Billabs -- squishing around edges?

[the_77x42]

I have a Billabs BL27CB0P bought almost a year ago for my MAME cab.

Since, I bought it, I noticed that the corners were slightly out of focus (Nokia Test Program showed this), but it wasn't noticeable in game play. My main problem is now the "sqiushing" of the picture along the right edge of the monitor.

It has been around since the beginning, but only really noticeable in certain video modes and games -- especially Paper Boy. It looks like the street is curving in towards you.

I tried adjusting the H-Position and H-Size on the monitor, but that doesn't really help that much unless the screen is very small and way off center. I can make it much worse, however, by making what looks like the picture folding back over itself.

Another example of this shrinking is in Joust or Street Fighter. Any sprites close to the right edge of the monitor will be about half their width as if they were on the left side. The problem occurs mostly for about 30-40 pixels on the right side.

Any suggestions? Are there 'hidden' controls on this monitor, or should I just be calling their tech support? Thanks.

EDIT: I eventually recapped the whole thing and now it works great. Details are here.

[the_77x42]

Here is what the geometry pattern looks like at the Paper Boy resolution (512 x 384):



You can see the egg-shaped circles around the corners.

I've tried more adjustments, but  I cannot get it right. It looks like everything in the center of the screen is fine. So, as the edges approach the center, the geometry corrects. It is interesting that H-Position and H-Size are 'moving' two different things. There is a black area around the monitor that has no light at all behind it. There is another black area inside the picture itself that has light behind it. H-Size adjusts the picture's size across the non-lit black area, whereas H-Position moves the picture within the lit black area. So, if you sized the picture down to 100x100, the H-Position is only going to move whatever is inside that 100x100 box within the bounds of that box. It won't actually move the 100x100 box across to the edges of the screen, for example.

Anyway, that's the extent of my adjustments. There are small speakers above the monitor, but they are in plastic and about a foot away with a 3/4" piece of wood between them and the top of the monitor. I don't think it's the speakers because the bottom of the monitor is affected as well. There are no cords close to the edges of the monitor. The only thing that I can think that would cause this external to the monitor itself is the large steel bracket I have around it, but again, that is bolted to the wood and the only thing touching it is the monitor, no magnets, speakers, etc.

Any help would be appreciated Thanks.

[shorthair]

The focus can be adjusted on the neck board. However, arcade monitors, standard defintion televisions, and large PC monitors (the tubes seem very similar) all have a horizontal gradation of vertical lines. In other words, they're gradually spaced from the center (which is very tight) to the edges (which are noticably loose).

The second issue might be a tube imperfection. I'm wondering why you waited this long to address it.

[the_77x42]

I did adjust the focus at the back, that helped that problem. As for the other, I'll have to call tech support again and see if there are any other controls.

It took me this long to address it because I didn't really start noticing it until I played Paper Boy

[grantspain]

sounds like a capacitor gone faulty in the frame circuit

[ahofle]

I have the same squishing on a brand new Betson monitor (so it's doubtful it's caps).  I haven't found a solution other than to live with it. 
http://forum.arcadecontrols.com/index.php?topic=65920.0

[grantspain]

this could be a manufacture error,you should report this to the supplier unless of course its down to some kind of resolution problem

[the_77x42]

Well, the problem is only noticeable on a couple resolutions... Before I spend an arm and a leg on shipping (I'm in Canada), anyone know how to enter service mode?

[ahofle]

this could be a manufacture error,you should report this to the supplier unless of course its down to some kind of resolution problem

It's worse on certain resolutions and hardly noticeable on others.  The thought of returning this monstrosity to Betson is not appealing.  Does anyone know if they pay for shipping on exchanges/returns?

[grantspain]

if its only happening on certain resolutions from a graphics card the fault cannot be the monitor,for instance if you use a colour bar generator and the picture is fine then the monitor is fine.your next step is to contact the manufacturer and explain what resolutions are causing problems,there maybe a way round this problem or some kind of update required to accept these resolutions whether it be software related or on the chassis itself.
all manufacturers want to improve their product but that can only be done with feed back from the field

[the_77x42]

Well, I did notice that the resolution displayed on the OSD is different from the resolution selected using the ArcadeVGA software. I'm not sure, however, why this would lead to altered geometry on the edges of the monitor.

I'll run some more tests, see what resolutions are acting up, and then contact Billabs. I'll post an update next week.

[grantspain]

if you are running arcade vga cards it may be wise to contact ultimarc to get their take on this situation

[ahofle]

I highly doubt it's the card, because the CGA arcade monitor I used just before plugging in this Betson did not exhibit this problem.  I'm not sure why it would appear worse at certain resolutions, but it definitely does. 
Does anyone know how to run the nokia monitor test on a low resolution without having to switch to it beforehand (switching to super low resolutions screws up all my icons on my windows desktop  ).  It would be nice if the nokia monitor test allowed you to change resolutions.

[grantspain]

i see what you are saying but the cga monitor is expecting a straight cga signal whereas the multisync is expecting anything so perhaps the multisync is getting some kind of conflict problem with the resolution

[Rickn]

Honestly the problem is likely two fold. This is what is called Horizontal Linearity. It can actually be measured as follows:
Measure each square accurately (use the center of each line) record each value. Add all values up and divide by the number of squares.
You now have the average square size.

Now worst case linearity is calculted as follows:

Largest square size subtract average square size now divide this result by the average square size and multiply by 100, the answer is in percent.

Now do a similar calculation on the smallest square size as follows:

Total value of the square sizes divided by number of squares will give you same result as above -> the average square size

Now average square subtract smallest square then divide by average and multiply by 100.

Ok now you have qualified the linearity error.

If it is a single resolution monitor the manufacturer may allow between 12 and 15% error- but please note they will use a proffesional signal generator.

If multi scan it is likely the allowable error maybe on the larger side as the monitor switches various caps in and out.

The next part of the equation is the video card, I have not completed all of my testing on the AVGA, still playing with resolutions etc. so I will not comment in detail, but I will say that it appears to contribute to some of the error.

In a nutshell, it is highly unlikely they would accept the monitor back.

Yeah I know, not the answer you like, but reality.

Good Luck

Rick Nieman
Rick@Niemandisplays.com
www.niemandisplays.com

[Ken Layton]

Does the monitor have a "Horizontal Linearity" (sometimes marked H LIN) control on the chassis? Not every monitor has one of these controls (many do not).

[shorthair]

Neither my Billabs nor it's manual diagram seem to have anything on the chassis that like that. I think it's likely what Rick said. I've notice this, too. It might even be the game drivers for PB (as well as 720 you might notice). Worth investigating and something I noticed before, but since seeing someone else, particularly someone with another brand, experience this, I don't think it's a serious issue.

[ahofle]

The Betson has a horizontal linearity adjustment in the service mode OSD, but all it seemed to do was shift the squishing more from the left to the right.  Since I have pinching on both sides it didn't really help.

I'm still not understanding how this could be the AVGA.  I thought a video card can only send a signal to the monitor and after that it has no control over geometry or sizing anomolies?