Author Topic: Tektronix 222 Display Rotated  (Read 2277 times)

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Offline teconomyTopic starter

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Tektronix 222 Display Rotated
« on: April 18, 2018, 03:09:54 pm »
Hello, I have a Tektronix  222 scope in great condition except the display is rotated.    See attached photos.
I have it pulled apart and have the service manual and have tried all the adjustments that I can find but none will correct the issue.

Any thoughts?
Thank you
« Last Edit: April 18, 2018, 08:36:39 pm by teconomy »
 

Offline Rolo

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Re: Tektronix 222 Display Rotated
« Reply #1 on: April 18, 2018, 04:33:11 pm »
This is a CRT so the coil packet could be out of position. I'm no expert but you can look if it can move and try turning it, beware of VERY HIGH voltage inside.
 

Offline teconomyTopic starter

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Re: Tektronix 222 Display Rotated
« Reply #2 on: April 18, 2018, 04:56:05 pm »
Hi and thank you for your reply,

I tried to gently turn the base  but it  appears that it does not rotate. I am reluctant to apply too much torque in fear of breaking it.

Thanks again!
 

Online ArcticGeek

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Re: Tektronix 222 Display Rotated
« Reply #3 on: April 18, 2018, 06:58:29 pm »
I don't know much if anything about the 222 scope, but I would agree that it sure looks like the deflection yoke is rotated.   There is usually a clamp somewhere on the yoke that needs to be loosed before it can be rotated - did you loosen the clamp?
 
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Online edavid

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Re: Tektronix 222 Display Rotated
« Reply #4 on: April 18, 2018, 07:33:37 pm »
I don't know much if anything about the 222 scope, but I would agree that it sure looks like the deflection yoke is rotated.   There is usually a clamp somewhere on the yoke that needs to be loosed before it can be rotated - did you loosen the clamp?

It's an electrostatic deflection CRT, so there's no yoke.

OP, what happens when you try to adjust HORIZ ALIGN and VERT ALIGN?
 
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Offline james_s

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Re: Tektronix 222 Display Rotated
« Reply #5 on: April 18, 2018, 07:50:37 pm »
Many scopes have a trace rotation coil, if this does then it may have become disconnected or whatever drives it has failed.
 
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Offline teconomyTopic starter

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Re: Tektronix 222 Display Rotated
« Reply #6 on: April 18, 2018, 08:47:47 pm »
I just added an other photo of the interior of the scope.
 

Offline teconomyTopic starter

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Re: Tektronix 222 Display Rotated
« Reply #7 on: April 18, 2018, 09:09:50 pm »
When I adjust the HORIZ ALIGN and VERT ALIGN they appear to operate correctly in that they slide the display on the x an y axis respectively.  They along with all of the other adjustment pots all appear to work fine however none of them address the issue of rotation.

Thx
 

Offline duak

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Re: Tektronix 222 Display Rotated
« Reply #8 on: April 18, 2018, 11:56:38 pm »
I downloaded a copy of the manual from Tek wiki: http://proxy.w140.com/tekwiki/wiki/222

I see on page 3-7 in the last paragraph the 222 uses electronic trace rotation.  I could imagine that too much of the X is being fed into the Y thus causing a major rotation or lozenging.

I don't seem to see any schematics in the above manual so I can't offer any advice other that to check the values of all resistors near the Horizontal and Vertical align trimpots.

Cheers,
 

Offline james_s

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Re: Tektronix 222 Display Rotated
« Reply #9 on: April 18, 2018, 11:59:46 pm »
That sure is a neat little scope, I wish I had one.
 


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