Neotec NT-27E semi-functional pincushion...

stouchton

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Hi,

Looking for some pointers on the above mentioned monitor with a permanent barrel distortion.

System has been re-capped, new flyback and new HOT. All works well except for the permanent barrel distortion. Pin cushion control will not pinch the center, only aggravates barrel distortion. Phase control does not shift position as manual suggests, only gives slight illusion of "tilting" top of screen.

Vertical and horizontal position and size adjust correctly, so I believe all is well in deflection land.

Since the vertical deflection is OK I assume the input to the pin cushion board should be fine. So I am pondering the NPN and resistor on the output that modulate the horizontal signal.

Appreciate any clues and pointers - figured someone might have bumped into this one before.

Thanks - been a long time reader of the forum and have appreciated the help you have supplied.
 
heres a manual in case you dont have one...

http://www.vidiot.ca/manuals/Neotec_NT-2X.pdf

Let me do some digging...

Supposedly there is a bipolar cap on the right side of the chassis.. approx 200volt unsure of uf.. according to one webside, others say itsa a 50v bipolar on the pincushion board itself... that when it goes bad you have almost no width adjustment and pincushion adjustment.



I think bob roberts offers a pinchshion board capkit for like $5 or something, might want to give that a shot.
 
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Thanks Cadillac....

Been recapped, and bi-polar replaced with appropriate part (Nichicon UHA1H5R6KHD).

Just seems the pin cushion effect on the horizontal sweep is limited - only has a slight effect.

ALSO - the barrel distortion is minor, most folks don't notice. I have the game (Cruis'n World) tucked away in my engineering lab at work to refurb for a xmas gift. Co-workers been putting runtime on it for me and no one noticed.

I just get anal about things being perfect, and know the pin cushion is not adjusting properly.

Was hoping someone could shortcut hunting down the culprit for me.

Take care,

Scott
 
a clue....

This is getting interesting...

I rebuilt most of the pin cushion board (only did electrolytics before), with no change in image.

I then disconnected the pin cushion adjustment pot - so now there is no signal presented by V+ from vertical deflection and low and behold I have a nice square image.

My maximum horizontal deflection is a squeak small, but only a squeak.
 
interesting... well, you know where to dig.

Id also make sure the pot for the pincushion is the correct one. and verify with a meter that its ok and not worn out/cracked.
 
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