Problem with new 25" Polostar

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Andypc
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Problem with new 25" Polostar

Post by Andypc » March 5th, 2009, 11:50 pm

I recently managed to get probably the last, new 25" Hantarex Polostar tubes from direct from Hantarex and managed to get a new Polostar chassis from Electrocoin. The chassis is definitely the correct one for the tube. A K Amusement in Stoke Newington put it all together for me in my old Polo Monitor Frame. The first problem was that it wasn’t automatically switching voltage when tested on different frequencies. The monitor engineer at AK was extremely helpful and was able to fix that problem.

The current problem is that if I turn the Contrast/ Brightness up especially on a white background the following happens.
Monitor 411b.jpg
I have to set the Contrast/Brightness very low to prevent this from happening, but it looks way to dark and I am also having problems with expanding the screen horizontally. When I get close to the edge it will stop expanding in the middle and distort. Also when I set a white background to almost fill the screen, if I switch to a red green or blue background it’s noticeably smaller.

Is there a problem with the Scan Coil / Tube /Chassis. I hope it’s not the tube, as I doubt I will be able to get another.

Any Ides's?
“You can have it any colour you want, so long as it’s black.” Henry Ford
Wanted:- Tehkan World Cup cab

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grantspain
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Re: Problem with new 25" Polostar

Post by grantspain » March 5th, 2009, 11:55 pm

what is the tube make,the polostar chassis were made for many different tubes and have a vast amount of different components depending on which tube it is installed in
and are you sure you don't have a 33" polostar chassis

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Andypc
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Re: Problem with new 25" Polostar

Post by Andypc » March 6th, 2009, 9:12 am

The Tube is an LG Phillips A59EAK552X44. The Chassis is definately a Polostar 25/28 and actually shows the tube right number on the back. The only thing i'm not sure about is if Hantarex put the right scan coil on the tube? I have no idea how I can tell or if that is the problem :?
Monitor 413.jpg
Monitor 414.jpg
Monitor 415.jpg
“You can have it any colour you want, so long as it’s black.” Henry Ford
Wanted:- Tehkan World Cup cab

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grantspain
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Re: Problem with new 25" Polostar

Post by grantspain » March 6th, 2009, 10:19 am

LG Phillips A59EAK552X44
you will need to check the following component values are correct
C4 820nf - frequency switching board
R35 680k ohm- east/west correction board

Neck board
R35 - 4R7
R22,R25,R28 -6K8
R24,R27,R31 -22R
C15,C16,C17-300pf
R23,R26,R30-470R

try looking at those are all the correct values first,I have once seen this problem when a tech put a polo2 28" vga chassis on a polo 2 dual 33" crt

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