Samsung LN46A650 with suspected video processor issues

[Wizard]

Re: Samsung LN46A650 with suspected video processor issues

I have LN40A450 on test with similar issue like yours but I have not seen the symptom. Can you describe what picture looks like? In detail as best as you can.

Cheers, Wizard

[hardwareguy]

Re: Samsung LN46A650 with suspected video processor issues

The effect is random.

Sometimes its total picture corruption....nothing but colored lines on the entire screen. This is sometimes accompanied by a loud tone from the speakers. When this happens, the controls will be non responsive.

Other times TV operation continues but one or more white vertical lines will be present. They sometimes flicker and shift position. The TV image may freeze shortly after the lines appear.

Other times, especially with the 1 or 2 white line problem, the TV may spontaneously turn off and back on.

[MixMasta]

Re: Samsung LN46A650 with suspected video processor issues

Crazy idea... but do you have the latest firmware flashed on this lcd tv?

[hardwareguy]

Re: Samsung LN46A650 with suspected video processor issues

Firmware wont cause the issue Im seeing...this is strictly a hardware fault.

Besides...if it crashes while flashing, the TV processor board is bricked!

[kc8adu]

Re: Samsung LN46A650 with suspected video processor issues

like flashing a bios on a mobo that has bad caps?i see that often.
since you see ripple on the supply only when it acts up and you replaced caps and rectifiers look for small linear regulators with open caps nearby.they can oscilate when input or output caps open.

[MixMasta]

Re: Samsung LN46A650 with suspected video processor issues

You're right, this firmware update sounds nothing like any of your problems:

* This firmware will correct the following phenomenons some units may experience.

-. Intermittent audio drop out

-. AMP(Auto Motion Plus) stuck
-. do not memorize ''SRS'' setting
-. The audio comes from speaker when loading the CD(Game title)
though ''Internal Mute'' is on(speaker is off)
-. Intermittent shut off and on

* The firmware will be updated to the following version. ''ver 2007.0''


* Please be sure to read the instruction before beginning the update process

[hardwareguy]

Re: Samsung LN46A650 with suspected video processor issues

This has to be the most troublesome set to troubleshoot....it hasn't failed in two months.

If we cant observe the fault, we cant fix it. I doubt its magically fixed...it WILL die again eventually.

[tmwalsh]

Re: Samsung LN46A650 with suspected video processor issues

Sounds temperature sensitive, no? Is possilbe the shields have been left off the back of the monster, thus keeping the temp lower?
From all the description read, the main suspect in my mind is still the power supply. The machine going 'nutz' is a symptom of losing power and then getting it back quickly to me. If power was applied and then removed and then re-applied, any computer [which this has more or less] can get lost, can jump to addresses that are bogus, can use data as program, the possibilities are endless.
tom

[freelander]

Re: Samsung LN46A650 with suspected video processor issues

There is a second thread about this TV with a lot of law suit talk so I thought I would pick up this thread instead. I picked one of these TVs up super cheap and it shows lines that seem to only happen when there is red on the screen. Blacks come out perfect. The tv is apart and everything looks perfect. It was suggested that this was the TCON board but I don't have experience with big tv's and I don't have a scope. Can someone point me in the right direction?

[Wizard]

Re: Samsung LN46A650 with suspected video processor issues

This either points to T-CON or panel.

PS: can't scope high speed signals that is used on LCD panels.

Cheers, Wizard

[freelander]

Re: Samsung LN46A650 with suspected video processor issues

thanks Wizard. Is there anything that I should check with a multi-meter on the T-Con...it seems to be all solid state.

[Wizard]

Re: Samsung LN46A650 with suspected video processor issues

Again, cannot do this with meter as this requires experience to know what to expect good voltages. Replace this board to test is prudent.

Cheers, Wizard

[freelander]

Re: Samsung LN46A650 with suspected video processor issues

ok...so I have replaced the main controller board and the TCON board with the same results. The lines follow changes in the signal. Some areas of the display are perfect and others have these streaky lines in them. They are somewhat random at least as much as location goes so this doesn't appear to be a board or display problem from what I can tell.

I can order new caps for the power board but before I go through that exercise could bad / marginal caps affect the board like this? The picture in post 29 is a good representation of what happens.

[freelander]

Re: Samsung LN46A650 with suspected video processor issues

I wanted to post again since I am hoping that there is some advice or experience that can point me in the right direction. This TV has the TCON board, the main IO board and the power board. Based on advice from here, I have replaced the TCON and main IO boards as well as replacing the caps with new Panasonic low ESR ones just to be safe (no signs of issues).

The TV is essentially the same where in many images lines will appear and seems to focus on red images for the most part. I can get images that look perfect and I can also change the effect by selecting different display modes. The following are the same image with changing modes...the movie mode is the blurry picture but it also minimizes the effect most.

I have gone in to the service menu and reset to factory defaults but I haven't adjusted anything else. It seems like the TV is capable of working properly so I am stumped by what to do next...suggestions?

[Village Electronics]

Re: Samsung LN46A650 with suspected video processor issues

I wanted to post again since I am hoping that there is some advice or experience that can point me in the right direction. This TV has the TCON board, the main IO board and the power board. Based on advice from here, I have replaced the TCON and main IO boards as well as replacing the caps with new Panasonic low ESR ones just to be safe (no signs of issues).

I think you have a bad panel. I have seen this before on certain JVC and Sony models.

[freelander]

Re: Samsung LN46A650 with suspected video processor issues

OK...well that kinda sucks and isn't really what I was hoping to hear. Just so that I understand, is this a component or chip on the panel that is bad and it is too difficult to trace down so that makes that panel bad?!?

[Village Electronics]

Re: Samsung LN46A650 with suspected video processor issues

OK...well that kinda sucks and isn't really what I was hoping to hear. Just so that I understand, is this a component or chip on the panel that is bad and it is too difficult to trace down so that makes that panel bad?!?

I don't know which part of the panel is bad. If you ever get the chance to take one apart you will get the idea.

[Styles]

Re: Samsung LN46A650 with suspected video processor issues

[QUOTE=freelander;181296]I wanted to post again since I am hoping that there is some advice or experience that can point me in the right direction. This TV has the TCON board, the main IO board and the power board. Based on advice from here, I have replaced the TCON and main IO boards as well as replacing the caps with new Panasonic low ESR ones just to be safe (no signs of issues).

I have the same problem same model did you ever find a fix was going to do all that but I noticed ribbon on the tcon connecting to panel has some damage to it hope you can help thanks

[freelander]

Re: Samsung LN46A650 with suspected video processor issues

I went through the same steps replacing the TCON and main IO board as well as re-capping the whole thing...no effect. The issue is with the panel. I sold it to a guy on Kijiji that said he knew how to fix it. I said good luck to him and moved on.