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wadde
Joined: 19 Jan 2010
Posts: 27
Location: Sweden
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| Posted: Sun Jan 24, 2010 1:50 am Post subject: Horizontal "shadows" in green tube, marquee 8500 |
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Just got my 4000hrs 500$(!) marquee 8500 out of the trunk and did a quick-sloppy-setup on a table.
And all was lovley much better and sharper than my old ecp exept for an anoying issue, shorlty explained:
Shadows extending to the left from bright spots in the green tube. No tendency at all in the other tubes.
And this is not from externals source either, moving around the convergence "square" makes some shadows going to the left, while only internal sync generator feeding.
Haven't got mutch time yet to rip check out all the cards and their various connectors, but will go over and clean out as much as possible tomorow.
I will try to get a shoot with tha camera and posing it here soon too.
Does anyone have any clue ? Maybe you guys familiar with the forum search-function can point me 
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Sun Jan 24, 2010 4:29 am Post subject: |
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the Green VNB, like the tube, works a lot harder than the other 2 tubes/cards.Either replace or hire someone to replace these parts and -re-solder
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cmjohnson
Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s
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| Posted: Sun Jan 24, 2010 4:41 am Post subject: |
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I was thinking about that, how the improvements listed there can improve color saturation, and it hit me: Improved linearity of the amplifier. The weak caps and questionable resistor connections can't do anything good for the amplifier's linearity.
I'm now wondering how easy or difficult it would be to actually test the linearity of the VNBs before and after the mods and get some
hard data on how cap changes have an effect on linearity.
Tse has probably already done it.
CJ
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wadde
Joined: 19 Jan 2010
Posts: 27
Location: Sweden
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| Posted: Sun Jan 24, 2010 5:40 am Post subject: |
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Oh thanks a lot for you guys helping out in this !
I just did some digging at my neckboards. And i found this out:
*The caps (which i just read about in the mike.p. maintenance page, good stuff) seems to be replaced and joints on resistors looking nice.
BUT the one back @ green tube has some small caps soldered onto and around U4, U1 and U3. Furthermore it is labeled 50-2013-05P as opposed to the others named 50-2038-01P.
*The blue neckboard had old caps at c1 & c26 plus the not so good-looking joints at corresponding resistors, and i had some real troubble geting any focus on blue.
Does the old caps relate to focusing problems too ?
| Nashou66 wrote: | Hi ! And welcome to the forum , It sounds like streaking, a worn out neck card is most likely the problem.
Swap neck boards and see if the problem follows, use the blue card as it's easier to see on the blue.
Nashou |
Thank you  This place really is friendly and invalueable for info.
But when i saw the green neck-board looking "modded" with caps and some other components in different places i hesistated on swapping them over to find out the streaking-problem.
What i understand from Mike Parkers bit "The 'blue' caps are on the early version boards only" it could be stock ? But the numbers on the boards make litle sense to me, speaking of early model.
But over here the clock is 6.50 in the morning, so i'm not at my brightest right now.
Some fresh caps are ordered anyways, but how should i do with the different green VNB ?
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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wadde
Joined: 19 Jan 2010
Posts: 27
Location: Sweden
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| Posted: Sun Jan 24, 2010 6:54 am Post subject: |
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| Nashou66 wrote: | Looks like you have the old style VNB on the green from a M8000 chassis, doest it have two small metal can transistors compared to the other boards that have surface mount transistors?. you can get them to not streak but it be best to find a newer style board.
Athanasios |
Yes, now at a closer look i saw the can-transistors,
And in this crappy pic i just shot, you see the extra soldered on caps. Resembles some mod for the old cards?
I'm putting Curt on sending me a newer board anyhow i guess.
And this is fun, i'm learning alot Once more, thank you guys.
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Sun Jan 24, 2010 7:12 pm Post subject: |
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| wadde wrote: | | And in this crappy pic i just shot, you see the extra soldered on caps. Resembles some mod for the old cards?. |
no not mod's, hand soldered fix from the factory. That's a very, very old card, from a 1993 Marquee 8000. It's useless really and good only for emergency testing/troubleshooting.
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wadde
Joined: 19 Jan 2010
Posts: 27
Location: Sweden
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| Posted: Sun Jan 24, 2010 7:18 pm Post subject: |
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| draganm wrote: | | wadde wrote: | | And in this crappy pic i just shot, you see the extra soldered on caps. Resembles some mod for the old cards?. |
no not mod's, hand soldered fix from the factory. That's a very, very old card, from a 1993 Marquee 8000. It's useless really and good only for emergency testing/troubleshooting. |
Oh i see. No wonder its trouble then. Out of the set she goes !
