LG 60PZ570 - Zsus replaced, still have issues

[JarrodHook]

Hi everyone,

I have had a interest in electronics forever, and as a hobby have tinkered with repairing things, taking them to bits, and so forth.

However, I have a LG 60PZ570 that is causing me to rethink my life!!

I purchased it for $100 as it had no picture, got it home, and it has the classic ZSUS issue, where in the picture is splotchy and dark.

I checked the ZSUS board and determined there were a few blown transistors, fuses, etc.

I looked up the repair kits, but the $70 shipping fee was a bit steep for me (I live in New Zealand) so actually managed to find a new ZSUS board.

Now, according to google, the board I got new, a EBR73561701, is compatable with this model of TV.

The previous ZSUS was model EBR67820001.

Anyway, got the new board, plugged it in, and I have the same issue, but also a buzzing from the new ZSUS board, probably from the coils I think.

Attached are some photos, and click here for a google video link to a video I took of the noise from the ZSUS.

I've checked the voltages and all seem ok. I did the jumper test with the control board and got test patterns ok. When I plugged my old ZSUS board in the TV shuts off straight away, which I half expected because I knew the ZSUS has busted transistors.

I'm just at a bit of a loss....is there a chance the new board isnt compatable? What should I do as far as my next troubleshooting steps are?

I have been following the service manual for my troubleshooting. (I also checked via search function too to make sure no one else has a simular issue)

Any advice MOST WELCOME!

[freakaftr8]

Re: LG 60PZ570 - Zsus replaced, still have issues

Check and double-check the coils on the Y and Z sustain boards. This model is known for cracking solder around the coils. Buzzing from the Z sustain can also be caused by voltage being carried across the panel to the Z sustain board from the Y sustain. Make sure you're getting good voltage at the Z sustain. I worked on a 60PZ950 before. This TV was a real pain in the ass to figure out

[freakaftr8]

Re: LG 60PZ570 - Zsus replaced, still have issues

Also make sure all screws are installed on y and z board. This model does not use a primary ground contact between each screw lead

[JarrodHook]

Re: LG 60PZ570 - Zsus replaced, still have issues

Hi FreakAftr8 - first off, thank you for taking the time to read my post and respond.

Honestly, half the battle sometimes is not getting so down about stuff not working and feeling alone!!

Your comment that they are a real pain in the ass actually takes a stack of pressure off me! So thank you!

Check and double-check the coils on the Y and Z sustain boards. This model is known for cracking solder around the coils. Buzzing from the Z sustain can also be caused by voltage being carried across the panel to the Z sustain board from the Y sustain. Make sure you're getting good voltage at the Z sustain.

When I first got this guy off of the NZ equivilant of Craigs List, I read that info and nearly shat myself with excitement, so did so. They were totally screwed on the old ZSUS, and the fuse was bung, and rather than repair, I got a new one, which is installed now.

The voltage at the ZSUS seems perfect, if not maybe off by one point or so, I can recheck and post those if it helps.

Also make sure all screws are installed on y and z board. This model does not use a primary ground contact between each screw lead

Thank you - you answered my next question ahead of time. I had only one or two screws in to keep it in place, but decided to screw all back in as a just-in-case.

I noticed the new board actually didnt come with those foam pads that are meant to be on the back of the ZSUS. I saved the old ones, and stuck those on now, just in case it was arching over.

I put the new ZSUS back in, screwed all in, and same issue.

However, I did unscrew the three screws on the buffer boards (I assume they are buffer boards on the right hand side, connected with the three thin wafer cables - apologies for lack of correct termonology and spelling - I am literally just recovering from a damn flu!)

To be safe, should I screw all screws in?

On another note, here is something interesting I thought, I did the jumper trick to run the test patterns on the control board, and left off the smaller cable, as highlighted on the attachment I stole and modified from the internet - and blammo - buzzing gone from the ZSUS.

Same screen issue occurs however, but no more buzzing!

Could the control board have a issue?

Thank you again for your time.

[freakaftr8]

Re: LG 60PZ570 - Zsus replaced, still have issues

No most likely what you're hearing is feedback resonance and brighter scenes or colors do not represent them buzzing in the z board. Check the new board for bad solder on the copper colored coils. Yes on this model all screws on every board must be installed for a to function properly

[freakaftr8]

Re: LG 60PZ570 - Zsus replaced, still have issues

There is the possibility of that new board being incompatible but I doubt it. I'm thinking coils on both sustain boards. Even the y having corroded solder on the coils will represent this issue.

