Occasional red picture on LG 60PZ950

[r-p]

I wrote in another thread that it worked OK, and a YouTube clip from my laptop through HDMI worked flawless for minutes.
But a long term test with a slide show from USB reveiled the below issue: the sides should be black but were often red. Also parts (right side) sometimes still had some black in them. The issue would come and go.




Still of Grand Canyon that should have black edges to left and right instead of red. There is also some red IN the photo that shouldn't be there.

As mentioned in the other thread it showed red spots and smears the moment I switched it ON without an input source when I got it, and they were all gone when I had the back off for checking voltages. Va and Vs (iirc) are <1V too low and I left them like that as I didn't know if the adjustment potentiometers are accurate enough to improve on those deviations.
I found small issues, and resoldered powersupply board and the coils on the Z and Y board (see pic below). The above "red" issue is the current state after my 'resoldering'.


Any clues are welcomed!


Fixed cracked soldering on Z and Y boards

[Alastair E]

Re: Occasional red picture on LG 60PZ950

Typical stress fracture in lead-free RoHS Crap solder....

Lead was in solder--For a Reason!

RoHS directive--Was Supposed to protect environment--But has contributed to much more Waste electronics than anything else!

Damned greenie meddlers!

[r-p]

Re: Occasional red picture on LG 60PZ950

I guess you're referring to the last pic Or the red-issue too?

We switched to leadfree at work for repairs. I found it worthless to work with. And that's an understatement. An electronics supplier even kept using leaded solder for the powerconnection (as allowed per ROHS directory iirc) to prevent this stress cracking

[r-p]

Re: Occasional red picture on LG 60PZ950

I readjusted all voltages (Vy, Vs, Va, Vsc, Vsb) but all were within 0.7V to begin with.
I checked all FETs and diodes as per the repair manual (downloaded from Electrotanya) for "picture problems". The picture and numbering on my board were not the same as in the repair manual. I only did the Y-sus board (chapter "A8" in the manual). All values were OK apart from some FETs that were ~0.65V instead of within the 0.45-0.55V range.

I read this thread which describes my problem very accurately. So I payed extra attention to the ribbon cables from the control-board to the rest of the TV and between the mainboard and the control board.

I tested with a USB stick and a slideshow (like last time) with the back off and put a hairdryer on the main and the control board. There was a momentary "red pixel issue" but only for one or two slides and I could not reproduce it afterwards (I had just switched from the main to the control board, so no clue which was the culprit or if my hairdryer even had any influence).

I left it on for an hour (still with back off and without hairdryer on it) but it did not fail again. The processorheatsink (on mainboard) was warm, the heatsinks on the Y-sus and Z-sus were very hot. On the limit of touchable (~45-50C?). Nothing to worry about, but I try to keep my heatsinks below 'too hot to touch' temperatures.

I will continue testing with a 2kW spaceheater (gets hotter than the hairdryer, but the third option, a paintstripper, becomes too hot).

Any thoughts or advice is welcomed.


(Edit: while looking for the service manual on Electrotanya, I originally only found a single manual (60PZ950 PD12A), now I find 7, so I will see if I can find one that is a closer match to mine. Cannot yet locate "PB12A", "B" or "C" on my TV or PCB's).

[r-p]

Re: Occasional red picture on LG 60PZ950

Added a heatsink with a stickypad (came with the heatsink, so I assume it has the workings of heatsinkpaste) to the processor of the control board.

Added a fan to the mainboard heatsink, but it was too noisy, so I removed it again. Added three fans to the outside and the top of the back-cover. So the natural convection that this unit relies on for cooling can be increased by the fans (they suck air out of the top ventilation holes).

They are 12V fans that I hooked up to the 5V supply via a switch (totally silent, but obviously slow moving). They are NOT on, and the issue has not returned yet. I have watched a movie on it and the kids use it for the WII, so about 5 hours of trouble free working with the back attached.

If the issue returns, I will switch ON the fans to see if the issue resolves itself then.

The previous gaming monitor is a Hitatchi 42PD3200 (800x480 plasma) that had very large green pixel issues, but has been working at an acceptable level for the last two years since adding 8 (!!!)fans. They are serieswired per 2 on a 12V supply with series resistors so they have like 5 speedsettings, but they are noisy in all of them But its just a gaming monitor for the kids

Crappy animated gif before and after

I threaded the heatsinks and they are all inside the housing, but for the LG I opted for a simpler solution (cable-tied them to the back as I am not too sure it is even the solution to the problem).