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cmjohnson
Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s
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| Posted: Sun Jan 24, 2010 7:26 pm Post subject: |
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Can anyone confirm that the Marquee neck card for the green tube is really any different from the cards for the red and blue tubes?
I've certainly never seen any difference. Identical cards have been in every unmolested Marquee I've seen so far.
CJ
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Tim in Phoenix
Joined: 21 Oct 2006
Posts: 4409
Location: Phoenix
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| Posted: Sun Jan 24, 2010 7:59 pm Post subject: |
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| cmjohnson wrote: | Can anyone confirm that the Marquee neck card for the green tube is really any different from the cards for the red and blue tubes?
I've certainly never seen any difference. Identical cards have been in every unmolested Marquee I've seen so far.
CJ |
Guys!
Only one part number for M8110, M8500 and only one part number for M9500 and Ultra until complete redesign a year or two ago.
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wadde
Joined: 19 Jan 2010
Posts: 27
Location: Sweden
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| Posted: Mon Jan 25, 2010 9:18 am Post subject: |
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And we are still learning
By the way, my focus trouble on blue crt was casued by another intresting thing. The defletction yoke was lose, someone has done a poor job gluing it to the tube. It had gone a bit back and was "hanging" more on the neck.
What i understand its important to have it as tight forward as possible. Time to bring out the melt-glue.
So now i just simply have to learn alingning all the yokes and magnets
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Mon Jan 25, 2010 6:08 pm Post subject: |
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| wadde wrote: | And we are still learning
By the way, my focus trouble on blue crt was casued by another intresting thing. The defletction yoke was lose, someone has done a poor job gluing it to the tube. It had gone a bit back and was "hanging" more on the neck.
What i understand its important to have it as tight forward as possible. |
the sweep yoke is supposed to slip-fit and socket into the convergence yoke directly behind it. The clamp on the convergence yoke then keeps both yokes tight up against the bell of the tube. If you do this then glue isn't really necessary IMO.
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wadde
Joined: 19 Jan 2010
Posts: 27
Location: Sweden
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| Posted: Mon Jan 25, 2010 6:24 pm Post subject: |
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Yup Good stuff right there, grabbed the pdf and all
| draganm wrote: | | the sweep yoke is supposed to slip-fit and socket into the convergence yoke directly behind it. The clamp on the convergence yoke then keeps both yokes tight up against the bell of the tube. If you do this then glue isn't really necessary IMO. |
Only problem for me was that someone didnt get them tight at all. I did consider not gluing the deflection yoke at all, so your on to something there. Maybe just a litle blip of glue....
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Mon Jan 25, 2010 7:05 pm Post subject: |
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| wadde wrote: | | Maybe just a litle blip of glue.... |
yeah that certainly wouldn't hurt after getting the yokes on correctly. Just don't drown the yokes with a full stick of glue like the factory did, no reason for it.
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wadde
Joined: 19 Jan 2010
Posts: 27
Location: Sweden
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| Posted: Mon Jan 25, 2010 10:52 pm Post subject: |
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| draganm wrote: | | Just don't drown the yokes with a full stick of glue like the factory did, no reason for it. |
My thought exactly.
So, redoing things on the blue tube didnt help me geting any reasonable focus at all.
In the cente itr can be achieved but not out to the left and right edges in the zone-focus page.
Althou i still run on old worn caps in the neckboards, slow delivery of parts to my home it seems.
AND i was a bit lazy and didnt fidle too much with the astig magnets at the back.
AND i have not done zone astig for blue either, cause focus on the other tubes are flawless in the edges.
Gonna do some fidling with it anyways.
Should i expect any better focus when replacing them or should i work my why down to the focus board looking for faulty components ?
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Mon Jan 25, 2010 11:07 pm Post subject: |
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There was another thread here where some one was having issues with focus. it was the astig wave from board on the CLM. Disconnect that board and do the CPC magnets(astig mags) and see if it will focus better that way. get it focused then put the Astig Wave form board back on again see if it changes.
that board is on the CLM.
Athanasios
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wadde
Joined: 19 Jan 2010
Posts: 27
Location: Sweden
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| Posted: Tue Jan 26, 2010 12:34 am Post subject: |
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| Nashou66 wrote: | There was another thread here where some one was having issues with focus. it was the astig wave from board on the CLM. Disconnect that board and do the CPC magnets(astig mags) and see if it will focus better that way. get it focused then put the Astig Wave form board back on again see if it changes. that board is on the CLM.
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I did mechanical astig and cheated the rest of the way with electronical astig (not talented enough and a bit lazy again)
And the side-focus got miles better on blue.
Some really odd setup of this machine earlier.
I found it really hard to get the "brighter spot in the midle" with the magnets.
Gonna try disconecting the electronic astig then...
I suppose there are many threads about this with the astig. So sorry about that chaps.
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