Maxent MX42-x3 flickering rainbow display?

[tucocaps]

Hello,

I just picked up this heavy maxent plasma. My goal isn't to fix it, but to salvage parts, but I need to know what boards , if any, are bad on the unit.

Powers on, and primes OK. Then , at least several minutes later, the entire screen starts to flicker with a faint noise and a horizontal line "static" pattern. It was hard to get a picture, but I have attached what I could.

Thanks for any ideas.

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

Forgot to add that I can turn the set from on to standby using the front power button.

Should I be looking at the mainboard for this problem?

[tom66]

Re: Maxent MX42-x3 flickering rainbow display?

What is the panel in it? LG or Samsung or something else?

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

What is the panel in it? LG or Samsung or something else?

Good question. When I was researching parts for Maxent, I think LG came up. Any way I can check? Thanks!

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

I may be mistaken, but I think the flickering and horizontal rainbow static seems to go from less intense to more intense as the set warms up. About 5 mins in, it's just flickering a bit , with mostly black screen. Eventually, the whole screen fills. I think when I press the menu buttons, I can see a change in the flickering/static pattern.

[tom66]

Re: Maxent MX42-x3 flickering rainbow display?

You can check by opening the unit up, you will need to do that anyway to get the parts out.

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

You can check by opening the unit up, you will need to do that anyway to get the parts out.

Any idea where that brand is stamped on the panel? I don't recall seeing it on the other plasmas I was working on.

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

Well I did some research, and was surprised to find the panel is a Panasonic (Matsushita). There is a reference to this in an archive discussion at another forum. I wonder if I could've used this panel to "fix" my other broken 42 Panasonic plasma I just stripped of all parts

Anyway, that is the brand, and I do have the back off. Could this flickering be a bad connection of some sort? I haven't tried feeding the set with any video/audio yet, because I figured that would be impossible since I can get no actual display on the panel. Just black or flickering rainbow snow.

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

I believe the flickering is both display and backlight. When the room is dark, it looks like one of those scary movie tv scenes with random flickering against the wall.

[tom66]

Re: Maxent MX42-x3 flickering rainbow display?

Panasonic panels do have test patterns but AFAIK you have to connect it to a Panasonic main board to activate them. What you can try is pulling out the LVDS while it is running. If the image freezes there is a fair chance the main board is the cause of the fault. It is hard to be certain though. It will be main board or D board in my opinion.

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

LVDS? Not exactly sure where that is located. Here is a picture of the back.

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

It looks like the main board on this unit has had many "flickering" and line related problems in the past when the set was newer.

I think I found the LVDS if it is that small cable with the separate ground connection going to the mainboard. If so, unplugging it seemed to have no affect on the display.

I'd just like to narrow this down to the parts that are definitely "not broken" at this point, because I might try to sell some of these, or keep them on the shelf for other use.

[tom66]

Re: Maxent MX42-x3 flickering rainbow display?

This is the LVDS.

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

This is the LVDS.

Well, when I unplug that one, the screen goes from the flickering action back to just black, with a dim backlight.

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

Hey tom just saw you were on. any more ideas? thanks.

[tom66]

Re: Maxent MX42-x3 flickering rainbow display?

It sounds like a bad main board but it is not possible to rule out the other boards.
The SC, SS, SU, SD and P boards are all probably OK.
The D, C Panasonic boards, and OEM's main board is suspect.

Please note a plasma panel does not have a backlight, what you are seeing is known as the priming glow.

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

thanks again Tom66!

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

Oh, I forgot to ask you Tom. On the power supply board for this unit. Do you think it would be normal to hear a relay click when the unit is plugged in / powered on ? I've been wondering if that noise gets louder as the ps boards start to age.

[tom66]

Re: Maxent MX42-x3 flickering rainbow display?

Oh, I forgot to ask you Tom. On the power supply board for this unit. Do you think it would be normal to hear a relay click when the unit is plugged in / powered on ? I've been wondering if that noise gets louder as the ps boards start to age.

It's normal, and it can be very loud, which isn't indicative of a fault.

[tucocaps]

Re: Maxent MX42-x3 flickering rainbow display?

I guess I'm still confused about the "lettering" of these plasma boards. What are the "D" and "C" boards?