HP LP3065 Not working (Flicker, noise, patterns)

[antome]

Hello,

I have a HP LP3065 30" monitor that is broken.
I have tried looking around for other threads with a soltion for this for a while now but have not been able to find one.

Whenever I turn it on it just starts flickering like crazy and I sometimes hear a high pitch noise. When it first started to happen it would only flicker whenever it had been turned of for a long period of time, but now it is constantly flickering (or making random patterns that changes depending on what the computer is trying to display).
I have opened it up and looked at all of the PCB's inside the moitor for obvious signs of damage, but with no luck. All the capacitors on the PSU appears to be in good condition.

I have some experience with electronics so I am not afraid to do some troubleshooting, but I just have no idea where to start. Any help would be greatly appreciated.

PSU: Liteon PA-3171-2-LF Rev: 01

I live in Sweden: 230V mains 50 Hz

Best,
A

[selldoor]

Re: HP LP3065 Not working (Flicker, noise, patterns)

Was it faulty when you got it - have you ever seen it with a clear faultless screen.
You could spend a lot of time testing only to find its a faulty panel.

[klkmalik]

Re: HP LP3065 Not working (Flicker, noise, patterns)

Maybe possible T-con board problem, and check inverter transformer with high volt cap ccfl lamp wire loose, some time inside arcking/

[Rtech]

Re: HP LP3065 Not working (Flicker, noise, patterns)

I would certainly suspect the CCFLs in the first instance

[antome]

Re: HP LP3065 Not working (Flicker, noise, patterns)

Selldoor: I have had it since it was new so it was not faulty to begin with.

klkmalik: The ccfl lamp cables seemed to be connected just fine. I don't know what you mean by inside arcking? And regarding the possible T-con board issue, do you have any suggestions on how to proceed to troubleshoot that?

[selldoor]

Re: HP LP3065 Not working (Flicker, noise, patterns)

I think K may mean the wire connected to the ccfl where it joint the ccfl sometimes burns away the insulation then it arcs accross to the frame.

Reall we will need pictures of the inverter board and the T con. Start with the inverter board it may be eadier to get at.
If it is currently all connected up first check the cable bewteen the main board and the
Tcon - take it off CAREFULLY and reseat. Then try it again

[antome]

Re: HP LP3065 Not working (Flicker, noise, patterns)

Ok, So if I were to check for a burt isolation at the ccfl would I have to take apart the whole panel?

I have tried to disconnect the cable bewteen the main board and the
T-con board before with no result. I have taken some photos of the inverter board that I will attach below. If you need photos of the T-con then I can upload some also, but that board is a pain to get out.

[selldoor]

Re: HP LP3065 Not working (Flicker, noise, patterns)

Hi - ok so no capacitors on the inverter so Tcon would be next.

Ccfls It depends on the type of panel - this size- probably yes you will have to take apart BUT sometimes you can see the ends of the tubes and the wiring.
IF you can wire it all up when the panel is out of the frame you can sometimes tell if a bulb is gone.
What you could do while its in it present state is to test each bulb one at a time to see if one flickers - its hard to tell as I dont think they will stay on long enough. Another idea would be to make up a couple of spare test lamps and see if when using them the flickering stops.
Here:https://www.badcaps.net/forum/showth...ght=test+lamps

[budm]

Re: HP LP3065 Not working (Flicker, noise, patterns)

The screen shot on the first post shows bad looking screen which can be due to poor power supply, bad T-CON, etc.
The flickering on the screen, is the lamp flickering or the T-CON is flickering (T-CON is going on and off)?
You may have multiple problems.
To find out if the backlights are flickering or not, disconnect the LVDS cable to the sceen, then look at the screen in dark room to see if the backlights are flickering or not.

[antome]

Re: HP LP3065 Not working (Flicker, noise, patterns)

If it is capacitors that you are looking for then I can tell you that the T-con board does not have any capacitors either. I looked at it before when I did my own "looking around". However if you want me to take a picture of it anyways then I can do that!

I find it kind of strange that the ccfl could be the issue.. Why would that affect the image like this? If the backlight itself was flickering wouldn't that affect the brightness of the display rather that affecting the "content" that is displayed? Again, I know nothing about this so I could be wrong..

Anyway, I figured I'd go ahead and upload a video of the problem just so you know exactly how it looks like:
http://www.youtube.com/watch?v=oT87J...ature=youtu.be

Thanks for your help so far!

[selldoor]

Re: HP LP3065 Not working (Flicker, noise, patterns)

I think we are thinking Voltage regulators or bad cable connections.

What does it do when you try the on screen menu

[antome]

Re: HP LP3065 Not working (Flicker, noise, patterns)

I have disconnected and reconnected all cables (I think) so I dont think the connections are bad. Unless the connector or cable itself is worn or broken is some kind of way. Or even broken solder joints perhaps... I will take a closer look at that. Any info on testing the voltage regulators?

The monitor does not have an on screen monitor actually. Only input switch and brightness adjustment. Nothing happens when I press them.

[budm]

Re: HP LP3065 Not working (Flicker, noise, patterns)

Bad lamps will not cause all those lines on the screen, but did you disconnect the LVDS cable and see if the backlights are on steady as I suggested.
There are lots of caps on the T-CON board, not the canned type that you see on the power supply board.

[antome]

Re: HP LP3065 Not working (Flicker, noise, patterns)

Yes of course a lot of SMD caps, but those seems to be alright.. Just to be clear, you mean disconnect the cable going from the motherboard to the T-con board and not the flex cables going from the T-con to the 'panel' ?

[budm]

Re: HP LP3065 Not working (Flicker, noise, patterns)

Those MLCC when they failed, they failed shorted due to crack in the body.
The LVDS cable is the cable between the main board and the T-CON board.

[antome]

Re: HP LP3065 Not working (Flicker, noise, patterns)

When I disconnect the LVDS cable nothing happens when I turn I on. The screen just stays black. The green LED comes on for about a second and then turns orange, indicating that the monitor is in sleep mode.

[selldoor]

Re: HP LP3065 Not working (Flicker, noise, patterns)

Is that with a source connected and in a darkened room

[antome]

Re: HP LP3065 Not working (Flicker, noise, patterns)

Yes!

[budm]

Re: HP LP3065 Not working (Flicker, noise, patterns)

"The green LED comes on for about a second and then turns orange" if you hook up the LVDS, will the lamp stay green? I do not believe this monitor uses any error signal from the T-CON.

[antome]

Re: HP LP3065 Not working (Flicker, noise, patterns)

Yes, I just tried that. The LED will stay on green and the screen will flicker like it did before. Are we maybe looking at a broken T-con board? I imagine that it would be hard (if not impossible) to fix that on your own...?