Philips 75PFL5704/F7 A Video Issue

[Nicktronic]

Hey everybody, got a strange one here.

The TV will display the Home Screen, Menus, Netflix Home Screen, YouTube home screen with preview tiles, etc, without issue. As soon as I try to play video (streaming or from any of the HDMI inputs), all I get is audio and and blank screen. It's like the video is not being processed. So I ordered a replacement main board. I can now play video from streaming sources but the video from HDMI sources is all green (kinda like photo negatives but all green) and the audio does not work. Is it possible the main board I ordered is also failing?? I can't see the T-Con being the problem, as it works showing menus, tiles and streaming video. I have no idea where to go from here. Hope somebody has some pointers...

Pictures attached.

[EazyBone]

Re: Philips 75PFL5704/F7 A Video Issue

What happens when you stick the old main board back in? Problem back? There's always a possibility main board ordered is bad. They come from broken used tvs generally.

[Nicktronic]

Re: Philips 75PFL5704/F7 A Video Issue

What happens when you stick the old main board back in? Problem back? There's always a possibility main board ordered is bad. They come from broken used tvs generally.

Yeah, exactly, the same symptoms come back with the old board.

Of note, pretty loud buzz coming from both the main board (original) and the T-Con board. When i put the new main board in, no buzz, but the T-Con continues to buzz. Thoughts?

[EazyBone]

Re: Philips 75PFL5704/F7 A Video Issue

So you put original board back in and green goes away is what I meant to ask?

So with new board screen is green but everything works normal.

With old board screen is not green but streaming pauses.

I mean sounds like you got a bad board from whomever. I don't actually have any info on this problem and can't be much help but If original board is fine with color and replacement isn't I'd assume replacement is bad. Maybe you can use search functions to find green picture or something

[Nicktronic]

Re: Philips 75PFL5704/F7 A Video Issue

So you put original board back in and green goes away is what I meant to ask?

So with new board screen is green but everything works normal.

With old board screen is not green but streaming pauses.

I mean sounds like you got a bad board from whomever. I don't actually have any info on this problem and can't be much help but If original board is fine with color and replacement isn't I'd assume replacement is bad. Maybe you can use search functions to find green picture or something

New board - Good menus, static images, etc. Green screen during HDMI video AND no audio. Streaming video AND audio work find.

Old board - Good menus, static images, etc. No video playback with HDMI AND streaming (black screen), but audio is good.

[EazyBone]

Re: Philips 75PFL5704/F7 A Video Issue

Odd. You tried different HDMI cord I assume?

I mean if you can stream video with audio then I can't see how a Tcon would be your issue. It sounds like something is wrong again with the main board or the cord going to it. If consider hooking up that device to another TV to test it also just to see it's not the devices end. But just by logic it would indicate a bad main board if everything else is working fine. Usually the pros don't comment on these cheap TVs lol but id try new cord/other tv first to rule all that out.

[diif]

Re: Philips 75PFL5704/F7 A Video Issue

I suspect the BGA under the main processor is at fault on the mainboard.

[Nicktronic]

Re: Philips 75PFL5704/F7 A Video Issue

Odd. You tried different HDMI cord I assume?

I mean if you can stream video with audio then I can't see how a Tcon would be your issue. It sounds like something is wrong again with the main board or the cord going to it. If consider hooking up that device to another TV to test it also just to see it's not the devices end. But just by logic it would indicate a bad main board if everything else is working fine. Usually the pros don't comment on these cheap TVs lol but id try new cord/other tv first to rule all that out.

I agree, can't see the T-Con being the issue at all. Tried a different input device and this time got good video on all three HDMI ports but but the green screen would flicker in and out periodically. I guess I gotta look at the ribbon cable between the Main Board and the T-Con, and then possibly the new main board being faulty.

As diff mentioned, if BGA is the problem, I could do a rough test on the old board by cooking it for 10 minutes in the oven just to see.... (I know it's a hack repair, but don't care so much on the old board!)

[diif]

Re: Philips 75PFL5704/F7 A Video Issue

You want it to be around 5-6 minutes in total and ensure it's hot enough 218c/424f to melt the solder. Remove the heatsink first and ideally you want to use some flux.

[Nicktronic]

Re: Philips 75PFL5704/F7 A Video Issue

You want it to be around 5-6 minutes in total and ensure it's hot enough 218c/424f to melt the solder. Remove the heatsink first and ideally you want to use some flux.

So, I did what you said and no change in operation unfortunately. Is 6 minutes @ 425F enough to melt the solder though? I did use flux and removed the heatsink. This is blowing my mind that both boards operate "kinda" the same way. Possible both new and old main board processors are bad....