CurtPalme.com Home Theater Forum

[Elaine Benes]

Hey, does anyone have any experience with a Marquee that has geometry "hold" issues ?

I've had quite a few Marquee's, and they've all been pretty much rock steady when set. They keep their settings and nothing seems to knock them off, but this one I have now is different, and I'm not sure where to start.

The geometry settings can "lose" their position, but then when you change it a single click, they'll bounce back into the position originally set . For instance, I don't set my finished screen size till I have keystone and pincushion ironed out, then the picture phased properly, then I tweak size to make circles round. When I do this, suddenly the pincushion will "pop" back to default but the number setting for it remains the same. If I access the Pincushion control, and move it a single click, it "pops" back to where it should be according to the numbered range.

Has anyone seen this before ?

I checked that all the IC's from the convergence board were held tightly in place on the heatsink, all are snugly snapped in place.

As an aside, this Marquee seems to have very drifty convergence. My ancient 8000 would stay virtually perfectly converged for months at a time, whereas this 8500 drifts in hours, and by quite a bit.

There seems to be a lot of static discharge at power down too. I didn't have any of that with the old Marquee, maybe because I did the asphalt impregnated wire loom mod to all the HV leads ?

Any speculation as to what I can do to rectify this situation would be appreciated. Thanks.

[Curt Palme]

Check the CRT ground leads on the neck board, I had one set come in missing that ground lead. Reseat all chips on the CLM. Reseat and clean the HDM module contacts. Check for glycol leakage on the system control chip on the backplane.

Maybe it's jealous and is trying to tell you you have too many MArquees?

[Curt Palme]

Check the CRT ground leads on the neck board, I had one set come in missing that ground lead. Reseat all chips on the CLM. Reseat and clean the HDM module contacts. Check for glycol leakage on the system control chip on the backplane.

Maybe it's jealous and is trying to tell you you have too many MArquees?

[Tim in Phoenix]

Hello

There is a bulletin out for Marquees, the problem is called "snap" and has to do with noise garbling the settings. Try replacing R35 on the control board with a 3300 ohm surface mount resistor; it is in the back left portion of the board.


.

[Nashou66]

It's most likely what Tim said, but curt s suggestion is valid as well and when looking at the HDM you should replace C50 and also check the solder points for the transistors and Mosfetts on the heat sink, id resolder them and the solder points for the relays. I found its better to do the convergence of the grid before doing any keystoning and other geometry functions. then do the geometry stuff and go back to convergence again. less chance of banding this way also and the convergence hold better for longer periods.

Athanasios

[Elaine Benes]

Thanks very much for the replies. I'd already done the CLM cleaning and re-seating, and all neckboards have good grounding straps. I'll have to get someone to do the CLM resistor change for me, I'm no tech... And get to the HDM cleaning/re-seating.

I think I can rule out jealousy, as I only ever have one Marquee at a time(in the same room, anyway...).

BTW, what do you mean by "you should replace C50 nd " ??

Do you mean I should replace resistor C50 the same as the one Tim pointed out to replace, or something else that I'm not getting ?

[Tom.W]

Looks like that should have been the word AND. Must be a typo...

[Nashou66]

[PaulB]

For C50 replacement , use a 220uf 160v 105 degree capacitor - http://www.mouser.com/Search/ProductDetail.aspx?qs=JeGW9eJcCSdVk%2fkJhRuYKg%3d%3d

There should be no need to replace any resistors or Mosfetts etc unless they look damaged in any way. As Athanasios says, also check the soldering joints on the resistors and Mosfetts attached to the big heatsink, (looking for bad joints, cracks especially) - use a bright light and a magnifying glass. Re-flowing the solder (ie melting it with a soldering iron so that its liquid for a second or two) will likely cure any defects in soldering.

For the Snap fix, use this http://www.mouser.com/Search/ProductDetail.aspx?R=CRCW12063K30JNEBvirtualkey61300000virtualkey71-CRCW12063K30JNEB

With Athanasios kind help and encouragment, I went from an absolute soldering disaster to having reasonable basic skills sufficent to make most mods to the Marquee. Biggest problem I have is actually understanding what needs to be done and what the actual parts are that I need.

Most of what Athanasios, Tim and 1031 say is double dutch to me but if you can eek out the part number you need to use from them it begins to make sense! If you look at most of my posts I'm asking "whats the part number for xxxxx", thats because I've no idea what they are saying but I'm willing to try to solder whatever part they say into whatever location its needed in !

Get yourself a good temp controlled iron, practice and then get modding You'll get there, just takes a few hours practicing on an old graphics card or something.

Some soldering advice - good iron as stated above. I use pre-tinned tips (saves a lot of hassle). I use tips of a .5mm and 1mm for majority of work. Use de-soldering wick and an electronic desoldering pump - they both come in very handy. A magnifying glass and and desk light is good. A soldering tool-kit like this http://www.maplin.co.uk/Module.aspx?ModuleNo=34099&criteria=soldering%20tools&doy=7m5 comes in handy. Small wire cutters. Oh and most important, plenty of patience and a willingness to try Total cost will be around what, 150 bucks or so? But its worth the effort, believe me, its worth it.


Paul

[Elaine Benes]

Thanks very much for the part numbers and advice on soldering. I doubt I'll be doing any of my own soldering any time soon though, I don't have even the most rudimentary understanding of it. I'm not the kind of person who can learn a skill with only reading about it.
I've been an ardent golfer for over a decade now, and I still haven't even come close to mastering that skill. I have read over 20 good books on how to, but still struggle with it. Soldering seems even more difficult to me.