[heavymachines]

Re: LG 60PZ570 - Zsus replaced, still have issues

Probably good idea to get some wick and suck out old and put in new soldier even if the joints look ok just to rule out coil issues.

[dick_barton]

Re: LG 60PZ570 - Zsus replaced, still have issues

I notice in your video that the boards do not have all their securing screws holding down the boards. I believe when reading through the Forum, that it is vitally important to have all securing screws in place and firmly done up or could cause you even greater problems.

[JarrodHook]

Re: LG 60PZ570 - Zsus replaced, still have issues

Hi to dick_barton, heavymachines and again to freakaftr8, thanks all for your replies.

Tonight I went down and hand screwed in all the screws in tight as I could, triple checked the tv for all the screws, all in and tight. Same issue occuring.

However, before tomorrows adventure of removing the boards and checking the solder, I followed up on that cable that I dislodged by accident.

So, the picture is a full screen now, only dark pools/patches when the tv powers on, for a few seconds, and then its a full screen.

I've taken another video, hosted in google video here on this link, just to show what happens when the cable is on and then removed.

I appreciate any insight into this.

A further FYI - while poking around the control board with my multimeter, I had black to earth and positive to the top then bottom of the crystal at point X1 on the control board.

When it was at the top, the buzzing would turn to a different frequency, and when to the bottom, it stopped totally.

When checking the screen, the test patterns stopped and the voltages going to the control board were down to 5v from the ZSUS, so I suspect that I might have earthed it and it triggered some kind of protection? Just thought I'd add that in there.

Thanks again for your time reading this, do check out that video and let me know it there might be something in that, or am I doing serious damage in playing, haha!

Thanks.

PS - also attached pictures of screen condition now, is this dot mal-discharge?

[freakaftr8]

Re: LG 60PZ570 - Zsus replaced, still have issues

This looks like y sustain issue now I would go ahead check soldering on all those coils of both boards but you're definitely getting closer

[JarrodHook]

Re: LG 60PZ570 - Zsus replaced, still have issues

Thanks for the support, I pulled off the Ysus tonight and checked, and resoldered the coils, reattached with all screws, but same issue occurs.

-Buzzing from the new Zsus board
-Buzzing disapears when that cable is disconnected.

I'll post some photos of the back of the boards tomorrow night my time.

For my curiosity, there is no corrilation between that cable being disconnected and the noise going away?

Seems a bit odd, and maybe a red heering?

Thanks, Regards, Jarrod.

[JarrodHook]

Re: LG 60PZ570 - Zsus replaced, still have issues

Hi there everyone,

Finally over my flu so I had some more time to look at this issue I am facing.

First, I got in touch with the team who sold me the new board and told them about the buzzing, so, another board is on its way.

Reading over a few old threads on here, I checked a few other things too, but I guess the most interesting is that the fuse on the new ZSUS board was blown, so I jumpered out to another one and fired it up, and the tv clicks on, then clicks off after a second...

...Which is odd. Odd because the old zsus board did the exact same thing...when I replaced the fuse, it clicks on, then clicks off.

I removed the new fuse and powered up the board, with the buzzing noise, and checked the voltage across the points marked VZB - nothing. Total zero.

So, new board may have been busted by me not screwing in all the screws, or, is there something else going on?

Also, just out of curiousity, I checked for continuity between the back of the panel and the screws and other points on the TV, and it all seems to be connected...is there a place where it can all short over, or is this normal?

Thanks.

JH

[JarrodHook]

Re: LG 60PZ570 - Zsus replaced, still have issues

Hi everyone, a update on this TV, a final update, and it's good news!

I got in touch with the supplier of the board, they sent me another one, free of charge, plugged it in, hand tightened all the screws, and BLAMMO. It looks amazing.

Thank you to all those who contributed, I now have my first 1080p tv, at 60 inches, and it looks awesome.

I'm going to add some external fans to keep the hot running ysus and zsus cool, apart from that, and the 30 kgs I need to lug up a flight of stairs to get it into my lounge, life is good!!!

Attached are some pics of the success.

THANK YOU EVERYONE.

[attainteddragon]

Re: LG 60PZ570 - Zsus replaced, still have issues

that is awesome. i'm still looking for a main board for one of these.
hope you let the supplier know that the second board worked.
enjoy the fruits of your labour.