LG 60PV450 no picture, audio working details inside.

[Shinju]

Hey all,

Fortune has smiled on me and now I have a second 60PV450.

This one power up, I can hear audio but I have no picture. I can hear buzzing from x it sound a little more loud then my working panel, the ysus is humming if I put my ear next to it.

Anyway after pulling the ZSUS I saw the normal 3 coil inductors solider failure 3 legs are completely disconnected.


I did t see any burnt components, if I was to solider the inductors back down on the board would that fix it or since those have separated it took out other components as well?

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

After soldiering all the coils back and replacing the fuse the tv just turns on, hear a click the ZSus buzzes and then click the panel shuts down, it does this 3 times then just sits in stanby.

If the z board is out of the circuit the tv comes on, no picture with audio.

[tom66]

Re: LG 60PV450 no picture, audio working details inside.

Vs, Va good?
Check Vsc, -Vy, Vzb as well.

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

After closer inspection of the z board there are a some blown SMD components.

Va/VS voltages were fine before the reflow of the inductor coils and replacing the blown fuse.

[tom66]

Re: LG 60PV450 no picture, audio working details inside.

Eventually the Z-sus ERC fault could lead to a failure in the Z-sus sus fets or other part of the Z-sus. Check them for shorts.

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

Will do.

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

ZSUS has at least 4 bad fets and a few smd parts that I have a feeling there is more. I ordered another one and once I get it I will redo the solider on the inductor coils after I test the unit first to see if the screen and video feed are pure from defects.


Only place I can find a ZSus was a place called NEWOSO.net, never heard of this company if anyone reading this has any feed back on them please pipe in!

I will use this old zsus as a learning tool and try to fix it.


Going to be sweet to see two of these side by side on my man cave wall!

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

Well, not sure if this is bad news or even worse news.

I got the replacement xmain in and the panel would not power on for more than 2 seconds it cycled 3 times then back to standby.

After fiddling i finally got it to come on and screen prime but the image looked like a squid puked ink over a white canvas.

After more fiddling and triggering the test patterns I got this (see photo below)

Like a dummy I pushed my fiddling a little harder and I accidentally slipped my probe when testing the VS voltage on the y main board plug I believe I crossed the GND and arced and TV shut down.

Now it turns on flashes an inky looking image on the top half of the screen for 1-2 seconds then image goes away screen is black but the TV is still running.


The voltages on the VSC/VY and VZB (xmain) were all very low.

This image in the photo after being on for a few the ink looking issue was going away before I mucked things up.

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

Ink issue was going away the longer it was on till I mucked things up.

Now I cannot even get the test patterns going.

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

/bump

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

Would a bad controller board cause low voltage on VSC/VY and VZB ?

I am almost positive this other Xmain is shot, the Y-main also, and now possible the lower buffer.

When I ran the Panel with only the top Y-drive the Y-main stayed active but no image on the top half of the screen, again all 3 board voltages were very low. I will and run the panel with no Y Drive buffers attached and see if anything changes.

Ugh... I am not sure what happened when I slipped my probe but as I said earlier in the thread the Panel comes on the screen starts to show white/black ink effect on the top half only and shuts down after 1-3 seconds.


@Tom66, I did not see the 60PV450 service manual on your hosted site, do you have one you haven't uploaded yet? Thanks for your input so far!

[tom66]

Re: LG 60PV450 no picture, audio working details inside.

I probably won't have a manual for this newer set.
If you have a scope, check the output waveforms from Y and Z.
Personally, I doubt the control board is bad, or I would expect no image at all.
I suppose it's not impossible but I think you have two faults here.

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

As of right now I cannot get the test patterns to show up after I probe slipped.

Also, for others reading this who might encounter this issue.

I have Panel make PDP60R30000. Can I use the X/Y/Buffers from PDP60R30110?

This panel specifically only has 2 PDP revisions and 2 possible x boards and 2 possible y main as well as Y-drive buffers ect.

Would it be safe to assume those boards are interchangeable between these 2 panels?

I will have access to an oscope when I head to my friends place to help him with his panel.

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

I probably won't have a manual for this newer set.
If you have a scope, check the output waveforms from Y and Z.
Personally, I doubt the control board is bad, or I would expect no image at all.
I suppose it's not impossible but I think you have two faults here.

Y-X boards faults?

I am going to check the lower Y-drive for shorts tonight.

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

I pulled both Y drive buffers and the sub voltages on the boards remain low. So I am pretty sure both x and y boards are shot.

Tom66, I did your Y drive buffer check to see if there was a shorted IC on the lower buffer and I coudnt find one I used the diode checker no solid beeps, now I am confused as to why the bottom of the panel is not igniting and the color test patterns are not working now.

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

I went ahead and ordered tested and working Y/X boards as well as Y Drive buffers. lol somehow I feel this is going to be a spendy lesson!

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

@tom66

I borrowed a ATTEN ADS 1062CAL Scope, The TP on the controller board reflected the wave as shown on the service manual, as for the Ysus I was getting a Wave but not sure if I was correct (new to o-scope) the Xmain was showing nothing on the scope when the probe was on TP jumper for O-scope readings.

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

Got a different xmain from shopiimmy and put it in and I have ZERO VZB voltage this is with the Ysus completely disconnected.

This is getting frustrating!

I am about to take a shot gun to this damn thing...

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

Ok, being that I am flying blind here with no service manual I am now just going to use this thread to document my finds and outcomes.


So with the 60" PVXXX series you must have the Ysus and xmain hooked up (no buffers and no flat ribbon cable connected to the lower buffer) to the control board and SMPS to get VZB reading off the Xmain, you will not get any VZB voltage without the y/x sending 18v back and forth to the controller board.

I don't know of any other method to test the xmain board solo.

So my xmain is reading 105.74 VZB (zbias) panel is 110 spec.

[Shinju]

Re: LG 60PV450 no picture, audio working details inside.

Tom66

I bought a service manual for this unit, it appears to be a flow chart/repair schematic for mainboard functions.

If you want to add it to your database I can send it to you.