..
I replaced the Z sus today And still have the same prolbem with the 2,2 ohm 1 watt resistor on the Ysus getting real hot real quick, (It will open in minutes if left on) I still have a normal picture with random vertical lines across the screen.
I have been threw 4 or 5 Y sus boards and 3 complete sets of Y buffer boards. This is the problem the Tv had when I bought it. There were no attempts to repair before me.
Can a plasma panel fail in this way?
Or should I try a logic board?

[Unspun01]

Re: LG 60ps60

Random vertical lines? This is not issue of YSUS or ZSUS or Y-buffer boards.

If you installed this many new YSUS and new upper and lower Y-buffer boards and a ZSUS board I would expect tv should be working by now.

Could be an issue with lower buffer boards along bottom of panel. Or logic board. Describe the lines for us. Completely random? Or repeating pattern? Completely across screen? Or localized to one area? Are the lines completely top to bottom? Or does it seem like some fade part way?

[Tvbob]

Re: LG 60ps60

OK, I decided to jumper in a parallel 2 ohm 5 watt resistor across the resistor that gets hot and opens on the Ysus board so I can leave it on longer to make more checks.
What I have found, One side of resistor is connected to VS (193.8V) on the other side (load) I have ( 193.7V) That Must supply the two 2SK3453 Toshiba MOSFETS that get warm faster than the other power FETS ,ect. on the board.All voltages good. VS 194,VA 67, -vy 178,vsc 140, z bias 104
I have Random vertical lines and stationary horizontal bands in the picture for the first 90 seconds or so. then they gradually disappear.
I am pulling 21 milliamps thru that paralleled 5 watt resistor and it gets warm The first two pics when it was cold the 3rd pics starting to warm up
I think I might try a logic board ?

[Unspun01]

Re: LG 60ps60

Hi TVBOB:

I still cannot tell how good or bad your image quality is from your pictures. Your photos are always at an awkward angle, and many are only partial screen shots so we cannot judge localized or complete issues across the screen.

Please take photos at eye-level, and straight-on as if you were actually watching the TV. It is very hard to look down at the screen or at some angle like you are doing and analyze the image.

At angles, a camera may capture individual pixels, but a few inches further away it cannot and the colors blend differently. If the camera is the approximately the same distance away from the screen (straight-on) then all areas of the image are captured equally.

As it is, these photos show "moire" patterns and other things the camera is doing that things I can't quite tell what's good or bad.

Also, I have a correction:

I mistakenly identified that resistor as a 0.22 ohm resistor by misreading the color bands on my small phone screen. I think the bands are red/red/gold/gold so the resistor should be 2.2 ohm.

Therefore, a 2 ohm 5W resistor would be close to original.

[Tvbob]

Re: LG 60ps60

Thanks unspun01 I made the same mistake on the gold multiplier on resistor also The original resistor is a 2.2 ohm 1/2 or 1 watt..red,red,gold,gold.
The reason the bad angle on my pictures. The TV is hung from the floor joists in my laundry room, too cold in garage.
I have made progress, The Lines that I can't get clear pictures of go away after a 10 second blast of hot air from a heat gun on the logic board I suspect one of the smd electrolytic caps
I ordered a logic board today.
I hope it takes care of my over heating resistor also.

[Unspun01]

Re: LG 60ps60

I have made progress, The Lines that I can't get clear pictures of go away after a 10 second blast of hot air from a heat gun on the logic board I suspect one of the smd electrolytic caps
I ordered a logic board today.
I hope it takes care of my over heating resistor also.

Thanks for the information. I have not seen a bad logic board yet on 20 or so of these LG 60" plasmas - mainly YSUS or ZSUS repairs.

If your logic board is the culprit, it could be introducing noise onto the wrong signal lines and causing the transistors to run hot because they are not switching on or off at the appropriate times, and therefore conducting longer than necessary (hence the heat)

Best of luck with that swap.

If heating the logic board works, it's possible the issue is surface mount caps on the logic board, or bad BGA connections. If you suspect bad smt capacitors, you could try soldering the legs of a thru-hole capacitor with same capacitance across one cap at a time and see if the problem goes away. Parallel caps add capacitance value so any that are out-of-spec may improve immediately if paralleled. The values are 22uF/16V, 100uF/16V and 330uF/16V on that board.

If you have an ESR meter, I would test those caps first before replacing caps or pulling the trigger on a new logic board.

Can you try to localize the heat? Like turn the TV on, and touch the top of each capacitor one at a time with a clean soldering iron for a few seconds? You can use a bit of flux on top to help transfer heat easier.

You may be able to narrow down the specific capacitor. Or rule out the capacitors entirely...

[Tvbob]

Re: LG 60ps60

I used a can of freeze spray (I don't think they make it any more) after I heated up the logic board with a heat gun. One drop of the boiling freon on the big 330uf@16 v caused many more lines.. Checked the cap in circuit with a meter = 68 mfd
I already had a logic board on the way only $29.00 ebay so I never jumped in any caps. I did not want to stress my Y sus board any more.
I have since changed the logic board and the set is Fixed!
The before mentioned 2.2 ohm resistor and associated mosfets run cool now.
Thank you agian Unspun01 for noticing that blown resistor in my earlier posts. So in retrospect The cap went bad on the logic board causing noise (lines) in the picture also drives the sustain boards, making components stay conducing too long (Back when I was in school it was called Duty cycle) And that resistor would pop before I had Time to make any conclusive checks. lol This is a well built set. I think I will keep it as I now have two complete spare sets of Y sus boards and buffers

[Unspun01]

Re: LG 60ps60

Hi Tvbob:

Great news! I'm glad the issue is resolved. I've repaired several of these TVs and have not yet seen a bad logic board but I can see how it's failure would affect YSUS. If you replace the 330uF cap make sure you check the other caps also in case the others are suspect.

Another tv saved!