[ReeceyBurger123]

Re: Occasional red picture on LG 60PZ950

Added a heatsink with a stickypad (came with the heatsink, so I assume it has the workings of heatsinkpaste) to the processor of the control board.

Added a fan to the mainboard heatsink, but it was too noisy, so I removed it again. Added three fans to the outside and the top of the back-cover. So the natural convection that this unit relies on for cooling can be increased by the fans (they suck air out of the top ventilation holes).

They are 12V fans that I hooked up to the 5V supply via a switch (totally silent, but obviously slow moving). They are NOT on, and the issue has not returned yet. I have watched a movie on it and the kids use it for the WII, so about 5 hours of trouble free working with the back attached.

If the issue returns, I will switch ON the fans to see if the issue resolves itself then.

The previous gaming monitor is a Hitatchi 42PD3200 (800x480 plasma) that had very large green pixel issues, but has been working at an acceptable level for the last two years since adding (noisy) fans.

Animated gif before and after

Good stuff One thing to do is seal off the other air gaps with something as the fans will just be sucking air through them rather than the Tv.

[r-p]

Re: Occasional red picture on LG 60PZ950

Double post

[r-p]

Re: Occasional red picture on LG 60PZ950

TV has worked flawlessly for >3 months now (2-6 hours a day) until yesterday. The issue resurfaced, went away completely for an hour or two and resurfaced again.

Finally a chance to use the fans but alas, they made no real difference. They *might* have reduced the intensity of the red a little, but that is hard to say with an ever changing image (normal TV broadcast).

I bet my energybill doesn't mind the switch from a 60" plasma back to a 37" LCD...

Will continue the search for a solution when I have the time. Will probably start with simply reseating the flatcables.

[r-p]

Re: Occasional red picture on LG 60PZ950

I probed all connectors with a wooden spoon, but no luck.

I reseated the flatcables one by one on the controlboard and this didn't fix anything.

I resoldered the connector for the flatcable between the input (main) board and the controlboard (I was assuming this was equivalent to LVS-something cable often mentioned in Panasonics or Samsungs???), but despite copious amounts of flux and the SMD-dragging procedure, this was not a great succes, so I only did the control board side.
After making sure there were no bridges between the individual pins of the connector (USB microscope), I put the controlboard back, but nothing has changed (at least I didn't make it worse ).

Any ideas? Since the issue was totally gone for months, I doubt it was defective components.
I will recheck all voltages tomorrow and try to follow all tips in here.

[r-p]

Re: Occasional red picture on LG 60PZ950

I have been fiddling with the voltages, but could not find any settings to get it better.

I used this thread to trigger the testimage setting of the control board (post 11).
As far as I could tell, that seems to work just fine, although the white screen that scrolls to black was less than perfect. But this only meant that the white opposite the black scrolling part was not bright white but somewhat less 'light' white. Much like the pics in the thread linked to above (post 12). I videotaped the test sequence, so if needed I can post that on youtube.
But I saw no real red-issues. So does that mean it is caused by the inputboard somehow? Or is that conclusion to simple? Most times it is NOT blamed on the input/mainboard, but on the control board. I think that flatcable is the one I did check for continuity. Then again, flatcables can seem to have continuity, but a slight bend can open up a break very easily...

It's a horribly big ugly thing standing in our livingroom with the back off. But I cannot throw it away as long as I am not convinced it is unrepairable (for free)...

Post I added in another thread regarding info posted by Tom66:

It's a high speed digital data link encoding the individual pixel data. If the connection is loose, an impedance mismatch is created, which causes a reflection (think of a water tank: if the end of the tank is a solid wall, the signal (wave) will get reflected back, but if it's a matched end, no reflection is created.) This causes distortion on the signal causing your problem.

As for why it happens, I suspect it's related to it not being correctly seated at the factory and slowly working itself loose from thermal expansion.

This is a very believable explanation, but/and the only decent one I can find after reading 100+ threads on the subject.
Can I ask where you got this insight?