[PaulB]

Nah, its easier than you think, its like golf, you just need the right tools (club) for the right job (distance)!

If you have a friend that can do the soldering then great, if you haven't then its worth a try at least. Took me all of a week to go from "whats a soldering iron?" to "man, I did it!!"

Now, golf looks difficult to me! My partner plays and she makes it look easy but I'm fracked if I can hit a ball more than a few yards much to her amusement (if I can hit the ball at all that is), absolutely useless


Some starters (all you need to know really);

http://www.kpsec.freeuk.com/solder.htm

http://www.kingbass.com/soldering101.html

http://www.bscra.fsnet.co.uk/Soldering.html

http://www.instructables.com/id/How-to-solder/

http://www.solder.net/technical/tips.asp

Any ONE of these will get you going. I looked at them all (plus a couple of others) and now realise that once you get the basics right its not difficult at all - its like riding a bike, once you grasp the concept its easy as pie but getting to that point can appear daunting! You clearly know your way round a Marquee which puts you a good couple of steps in front of me when I first started soldering, its worth a punt, 20 bucks for a half decent iron and some solder and see how you get on - just make sure you tin the tips and keep them shiny by wiping them on the wet sponge - thats it, thats solderings big secret!


Paul

[Elaine Benes]

Ok, so I got a local tech to replace the surface mount resistor, and it still "snap"s.

By the technical bulletins description, this is exactly my problem, but the resistor change didn't fix it. My CLM is the exact issue described in the bulletin, is there any more to be done, or do I need to look for a replacement CLM ?

I didn't buy a part from Mauser or anywhere else, I just asked the tech to replace it if he had the part. I have no expertise to check his work, nor if he used the correct part, I just supplied him with a copy of the technical bulletin and the Mauser part number...

BTW, I've changed out the HDM too, with that not helping or hurting the situation in any way...

[Elaine Benes]

Does anyone have any more suggestions about this ??

I've tried another, newer CLM in my projector and I definitely still have the issue.

On a side note, it seems to be lessened with my original CLM installed, but still present.

Can I change out my HDM or VDM or something to get rid of this jumping in basic settings ???

[Nashou66]

Not to question your set up skills, but it might be something as simple as that. You might be putting unnecessary strain on the geometry circuits.
did you do convergence first then go into the other geometry controls? I found doing it this way made my 8500 more stable.

On the issue it might be a weak board somewhere, you said pincushion snaps out of position I was looking over the service manual. These waveforms for key-pin are generated on the VDM and sent to the HDm where they pass through the scan regulator on to the Modulator of the HDM. The scan regulator allows a 10% head room for the key&pin waveforms.
If one of these circuits has something altering those wave forms or not holding them stable, then this would be the cause of the jumping in and out of place. I'd start with swapping out the HDM first as its the easier of the two boards. Probably one of the caps that help keep the waveform stable has weakened somewhere in one of the boards, Id bet the HDM.

Athanasios
Athanasios

[Elaine Benes]

I'll try a third HDM, see if that helps.

The snapping out of place occurs most notably on pincushion, L/R skew, but also on Red and Blue vertical size, and it will happen when setting red and blue vertical size as the first or second adjustment made after a complete initialization.

I have tried doing the convergence first, then the geometry as you suggested, the snap still occurs. If I make adjustments really slowly, pausing between key pushes, it *seems* to be less likely to occur, but can also pop if I make some last little geometry tweaks after everything is pretty much done.

I find that the geometry generally needs a tiny bit of tweaking to get a perfectly square/level image on the actual video image if you've done the setup from the internally generated patterns. This is pretty much my last step after everything else has been done. I follow the "HELP" guidelines for setup otherwise.

[macgyver655]

I've read over this post a few times and find very little concern on the convergence amp other then check that the ic's were tight. Have you tried swapping this board or am I missing something here.

[Elaine Benes]

[macgyver655]

The convergence amp is connected directly to the convergence coils on the tubes. All the wave forms are brought together and go through the amp to the coils which adjust the grid. Its the last stage in the process. I'll agree there are many things that must happen to adjust geometry but it sounds like you've tried most of the others so this very important one is left. I'm not convinced it is there but should be a try. Your adjustment should by no means be so sensitive.

[Nashou66]

Most of the waveforms for those key,skew for left and right are generated on the VDM and sent to the HDM
that is why i said to check that first.
Have you tried cleaning the contacts/connectors that go from the CVA and VDM to the Mother board?
I am wondering if these might be a little oxidized and not keeping a stable signal from the CLM and to the HDM.

Also how do the internal grids look after a complete re-initialization , are the level? if not this could cause
the snap from working the HDM circuits a bit harder to keep the pin and key correct on an unlevel grid
for one of the tubes.

Athanasios

[Elaine Benes]

The internal patterns were not very level upon a re-initialization, initially, but I've since leveled them quite a bit better by physically re-orienting the scan yokes. I've not glued them down yet, as I wanted to be sure I had this snap problem cleared up first....

Hmmm...looks like I shouldn't have gotten rid of that rear heat sink with the accompanying boards that I kept for so long then sold in the belief I'd never need it...hindsight...

[Nashou66]

I wonder since they are not glued down yet that they might have moved back from the bell or shifted as well. I would make sure they are level and as far up to the bell housing and glue them. No need to keep them unglued once they are level.

Athanasios