Monitor V-size issue - M Monitor 25" by Electronic System (Hantarex Polo2 clone)

[repetto74]

Hi Guys,

I would like to share with you some issues I have with a new CRT monitor installed in a MameCab machine.
This monitor is a M Monitor 25 inches Dual Autosync 15-25khz. It was manufactured by Electronic Systems in Italy around 2005. This monitor is a clone of the old Hantarex Polo monitor line and was pattented to Electronic System after Hantarex stopped activities. It was still new in box when I got it from an unsold stock.

I investigated and gathered some more information over the net....I am almost 100% sure this monitor has been licensed by Hantarex when they stopped CRT production and has the same chassis and characteristics as the old POLO2 15/25Khz...it's basically the same monitor.

I am using it horizontaly in a mamecab machine with AVGA9250 and Groovymame under XP32. When I fired it up I was glad to see a bright image and very nice colors (there is no video amp connected to the VGA inputs but I assume it's fine as the image is very bright) but started also to notice some hickups...

The most annoying for me is the V-size image which I can't get till the edge of the screen. I have turned the V pot to the far-end position available but there is still almost 10% of the screen still black on top and bottom. Note that I don't have this issue when a vertical game is launched in groovymame and all the available height is used.
I have also noticed some gray shading stripes on the background of the image on the left and right side. It is clearly visible with light colored backgrounds. The pictures I enclosed are self explanatory. The arcade monitor test reveals also some geometry issues which may explain this grey shading.
The image is also not perfectly horizontal but is slightly rotated clockwise. Playing with all the available pots (pincushion, trapezoid, cont, brigh, v-size etc) will not solve any of those issues...
My question is to know what's wrong with the monitor and what action can be taken to fix this??

PS : for a better view of the grey shading do not look at the pictures to close...
PSS : I have enclosed another picture with the mediaplayer background to better show you those grey bands. A big one on the left side over 1/3 of the screen area and a small one on the right side.

Update : I am trying to isolate the problem so I tested with another videocard and same issue on screen. The problem is not coming from the video signal at least.

[repetto74]

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[repetto74]

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[lilshawn]

I'm not a polo expert. I've only worked on one older polo in my life. They were popular in Europe, not so much so in north america.

for your stripedy screen, you may have the brightness/ high voltage turned up too high.

we have been sullied by super bright hi definition plasma and LCD displays. We have forgotten that things aren't supposed to be super bright.

turn it down a bit and see if it evens out.

the vertical size issue is probably just some caps that need replacing. it might be a good idea to get a capkit and replace them. even though it may not have alot of hours on it, the caps will still dry out.

screen rotation is usually a result of the yoke being turned slightly. unless it's obvioulsy really rotated out of alignment, i wouldn't mess with it. You can introduce a whole whack of other issues by messing with it.

[repetto74]

Hi LilShawn

Million thanks for having taken the time to reply 
As you said the screen is slightly rotated you would probably not noticed it if you do not know it is. I do not want to mess with that and maybe get things worse 
I will have a look at the brightness settings and see if I can get clear of the grey bands.

For the V-size issue, as you said a capkit could fix the problem. This monitor was built in 2005 and delivered to me only this year. It has been switched on a couple of time before being delivered to me. I assume that first time power is transmitted to capacitors then they may dry out with time.

I will try to change capacitors involved in the V deflection and see what happens!
Thanks again
 

[grantspain]

right its not your vertical size but horizontal size that is the issue,if you have adjusted the horizontal size to max on the remote board then you need to adjust the horizontal size coil which is located behind the flyback


you have a problem with trapezoid-this adjusted on the remote board-its called keystone(just above the pincushion correction)

[repetto74]

Hi Grantspain,

I may get things confusing when I explain as I am not an expert. So just to be sure this is not confusing :

-My monitor is mounted horizontaly
-The adjustments of the image width is working good. I mean the image from LEFT to RIGHT side of the screen can be adjusted with the H-size pot and I can go off screen as well (is this the Horizontal deflection?)
-The adjustments of the image height is the one giving problems. So the image from TOP to BOTTOM of the screen cannot be adjusted till the edges of the screen (so is this the Vertical deflection?) using the V-size pot
As far as I understood, the width coil adjustment is not the one I need to look at as width is ok. Did I catch this right?

