Lg 60pa6500 black spots on tv

[pansatdishman]

Hello all I have a 60 kg plasma 60pa6500 the picture started getting black spots . What's the issue thanks?

[Biruslapio]

Z-SUS or one of the buffer boards, are there any black horizontal lines across the entire screen?

[pansatdishman]

No lines as far as I can tell just blotchy and hazy black it worked fine last night and never had any issues with it before. I installed fans for the main board on the back case a few months ago powered by the usb plug

[Biruslapio]

The mainboard is the last thing that needs fans for this model, Y-SUS needs top cooling priority.

This fault seems like some resistor opened at Y-SUS or Z-SUS, or a buffer board is failing, test those for shorts.

[pansatdishman]

Thanks which board?

[pansatdishman]

Sorry it's a pn6500
Sorry for the long reply I was at work so my dad was watching the tv and the picture was normal then all of a sudden the picture went black and hazey in the picture attached to this post. I have the tv apart what should I try thanks

[pansatdishman]

Heres the discoloration

[Biruslapio]

Ok, the PN is very different from the PA, I have a 60PM model, which is a PA with a better mainboard, don't know about the PN, this looks like a sustain problem.

https://www.badcaps.net/forum/showthread.php?t=39829 this is a very old samsung with a similar problem, X-Main (Z-SUS for LG) failure, might be only cracked solder joints, take out your Z-SUS and Y-SUS and check them underneath.

[pansatdishman]

I also noticed when it's in if I hook my android box up to it and use the cursor the cursor makes a temporary haze and imprint where it was , if this helps narrow it down?
Thanks

[RJARRRPCGP]

Originally Posted by pansatdishman

Heres the discoloration

I like plasma! If that was an LCD, that's classic LCD pressure-damage!

[pansatdishman]

Its plasma tv made in 2014

[RJARRRPCGP]

Originally Posted by pansatdishman

Its plasma tv made in 2014

A very-late one! I still wish I was able to snag a pristine one of those!

The closest we have, is one built in 2009, despite an excellent picture on ours, there's faint black spots, especially on the right of the screen, seen when it's all white on the screen. Is this a symptom of a hardware problem? I don't know right now. It honestly resembles dead LEDs on a recent LCD!

[pansatdishman]

Here's the z sustain board , does it look like theres anything wrong thanks in advance

[chrismurphy]

Z sus is faulty just replace

[pansatdishman]

Is there a way to test and repair it, I'm assuming you had this issue as well? Thanks

[Biruslapio]

Check resistance between the IGBTs, those 5 pin optocouplers, there can be no shorts between any of the pins of these 2 types of components. Low value resistors are also worth testing, they go open if a short occours in series with them.

[pansatdishman]

Thanks. It doesnt look like theres any known cold solder joints, has anyone had this issue before?

[Biruslapio]

If you don't have the means to repair it, might as well buy a replacement Z-Board, it all points to it, the rest of the screen is properly displayed, and these black spots are a sign of a bad Z-SUS, it is cheap in my country, but may not be at yours.

If it's expensive and you want to repair it youself you need to probe with a multimeter the components I pointed at #16.

[pansatdishman]

Good morning, I've been looking for my other multimeter but moved and can only find this one, will this one work?
Thanks

[Biruslapio]

yes, use the ohms scale.