Betson 44-4070-RT - Picture is squeezed on right side

[DeLuSioNal29]

Hi all,

Ever since I installed my Arcade VGA card a few months back, I've noticed that the right side of my monitor seems "squeezed".  I haven't had time to mess around with it, but it's really bugging me now.  I've tried using the "secret" menu that has additional options on it, but nothing seems to work.  So, I go to the experts for some advice.   

I've taken several pictures with the monitor test by Nokia running so that you can see the detail of what is happening better.  I've also included a couple of pictures of Gauntlet (look at the keys in the picture and how they distort at the right) and Mortal Kombat 3 (notice now the names of the characters are squeezed on the right side... also notice how subzero looks smaller on the right side).

Any insight on how to fix it would be great.

Here are some pics:

[DeLuSioNal29]

Here are the in game pictures with the problems mentioned above:

Notice on the closeup of Gauntlet, the score that is in RED... the zero's look very different.  The one on the left is perfect.  The one on the right is skinnier.

And again, in MK3, the word Scorpion is squeezed on the right.

[ahofle]

It seems to be a common problem with Betsons these days and the reason I don't recommend them.  Mine does the same thing.  It's a shame because everything else about the monitor is perfect to me.  There is nothing that can be done to fix the problem unfortunately (at least nothing that I've heard around here).  Search the monitor forum and you'll find a bunch of other people with this problem. 

Just out of curiosity, did you get yours back when they were on sale ($369) like I did?

[DeLuSioNal29]

Yep, on sale.  And I picked it up myself to save on $120 shipping.   

[ahofle]

Could you add your vote to the poll I just put up?  I'm starting to have a sneaking suspicion that the bad batch of monitors were mostly the ones they put on sale. 

[MonMotha]

Mine is an old one, and while it doesn't do this as badly, it does exhibit it to some effect.  Are these the 2914DF (completely flat) or just the 2914F (moslty flat) variety?  The DFs may do it a little worse as perfectly flat CRTs tend to have poorer geometry.

This can be reduced a bit at the slight expense of perfectly straight edges (just overscan the picture ever so slightly to make it appear straight again).  Skew the picture with trapezoid so that the top is skewed to the left.  Then correct it back out using parallelogram, pincushion, pinbalance, and top/bottom corner (in that order).

[ahofle]

I don't suppose you could post a little more detailed guide to doing the corrections?  I have tried many different things and had no luck at all.

[Ummon]

I wouldn't call that squished. I'd call it stretched. Like around a curved surface, inward (away from the viewer). I've found this can happen depending on how the monitor interprets (or misinterprets?) the signal being sent, and sometimes little tweaks in the modeline can help or rectify it. (Advancemame, yes, the chosen one. May it rise again.)

[qrz]

just curious, would there happen to be a horizontal linearity control anywhere ? ( pot/coil/menu setting )


qrz

[MonMotha]

just curious, would there happen to be a horizontal linearity control anywhere ? ( pot/coil/menu setting )

qrz

There is one in the service menu.  However, the squish is only on the VERY far right side of the screen.  Only affects about the last two columns of the grid pattern on a neo-geo test screen (if you want a reference).  The Horiz linearity control affects the linearity of the whole screen pretty well equally across the entire screen.  Further, even adjusting the controll all the way to the appropriate extreme doesn't fix this, and it can make the rest of the screen appear squishy in the other direction, too.

As for the adjustment I performed, I did it a long time ago when I spent several hours (!!) messing with my monitor.  What I said before is about all I remember.  Basically, it involves intentionally making something bad then correcting it back out using other options to reduce the linearity issue at the expense of perfect edge geometry.  What I did didn't fix it completely, but it made it a bit better.  Mine wasn't all that bad to begin with, though.  This is a much older monitor than many people on here seem to have (I actually bought it used almost 3 years ago).

Another thing to watch out for that can make things like this worse is abuse of the corner controls.  The top/bottom corner controls are a last minute tweak.  You should get everything else as close as you possibly can before adjusting them.  If you overuse the corner controls, it will squish other parts of the screen.

[qrz]

tnx for the comment, MonMotha

hmmmm, it now sounds like a minor engineering change may be in order . 

happen to have a  link for the schematic ?

qrz

[DeLuSioNal29]

just curious, would there happen to be a horizontal linearity control anywhere ? ( pot/coil/menu setting )

Yes, it does have it, but in the advanced menu (Hold the UP key while powering up the monitor).  But adjusting it does not help.

~ D

[MonMotha]

tnx for the comment, MonMotha

hmmmm, it now sounds like a minor engineering change may be in order . 

happen to have a  link for the schematic ?

qrz

http://www.retroblast.com/files/KT-XX14X-SM.pdf

Let me know if you happen to come up with any ideas.  Mine isn't too bad, and this isn't too noticable anyway on most of the games I play, but this seems to be REALLY bad for some people.