I assume this will be similar for different brands. My LG had this red mist issue, it disappeared for 3 months of intensive useage after a load of soldering possible dried joints and reseating connectors and it reappeared. Supposedly (but poorly documented) the only fix is buying a new control board.
When combining the bit issue with the new board theory, I end up with a bad connector or so.
It has a fine pitch connection to the YSUS that I reheated with difficulty. And it has three much finer pitched connectors to three pcb's at the bottom of the screen. No chance of resoldering those without messing up.

Are these three likely the culprit or would this only affect 1/3rd of the screen? (I have no clue what those pcb's do)

[r-p]

Re: Occasional red picture on LG 60PZ950

After being in the way for years and years and even having bought a JIG to program it, it is time to give it a final go.

Been postponing it for fear of messing it up and I am surprised the wife hasn't filed for divorce yet with that thing lying around.

So, what do I need?

I found a zip-file containing e.g. an excelfile named "SVC ROM Mastersheet" and an LG PDF updated 04/21/2010 detailing a Panel maldisharge fix.

One reason for postponing is also because the Excelfile lists 60X5A and 60X7 as ctrl board versions, but I have 60R3 on the ctrl board...

(EDIT: duh, I thought the panel was much older but looking at the pics again, MFDT turns out to be 2011 so quite logical the 2010 zipfile does not list my panel/ctrl-board... Writing LG as we speak tosee if they will give me newer software)

HELP!

[r-p]

Re: Occasional red picture on LG 60PZ950

Dutch LG are utterly useless. They mention that it is not possible to update via USB (I told them I have a JIG programmer) and that I should use a Chromecast if I wanted to keep using the apps.



Maybe I'll try LG international/USA.

[diif]

Re: Occasional red picture on LG 60PZ950

It seems it was a heat related issue on the mainboard, that suggests an issue with the BGA under the processor to me.

[lotas]

Re: Occasional red picture on LG 60PZ950

Here I found the firmware for the Logic 60r3_CTRL

[r-p]

Re: Occasional red picture on LG 60PZ950

It seems it was a heat related issue on the mainboard, that suggests an issue with the BGA under the processor to me.

Thanks, that's new information for me. Any links to discussions/articles about this?

Here I found the firmware for the Logic 60r3_CTRL

Thanks! Where did you find this? Personal stash or somewhere on the net (which means I suck at searching...)?

Whenever I get the balls to go at this again, I will gve it a try.

Just repaired another lead-free-solder-sucks problem on a mouse, so if diif does have more info, I still have that as a back-up-plan (though BGA soldering is far beyond my capabilities).

[nomoresonys]

Re: Occasional red picture on LG 60PZ950

best advice is recycle that energy hog, you will be thanked by a lower electric bill and nobody will get a double hernia trying to move it and they can be a money pit once they get old and shit starts going bad, not worth the effort.

[r-p]

Re: Occasional red picture on LG 60PZ950

best advice is recycle that energy hog, you will be thanked by a lower electric bill and nobody will get a double hernia trying to move it and they can be a money pit once they get old and shit starts going bad, not worth the effort.

As it happens, I produce a lot more electricity that I use (>2MWh) so as long as I subtract production from usage, it's OK. Also means it WILL retire within a few years even if the repair is succesful (coming 10 years will see the subtractionpercentage fall to zero).
(Do have two 55" Samsungs with different issues waiting in line to be combined into one functioning one).

[nomoresonys]

Re: Occasional red picture on LG 60PZ950

The biggest problem is the burning of coal, there is ABSOLUTELY no need to burn coal in the 21st century, the filthy shit should be left in the ground, not destroying the air we all need to breath for survival. I blame the greedy politicians of the world, as long as there's a buck to be made they don't care about anything else, no clean air, no clean water etc, etc.

[nomoresonys]

Re: Occasional red picture on LG 60PZ950

What I find just plain hilarious is, I saw on the news, that they want to ban gas cooking stoves, in the U.S.A. anyway, which do serve a good purpose, as in not destroying by drying out everything cooked in the oven like electric stoves do, yet they didn't mention one word about how coal is destroying the atmosphere, sadly you can't make this stupid shit up, pure ignorance in motion.

[R_J]

Re: Occasional red picture on LG 60PZ950

Gas water heaters need to vented, I wonder why that is?