[grantspain]

yeah you are not really explaining things in a way that i understand,too many pictures mate

ok if its vertical size then nothing you can do apart from use graphic card properties

[repetto74]

I am using an arcadeVGA Radeon 9250 with the catalyst drivers for GroovyMame.
Any idea where do I have to set the properties?

 

[grantspain]

no idea i am afraid on anything to do with mame

b+ may be set wrong on chassis and if i am correct those has chassis had some jumpers for matching to various tube types

[repetto74]

Hi,

Yes, correct I have a jumper I can move to select different Horinzontal Yoke deflection inductance depending on the type of tube mounted.

My tube reference is A59P1E50X81 @ 300 μH

I tried already to move this jumper one notch up and one notch down from its original setting but in the first case the image was shrinked horizontaly and for the second the monitor puts itself in a safe mode (no image and intermittent clicks sounds) so I assume I do not have to mess with that and factory settings were correct...

Anyway for the grey shaded area issue I had improved a little bit things by adjusting the contrast and brightness....I have a better result now on screen but those bars are still visible. Is there a proper procedure to follow when adjusting brightness and contrast to have the best possible result?
 

Edit : There is also a jumper to select the vertical yoke resistance (2 positions). Actually it is set to 10 Ohm..I do not think having never changed this one but I will try to move it and hope I will not damage anything.....

[grantspain]

You are a brave man changing the inductance jumpers

if you had an inductance meter and a multimeter you could read your yoke and match it perfectly

the fact you have a 0.300 yoke means that the chassis is similar to polostar rather than polo

[repetto74]

Ok so........

I moved the jumper of the Vertical Resistance to the second available position but this has only a drastic effect on the pincushion and the image is completely squashed from left and righ toward the center of the screen. So original position is the good one I believe.

Concerning the inductance this is were its sound strange.
My monitor is a 300 μH as per what is written on the tube sticker. The jumper for the Horizontal Yoke inductance has those settings
200, 240, 300, 350, 960. Logically it should be set to 300 but it is at 240. As I told if I put it to 200 the horizontal image is shrinked and if set to 300 then the monitor will not turn on (click sounds as the inductance is out of range I believe).
Was it written on the tube sticker is wrong then??
 

EDIT : I may start to think this chassis had a tube replacement with one not 100% compatible. I do not remember but I may have read a post on a tube swap between different Polo chassis where you will loose part of the vertical size by doing that....

[grantspain]

a chassis running 200 mh is more like a wg d9200 or nanao ms2931,its a very high res yoke

[repetto74]

This chassis is close to the old Hantarex Polo2 I think (by the way it is a dual auto frequency 15-25khz) but with this extra feature where you can swap different tube and set the correct inductance with the jumper...

[princess prin prin]

My tube reference is A59P1E50X81 @ 300 μH

The tube is actually a Panasonic A59ECF50X81. A fake label that says "Beta Color" (a fictious company) has been applied over the original label, go figure why maybe some weird legal reason. The tube is also used in some 100Hz Panasonic TVs and the low inductance is regular. All these monitor have this tube afaik. I think you should try with an arcade board.

[repetto74]

Hi princess prin prin

This is exactly what I have! The label "beta color" is there together with an orange sticker stating "PICO color monitors".
I have the original arcade PCB games when I purchased the cabinet but all the jamma wirings have been redone and the Video signal now is directly connected to the videocard. It's gonna be a pain to redo this.
At this point I really think the reason why the V-size is not fitting the enrtire screen is due to some bad caps. This chassis did not operate a lot (it is almost brand new) but has been manufactured in 2004 so almost 10 years ago already

Any chance maybe also to have some links of resellers where I can get another compatible tube?

[lilshawn]

tubes don't go bad...also tubes haven't been manufactured for years. CRT monitors are all but long gone.

there is nothing wrong with the monitor, just needs a little TLC and some tweaks. arcade machines are far from "plug and play". there is some actual work involved in getting things working right.

if there was a giant hole burned through your board and it's been left on 24/7 for the last 9 years and "INSERT COIN" is emblazoned into the phosphors, i'd consider something else to replace it. What you have there is about as close to "cherry" as you are gonna get these days.

[ed12]

u answered your own question

>I am using it horizontaly in a mamecab machine with AVGA9250 and Groovymame under XP32. <

tweak mame

ed

[repetto74]

just needs a little TLC and some tweaks

What do you mean by TLC?? a Capkit?

