42" Samsung plasma acting strange

[ben7]

Uh oh!

Our TV just started displaying random colors and stuff and lines on the screen. I was like, oh NO, its dead!

I unhooked the HDMI and used the RCA video, and it is working now.

BUT, now there are bands of white haze slowly going up the screen. Could there be a bad capacitor in the power supply messing up the scan rate?

I tried restarting the cable box (DVR) and it didn't change anything. I might try using the DVD player tomorrow.

I will try to get the model for you later.

-Ben

[tom66]

Re: 42" Samsung plasma acting strange

Pics of fault, or it didn't happen! It does sound like a capacitor fault - as freezing pictures/graphical glitches are occasionally reported symptoms when caps go bad on Samsung TVs.

[ben7]

Re: 42" Samsung plasma acting strange

Pics of fault, or it didn't happen! It does sound like a capacitor fault - as freezing pictures/graphical glitches are occasionally reported symptoms when caps go bad on Samsung TVs.

Er, other family members are using the TV right now, I might be able to get pics in about 15min.

I'm guessing it is a badcap, b/c I didn't replace all the CrapXons (shame on me!) in the PSU when I had to fix it before ( failed mosfet ).

[ben7]

Re: 42" Samsung plasma acting strange

Ok, here are some pics.

I managed to pause a show in between the commercials, so the screen was black. You can see the white fuzzy stripe, and it just slowly climbs upwards.

I took two pics of the HDMI issue, one when the screen flashed pink, and another when it showed some random garbage.

Its almost like the video processor is crashing, and then showing junk on the screen.

Also note the burn-in on both sides of the screen

Sorry if the pics are a bit blurry, our living-room doesn't have much lighting in it, and its dark outside now. And to make it worse, the TV is very bright, so the camera has a hard time focusing.

[tom66]

Re: 42" Samsung plasma acting strange

Looks almost like a Y-buffer problem, but possibly bad caps too.

[ben7]

Re: 42" Samsung plasma acting strange

Looks almost like a Y-buffer problem

Aw, why?

I think the video processor keeps crashing, and then it display random junk.
It will flash random things on the screen when trying to receive an input signal from HDMI.

It works without the artifacts using the RCA input. But there is that stripe going up the screen. I'm thinking some 60hz ripple is causing the video processor to crash, and making the scrolling bar on the screen.

The model number is: HPT4254X/XAA

The thing is, this happened all of a sudden, so it might not be a badcap issue. Unless one went open circuit at once.

[crashp3]

Re: 42" Samsung plasma acting strange

Do you have pictures of the T-CON? This likely has diag jumpers to display test patterns with the mainboard out of the equation to determine if it's the video processor (on mainboard) crashing, or a buffer problem.

[ben7]

Re: 42" Samsung plasma acting strange

Do you have pictures of the T-CON? This likely has diag jumpers to display test patterns with the mainboard out of the equation to determine if it's the video processor (on mainboard) crashing, or a buffer problem.

Plasma Tv's don't have a T-con

[crashp3]

Re: 42" Samsung plasma acting strange

Plasma Tv's don't have a T-con

my apologies... the LOGIC/CTRL board.. and I just confirmed with the service manual for the set, it does have the 4pin diag header on the LOGIC/CTRL board.

[tom66]

Re: 42" Samsung plasma acting strange

Plasma Tv's don't have a T-con

Yes, they do. Sometimes called the logic board. But they also need a timing controller.

[ben7]

Re: 42" Samsung plasma acting strange

my apologies... the LOGIC/CTRL board.. and I just confirmed with the service manual for the set, it does have the 4pin diag header on the LOGIC/CTRL board.

Ah good, well I might be able to open it up later, we will be busy today, so if not then tomorrow I might be able to get it open.

Yes, they do. Sometimes called the logic board. But they also need a timing controller.

I will try it with the DVD player and see if it has the same problem.

[tom66]

Re: 42" Samsung plasma acting strange

The reason I said it looks like a Y-buffer issue is that graphical glitches such as repeating patterns can sometimes be caused by a bad Y-buffer. A Y-buffer is responsible for driving the whole line and with correct timing; if it gets confused you will get noise on the screen.

[ben7]

Re: 42" Samsung plasma acting strange

The reason I said it looks like a Y-buffer issue is that graphical glitches such as repeating patterns can sometimes be caused by a bad Y-buffer. A Y-buffer is responsible for driving the whole line and with correct timing; if it gets confused you will get noise on the screen.

Then why would it work ok (except for the white scrolling haze) on the RCA input? Would it be because of the resolution?

[tom66]

Re: 42" Samsung plasma acting strange

Then why would it work ok (except for the white scrolling haze) on the RCA input? Would it be because of the resolution?

Probably bad caps then or some other video controller issue.

[ben7]

Re: 42" Samsung plasma acting strange

Probably bad caps then or some other video controller issue.

Hopefully its not something expensive, it just started doing this all of a sudden, but no pops, or smells.

[ben7]

Re: 42" Samsung plasma acting strange

Well, what do ya know!

Its NOT the TV, its the fu&#*^! HDMI cable. We have bought cheap ones, and expensive ones, and after a year or two they break inside and we have to get a new one.

We were just about to take the TV off its mount and I did have it turned on to show everyone else what it was doing. I went to grab the HDMI cable and the picture went back to normal off a sudden! I wiggled the cable, and sure enough the picture flickered too. Damn crappy cables.

[tom66]

Re: 42" Samsung plasma acting strange

Some cheap cables are okay, others are poor. Currently using a cable bought for £1 with Full HD picture at 50Hz, no issue. HDMI, 1 metre. I find it hard to believe TBH; I suspect you have a cold joint on your main board and wiggling HDMI has fixed this.

[ben7]

Re: 42" Samsung plasma acting strange

Some cheap cables are okay, others are poor. Currently using a cable bought for £1 with Full HD picture at 50Hz, no issue. HDMI, 1 metre. I find it hard to believe TBH; I suspect you have a cold joint on your main board and wiggling HDMI has fixed this.

Its actually in the cable itself, I tried turning it around and it is at one particular end of the cable, it doesn't matter if it is plugged into the TV.

[tom66]

Re: 42" Samsung plasma acting strange

Its actually in the cable itself, I tried turning it around and it is at one particular end of the cable, it doesn't matter if it is plugged into the TV.

And this caused white haze on other inputs?

[ben7]

Re: 42" Samsung plasma acting strange

And this caused white haze on other inputs?

Nope, I don't know what is causing that, but it might have been like that for a while, its just barely noticeable.