Amplifone - diagonal collapse?

kiphartzell

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What would cause a single diagonal line across the monitor? Background: I just received a replacement 25" Amplifone tube for my SW CP including a new purity mechanism. I swapped my yoke onto the new tube and installed the purity rings but have been unable to make any purity or convergence adjustments because I can't get the test screens to display on the monitor beyond a collapsed diagonal line. The deflection and HV cards have been rebuilt following Michael's FAQ including the recommended enhancements, but these cards are untested too because of the previous bad tube I had. I verified that the game board is generating the test screen using an X-Y O-scope (also, deflection led is out and I hear the normal deflection chatter). The X-size and Y-size pots will cause the diagonal line to grow in length, but doesn't change the collapse in either (both) directions. Also, the HV card has a Penntron HVT and is generating 19+KV. Anyone know what to look at next? Can a yoke or purity mechanism be that far off that it can cause this type of problem. Any reason to believe the tube may have an internal issue with the guns? I did test the tube before powering it on with my B&K 490 and everything checked out.
 

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could that really be vertical collapse and the yoke just needs to be turned ?
Edit: Just realized you said spot killer is off and you have deflection chatter.
 
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I think it could be vertical or horizontal collapse with a yoke that needs adjustment. If your input signal is good, your spot killer should be off, and you do have some deflection, so there'd be some deflection chatter. How about scoping the yoke pins? If it's collapse, you should see change only in one axis. If that's truly slewing corner to corner, you should see nearly equal voltages on both axes.

And you don't have something like both X and Y inputs connected shorted to the same game output (X or Y), right? Driving X and Y with the same input would create a diagonal line.

DogP
 
Some good responses. Thanks. When I get home today, I'll try rotating the yoke to see if I can get the line to rotate with it. I will also look for any shorts between the X & Y.

A couple of observations;

Again, I know the X & Y inputs to the deflection card are fine because I have them up on my O-scope (at the game card). But I'll move my probes to the deflection card to double check the harness, etc.

Second, the size pots cause the line to grow/shrink in length. What I recall, the x-size pot seem to grow/shrink the line in the upper right corner the most and with the Y-size pot, the line mostly changed (grew/shrunk) in the lower left corner. This would seem to indicate that I am getting both X & Y out to the monitor since I see variation when adjusting both pots.
 
I just received a replacement 25" Amplifone tube

My question is where did you get a replacement tube? Seeing a 25" tube with no phosphor burn alone is odd. Where I'm going with this is I'd verify that first of all that is the correct tube.
On the back of the TUBE you'll see a sticker with the tube model number. Post that here.
 
It is a A63AAX00X picture tube which matches what the original was. I even double checked the glass embossing on the tube and it is clearly a 25V100 tube just in case the sticker was incorrect/inappropriately applied.
 
Yes, $175 would be a good deal for the tube though I would be leary with what you would really get based on the description.

Part Number:
A63AAX00X
Company:
EMPIRE VIDEO Description
PICTURE TUBE USE A63ABZ26/40X Price
$175.00
I got my "new" replacement tube from Scotty @ Hawkeye for a few bucks more then this, but am very happy with the overall condition and how clean the screen is - absolutely no burn-in or phosphor burn - very sweet - Like brand new! The guns are new and I am also using a new purity assembly.

Since I had a complete SW CP, buying a replacing tube seemed to be the best solution when I discovered my original tube was busted (Would not generated HV when attached to anode).
 
Deadly - you mean J103 connector for HV connector. And IIRC? NOt sure what you mean, then you want voltage measurements for -,+,B+ going to HV card or am I misunderstanding??

As for yoke orientation, I rotated the yoke 45 degrees and the line is now vertical (the other direction by 45 degrees made it a horizontal line), but base on the text updating on the screen, it looks to be a full horizontal collapse. I had the yoke on the replacement tube based on the original tubes yoke orientation. Any ideas why it would be 45 degrees out of syn between the two tubes? See pics...
 

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its probably one or two of the bottle cap transistors on the heatsink. Verify they are not dead/shorting out, and you have the correct ones in the right place..
Does your deflection board have the pots? if so do they have any effect?
 
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The latest - all the problems were related to the deflection card which caused the diagonal collapse. I still need to debug the problem, but I finished rebuilding a second deflection card and this card worked much better!! I even was able to put the yoke back to what I thought should be the correct orientation. Picture is reasonable now, but the fun begins with setting purity & convergence!!!

As for the first deflection card (it is green), I am still open to suggestions with what to look for. All T-03s, MPS-U07 & MPS-U57 are new and in the correct spots with no shorts to the heat sink. This card also has the diode modes, Wx's were replaced with wire, new caps, and new pots for X&Y sizing, etc.
 

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