CurtPalme.com Home Theater Forum

[Ben851]

Howdy Fellas,

My Marquee has started developing an odd problem that I was hoping someone could shed some light on... The blue tube has developed a severe flicker problem. At first I was sure it was my cable as I had mangled my HDMI cable pretty bad, but then I noticed the same issue on my xbox 360 which is input via RGB. I've established that it happens on all 3 of these video chains:

PS3 - Marquee via Moome HDMI Card
PS3 - Marquee via Moome DVI Card
Xbox 360 - Marquee via RGB

The flickering seems odd to me as instead of dimming the picture in the noisy areas it actually looks as though the G2 is increasing. I've also noticed that the problem gets better as the set warms up. Instead of going away it gradually turns into a streaking problem.

I've tried reseating the VIM but that didn't do anything (on a side note - I noticed that my VIM ever so slightly sags in the middle - anyone else notice this?)

After reseating the VIM for the third time, my convergence went all wacky on me - not sure if this was a coincidence or not... But the red convergence on the very top of the screen about a foot right of center went to its extreme up position, and the same happened to the blue but at the very bottom of the screen about a foot left of center and it went to its extreme down position... Weird stuff...

Any thoughts?

[Nashou66]

Hi Ben, first make sure the RGB cables are all seated well in the VIM and then go to each neck board and make sure you video,G2 connectors, the one going to the board and the one from the board to the tube are connected well. make sure yo connect the whit G2 cable to the correct pin!! Use another tube for refrence.

the pull the CLM and clean all removable chips pins, or temporarily put the CLM on a flat surface and press down on those chips.

You might have lost convergence if those chips are not making good contact. but look for some Caig Cleaner at radio shack to clean all the pins on all boards in your set and the video cables. remove all daughter boards and removable chips and clean them with the Caig cleaner. While at radio shack buy a Chip puller to remove the chips. Pay close attention to the orientation of each chip and do one at a tim as to not mix them up.


Oh and there are two board on the CLM remove them and clean those contacts too and any removable chip especially U7 on the Deflection processor board.

then put it all together and report back.

Athanasios

[Ben851]

Thanks Nashou, I'll take a look tonight!

[Curt Palme]

It could be a few things. Before you do what Nashou says, simply put up the test pattern to see if those flicker as well. If so, it's an internal issue with the set, if they are solid, it could be the VIM, but can also be a bad cable external to the set.

[Curt Palme]

It could be a few things. Before you do what Nashou says, simply put up the test pattern to see if those flicker as well. If so, it's an internal issue with the set, if they are solid, it could be the VIM, but can also be a bad cable external to the set.

[Ben851]

Thanks Curt,

I have to think that I've already ruled out a bad cable - I find it hard to believe that 3 different cables that have been reliable in the past all developed the same problem instantaneously... I've tested with a monoprice 20ft HDMI cable, a 15ft generic HDMI-DVI cable, and a plain old RGBHV breakout cable - the problem remains with all 3...

[Curt Palme]

OK, so now concentrate on the neck boards on the back of the tubes. Swap over the mini RCA video feeds between the green and blue tubes, ditto for the black G2 lead. See if switching one or the other transfers the flicker to the green tube.

[Curt Palme]

OK, so now concentrate on the neck boards on the back of the tubes. Swap over the mini RCA video feeds between the green and blue tubes, ditto for the black G2 lead. See if switching one or the other transfers the flicker to the green tube.

[cmjohnson]

I'm thinking of the common problem with burned resistor connections to the two big power resistors on the neck board. That's usually caused by leakage from caps going bad.

I'd say that there's a good chance that your neck boards need to be recapped and the resistor connections resoldered.


CJ

[Nashou66]

Curts right, thats why i said check the cables on the VNB's(neck boards) could be something as simple as the video cable.

But a routine cleaning of the chips every year should be done.

And while your looking at the video cables and swaping them do look at the solder joints of the two big orange/brown resistors like Chris mentioned, it could be that as well, but i always track down issue with the basic cleaning of contacts and chips. then move on the bad component possibilities.


Athanasios

[Ben851]

Sounds good guys - I'll give the set a once over tonight and post back tomorrow.