I was considering a tube replacement because I still have this grey shaded bands issue for which I cannot isolate the reason. I was thinking this is not coming from the chassis but could be a defect of the tube (phosphors or something else). I noticed that those shaded bands will enlarge or shrink when playing with the H-Phase potentiometer. But they give me the idea those are somewhat printed on the screen...

I do agree that the verical size of the picture not reaching the screen edges may be due to one or more bad capacitors. Tweaking Mame will not adjust the vertical size or at least I may need some help from you on how to do this. Except from playing with the V-size pot I do not know what else could be done.

I have posted some close-up pictures to better show you those shaded vertical bands...

[lilshawn]

without actually seeing the monitor, I can't be sure, but i'd wager a guess that there is some ripple getting in the power for your video amp or a cap is going in the chassis that's causing the bars.

your videocard drivers may provide a size adjustment depending on the version you have installed/card capabilities.



if there was an issue with the tube you'd know it. and if the bars move around when you adjust the horizontal/vertical position, it's something in the signal, not the tube.

make sure you have a good ground on the monitor and computer you are using to drive it. also be sure they are using a common outlet, as that can cause noise in the video too.

i'm just throwing a bunch of stuff out there.

[ed12]

mame allows for :off: size
ie horz size=0-x
ie vert size=0-x
u can in the config file set it pre game and or rom u intend on using
it is after all mame...emulator..

ed

[repetto74]

Hi Lilshawn

Thanks again for your suggestions on where to look at.

The video drivers installed are the ATI Catalyst drivers modified to run multiple modelines with an arcade VGA card. Unfortunately the control panel will not give any option to set the H and V size. The tweaking can only be done with pots directly from the monitor chassis.
I have noticed also that some horizontal bars of rumors (noise?) will pop up randomly on the top of the screen. Those waving shaded bars are visible almost with red, white, blue and yellow backgrounds but will be not visible on a background with multiple colors displayed. From what I could read concerning monitors troubleshootings those bars can be caused also by bad capacitors so I am really start to think the issue is coming from there. Those bars would normally disappear after several minutes the monitor is turned on....so could still confirm a cap issue.
I may suspect also hard drives interfering with the monitor but not sure at all. The monitor chassis and the PC motherboard are both grounded.

make sure you have a good ground on the monitor and computer you are using to drive it. also be sure they are using a common outlet[

What do you mean by a common outlet?

Thanks again for your patience 

[lilshawn]

i mean, don't have your monitor plugged into an extenstion cord that plugged in across the shop, and have your computer plugged in on the bench. There is a chance the 2 plugs are on opposite circuits. that can cause noise in audio and video signals that rely on a common ground.

[repetto74]

Hi Lilshawn,

The monitor and the PC are both plugged into an extension outlet which is then plugged to the wallet. This allow to power on both the monitor and the PC at the same time with a single switch.
I will try to plug them separately and see if it make a difference.

I have posted a video which is better than any word for you to have an idea of the problem. The wavy bar is clearly visible on top of the screen over a white background but will not be visible with darker colors (I believe also they will not pop up with certain resolutions)



Thanks

[lilshawn]

both plugged into the same outlet is what you want.

that looks like an interference issue to me. you mentioned a video amp of some kind...what is powering that?

[repetto74]

I am not using any external video amplificator.
The VGA video cable is a normal VGA videoo cable I used to connect the 6 pin video input connector (I am using the one of the old Hantarex 9110 as it is the same) to the monitor chassis video input socket.

If this is an interference, should you see it normally all the time? Those bars are visible under certain color conditions but for most games you won't see them...

[repetto74]

So I made some extra tests and I have figured out something.

First I have redone the ground wirings of the monitor power cord and connected the ground to the monitor chassis as per the manual instructions (I missed this point). This will not resolve this problem and the horizontals bars are still there.

But I have noticed that those bars will pop up after a few minutes only (about 10 minutes) so probably when the chassis circuitry gets hotter. You will not see them the first minutes the monitor is switched on.
Also when I put a game in pause mode the screen will get darker and bars will disappear. They are back once I exit the pause.

I presume one or more electric components are faulty as they get hot (could this be capacitors?)

[repetto74]

Hi,

I have resolved at least the interferences issue!
After a long hardware check of teh cab PC it turned out that one RAM module was originating the interferences. 
I moved it out from the MB socket and now the picture is clean without odds wavings.

Still have to sort out the grey vertical bands problem....