8liners chassis problem

[Cisek]

Hi
I've got problem with centering the image on my Hantarex Polo tube with 8liners chassis, h-size position potentiometer "jumps over" the center position, making the image go far too right, or far too left. I made a video that shows the problem -

I would be very grateful for any help.

[grantspain]

bet it don't have a problem with a jamma board connected,reckon its something to do with you pc side

[Cisek]

No it don't work with jamma either.
The problem is the postion of the image - I can't center it, it's too much to left side, or too much to right side of the screen. The edges are cut for few inches, looks like don't display the whole image, even if I narrow the horizontal width. When turning the h-pos pot it is "jumping over" the center. I noticed also that the image is shaking a little bit, it looks like some kind of noise, however when I turn the image maximum to the right or left, the shaking noise disappears.
I am using new 8liners chassis on Hantarex Polo tube. Looking forward to your advices.
Narrowed screen -

[grantspain]

you get the same problem with a jamma 15khz board connected?
what was the original chassis and what is the replacement model numbers?
what are the yoke reading?

[Cisek]

The original chassis was geniuine Hantarex Polo chassis. I bought an MK2 cab with all original, non-replaced components. Thge replacement chassis is 8liners chassis for 25" monitors. I can't read the yoke, as I don't habe multimeter.

[grantspain]

o.k should be good,you may have a faulty chassis-have you contacted 8liners yet

[Cisek]

I am waiting for their reply.
I noticed also the image isn't displaying the whole resolution - the right and left
sides of the screen are cut of for a few centimeters. It is visible in the
second video i made (look at the timer on the right bottom corner, and on the
windows logo on the left bottom corner to see it).
I was given an advice to adjust he horizontal width coil on the
chassis itself, however I can't find it on 8liners chassis (on original hantarex chassis I know where it is) and I don't know if this will help.
I also found info that on the chassis there is 3 position jumper for small/medium/large horizontal width (first post) - http://forums.webmagic.com/ubbthreads/showflat.php?Cat=2&Number=317415&an=0&page=0
I can't localize this jumper however.

[grantspain]

if i had a good photo of the chassis i could probably id the jumper(if its there)

[Cisek]

Ok i found one jumper, but it is just for switching between H+V and V.C.
I still can't localize the coil, I found the pot that is there where should be coil, but it adjusts the V-size, not the H-size (I marked that pot with yellow circle) - http://img98.imageshack.us/my.php?image=dsc03590qp0.jpg

Also noticed there is some yellow paste around one capacitor and dunno whether it is OK, or    this cap already got dried out - http://img233.imageshack.us/my.php?image=dsc03592lw3.jpg

The chassis is Jen Shinn, model 329.

[grantspain]

i do not see any width jumpers on the pics you have supplied
the stuff around the cap is glue-wonder where the other cap is though(maybe a u.s modification)
i can't get on the jen shinn site to check the specs
this could be a faulty chassis-how long have you had it?

[Cisek]

This is the third day. I bought new one from genao.com
All other things are great - contrast, brightness and that stuff, only h-position is bad. Maybe it's tube fault? I remember that on old chassis I had similiar issue, but with v-size (The picture was too much stretched vertically and I couldn.t shrunk it)

[grantspain]

i have done a lot of chassis swaps and the likes,important that the yoke matches the chassis
i believe your yoke is o.k as you would have more geometry problems and this is not a tube fault
the problem is the picture is way oversize on the horizontal so you can't lock the hold or centralize the pic
now the only things to cause this would be the horizontal width adjustment not working,fault on the width circuit or b+ too high
i know these chassis work on polo as i helped someone else the other day with this setup
you have adjusted the horizontal size yes?

[Cisek]

Horizontal size pot is working, however the picture can't be centered the problem seems to be the h-postion potentiometer. I set B+ lower, but it didn't help. All other things are good. Geometry is excellent.

[grantspain]

tried the horizontal hold yet and what sync connection are you using?

[Cisek]

I am using composite sync I don't know what is horizontal hold.

[grantspain]

maybe called horizontal  frequency pot on the control board(normally)

[Cisek]

Tried all the pots on control board, no one helps.

[grantspain]

how narrow does the picture adjust?

[Cisek]

It can be narrowed really much, that there are huge black boarders on the left and right side. However when it's narrowed the left or right edge of the screen is a little cut of (the cut side depends on how I will adjust the picture by the h-pos pot - it can be too much to left, or too much to right). It just dont display horizontally the whole resolution, even when narrowed.

[grantspain]

got to be a faulty chassis,get it swapped

[castlesteve]

Ive had quite a few of these things.  For the most part they work ok.. but are very tempramental with some tubes and yokes.  Even to the point where it wont even warm up the tube some days but will on another identical tube and yoke.

So, if you have the ability, try another tube/yoke before you return.... else I think you will end up in the same situation.  8liners guys will not really work with you on diagnosing the problem nor will you EVER get a schematic.

is what it is.

[Cisek]

I managed to fix the problem. Instead of moving image to the right I decided to manually change the soft15khz resolutions that I am using (which however originally worked good on my previous chassis). As you know, or maybe not this is a program that can create custom resolutions. So for example I can have all the arcadevga resolutions with good old Radeon 9550. I contacted the creator of this program and he told me how to change resolutions to move it a little to right. It was a little bit difficult, however now all resolutions are centered and they are not cut of by sides.
Thanks a lot for your help.

[grantspain]

thats why i asked about if you had a jamma board to test it with,90% of these type of faults on all the arcade forums are caused by graphic card setup
glad you got it sorted

[Ken Layton]

All these monitor replacement boards were designed to be used with a real arcade board video signal. Never intended to be used with other sources.

[Cisek]

There is still one, minor problem - when I stand close before the screen, the image seems to "shake" a little bit.

[grantspain]

There is still one, minor problem - when I stand close before the screen, the image seems to "shake" a little bit.

probably still something to do with the graphic card setup

[Cisek]

I am using connections from this picture -

I noticed also I have linearity issue. The space beetween the bottom lines of the image is tighter than on the top. The more to the top of the image, the bigger are spaces beetween lines. It's very noticable when playing vertical shmups.
I think there is the pot on the chassis that regulate the linearity, can you tell me where it is?

[grantspain]

look carefully for a v.lin pot-if i had a schem i could tell you

[Cisek]

I've found this pot and adjusted it. I just can't believe that the 15 year old tube, which for it most time was used for 6-7 hours daily, may produce such a vivid and colorful display. The image is still a little "shaky" hiwever it is only slightly visible, when looking very, very close to the screen.
Thanks a lot for your help.
Time to play some mame!

[grantspain]

happy days