[Curt Palme]

[Curt Palme]

[draganm]

[Nashou66]

[Ben851]

Well I opened her up last night, pulled out the CLM and made sure that any ICs were fitted properly, same goes for the two daughter boards.. that had no effect. I took the shielding off the blue neckboard and inspected it, the two big assed resistors look fine - I reseated the G2 cable, that had no effect. I didn't get to actually swapping cables between neck boards though.. Two questions though:

1) I noticed that the neck board on the blue has considerable wiggle play on it - as in if I pushed in at the top of the card, the bottom would pop out about 5mm.. I tried to seat it as evenly as possible but the wiggle play is still there.. is this normal?

2) Those mini-rca connectors - do they just pop off? They seem to be on there pretty tight and I couldn't find a good grip on it to yank it off...

Bonus question - is there anything on the neckboard I should steer clear of touching in terms of HV?

[Nashou66]

Don't touch anything on the VNB, some high voltage G2 lines are there. Some movement is normal, not sure what you mean but never try to move wires on the set while its fired up, you can hurt the PJ and more important yourself. Move wires and wiggle them when the set is off then turn it on, a arc or an accidental disconnect of any of the cables can spot burn a tube fast.

So next thing to do is remove the VNB from the tube that is showing the problem and put it on another tube, pay attention tot he G2 whit wire on the tube pins, make sure it goes to the correct pin. or you can burn the tube, if for some reason you do connect it wrong and you see the rube go really bright, pull connector P14 on the mother board near the back of the blue tube. What i do when testing things is i tie a string to the wires on the P14 and have it ready if i need to pull it in a hurry. One pulled you can shut down the set safely with no spot burn.

Athanasios

[1031]

[Ben851]

Alright, I swapped the Green and Blue neckboards, problem stays with the blue tube... though I also noticed that the same issue seems to be happening on a way lesser degree on the red and green. I dicked around with my setup a bit to make sure that I wasn't stressing any of the convergence controls, and while this had no effect it did allow me to confirm that over time as the system warms up, the flickering stabilizes but I'm still left with pretty severe streaking (only on blue).

Any more thoughts anyone?

[draganm]

[Ben851]

Forgot to mention that I had swapped the Blue and Green mini-rca's on the VIM as well... no dice. I double checked and yes it occurs on the test patterns as well. Also, it happens IMMEDIATELY after the tubes get powered up - even before the source has been locked in/displayed. The other two tubes are dark while this happens.. I'm in the process of uploading a video that documents the whole issue - but my internet connection is brutal (live out in the sticks) so it probably won't be up until tomorrow.

Is it possible that something is messed up on the tube itself? Would this be an indication of improper filament voltage? Or perhaps there's some guck on my cathode?

Thanks
Ben

[Nashou66]

If its crud on the guns it usually does not flicker you hear more of a snapping sound. But you said your seeing it on all tubes to some extent. this leads to some other Problem. lets break it down to the board level with boards you can disconnect and still run the set.

Also what direction is the streaking vertical or horizontal?

1st try the Astig amp Board (SAB) by removing all connectors and turning on the unit, and replace one by one checking each time. If no change continue.

2nd try the Convergence amp (CVA) remove those cables all together and check with all removed, then repeat the process as in the 1st test

3rd if you have a Contrast Modulation Board (CMM) check by pressing * on the remote, it will tell you waht boards or options are on your PJ. You press * repeatedly to cycle to the next menu. if you have one remove it, it is located behind the plate above the CLM. If no change move on.

4th, the Focus board, between the red and green tubes, remove them all and test again one by one.

5th, Now the next test doesn't always work on all marquees as it depends on the VIM and other things, you can remove the black umbilical cord to the VNB's and the set should run for a minute before it shuts down, it still might be a VNB's spot kill circuit trying to shut down the HV or Blank out the Video(flicker).


if none of that fixes it then try cleaning the contacts on the daughter board of the HDM.

Also i know you pressed down on the Ic chips on the CLM and DPB but they really should be cleaned with a tooth brush and some de-Oxit.

let us know what you find.

Athanasios

[Ben851]

Thanks Athanasios - I'll take a look at that stuff tonight.. Here's the video that shows the problem.. It doesn't show the streaking very well but you can see it very slightly when I pull up the contrast box.. Streaking is horizontal...

EDIT: Duh I should probably post the link eh?
http://www.youtube.com/watch?v=CLT8Fwv3_LA