[qrz]

tnx for the print . would be easier if had the model to play with   
c'est la vie !

just for kicks , MonMotha, lets raise the value of c701 to 2.2uF or 4.7uF @50v and see what/if it changes.

pse advvise results..... tnx

qrz

[MonMotha]

tnx for the print . would be easier if had the model to play with   
c'est la vie !

just for kicks , MonMotha, lets raise the value of c701 to 2.2uF or 4.7uF @50v and see what/if it changes.

pse advvise results..... tnx

Well, you're welcome to come tinker with mine some time

I don't have good stock on components like this (I mostly do digital), so I'll have to acquire those before I can try it out.  May be several weeks (and/or months).

[qrz]

just watch for junk tv's/electronics on trash day .  can get plenty of "test" parts - CHEAP   

qrz

[qrz]

based upon this thread : http://forum.arcadecontrols.com/index.php?topic=84372.0;viewResults

there may be need for a yoke modification, or perhaps just in the 15khz yoke timing circuitry .

i wonder if Rickn would happen to have any "dirt" on this  ?

qrz

[Rickn]

Yes, this is a horizontal linearity problem and thr fix will br thr value of one of the horizontal hi voltage caps. I do not have a schematic and have not seen the Kortek in question, but these caps are usually close to the flyback and HOT' Thet are polyrpopelen usualy 1.5 kv rated.

In the case of multi sync monitorsm various values are switched in and out of circuit depending on the resolution. The trick will be determining which ones are in the circuit in standard res. one will determine primarily the width, the second is the "S" capacitor and it effects the width but also shapes the sawtooth waveform that causes the horizontal sweep,

This is not an excercise for someone who does not know what they are doing and for sure you better have spare parts.

Good luck
Rick

[MonMotha]

The schematic (URL posted above) details the S-correction fairly well.  There are 3 S-correction signals output from one of the ICs.  These do in fact switch various members in and out in the horizontal output section.  A table is provided as to what the S-correction outputs are (i.e. which ones are one and off) at various resolutions.

[qrz]

tnx Rickn .

the consensus seems to be that the problem is most prevelent on the 15khz setting .
all 3 caps are then active .
 however,  changing capacitance here will only affect the width , rather than address
the shape of the correction waveform. ( yes , the hv will vary slightly due to duty cycle on the HOT )

the H lin input ( q701,2) and ic701 will be areas of interest ...... now to get a sample to play with .......

qrz

[lettuce]

Have the same damn problem with my Pentranic Quad-Sync 29" Monitor, annoying isnt it!?.

The display is perfect in 25 and 31khz mode, its only in the 15khz mode i have this squished effect on the far right of the screen, sods law that the majority of mame games run in 15khz mode!!!!!  There is an option in the advanced menu that you can alter the HF but it only adjusts the left side of the screen not the right    . I think its just one of those things we'll have to live with!?.

 I am only running mame on my cab via a PC, and dont have jamma at all in the cab, it would be intresting to test the monitor on a proper setup with connecting the monitor to a game pcb board to see if my, pc/gfx card/VGA connections were somehow interfering with the signal my monitor was getting and was causing the problem, but seeings as i dont have jamma this is unlikely to happen.

I did resort to running all my games in double resoultion, with the help of soft15khz program, and setting prescale of mame to '2' instead of the default '1' and enabling the scanline effect, so all your games run in 31khz mode, info here....

http://jvspac.kirurg.org/?page=mame

the only side effect to this was becuase of the scanline effect being applied to the screen, it caused the display not to be as vivid and vibrant as it usually is  .

This is the excel spread sheet i used to get my double screen resolutions to use with soft15khz if your interested in trying this method....

http://jvspac.kirurg.org/files/31k-modecalculator%20v1-0.xls

[Ummon]

Lettuce, if your monitor is capable of 120hz refresh, you don't need to do all that stuff in mame.

[lettuce]

It is capable of doing it, but the spec sheet say its only does up to 90hz. I did ask harry at pentranic if it was safe to use it this way, he said it will work but your just asking for the monitor to fail, as its not designed to be used at that refresh rate. So i stopped using it with 120hz refresh rates, as i didnt want it to shorten the life of the monitor, plus the fact that pentranics have stopped production of these ctr monitors i dont want to risk it really

[Ummon]

Mmmm, yeah, there are a couple games, mainly the later Do's, that I set for 120hz. Perhaps due to a limitation of my card, Advancemame won't run a clock lower than 5, so I run those at 120. It otherwise runs it at 60hz progressive, and I've messed around with the effects, but it's the difference in brightness that I have a hard time accepting.

[DeLuSioNal29]

Thanks for all the info guys.  I've recently looked into contacting Betson about the problem (monitor is less than a year old).  I don't really want to mess around with anything on the monitor itself.  I'd rather have qualified people do that.  As for the workarounds, again, I'd rather not.  The monitor is supposed to work a certain way so why should I settle for a workaround?  I'll let you know what happens once I contact them.

~ D

[DeLuSioNal29]

Good news.  My unit is still under warranty.   

Better news:  I don't have to ship the whole unit out to them.  I can just send them the PCB board and it will be fixed in 1 week's time.   

I'll post the results once I have everything up and running again.

~ DeLuSioNaL

[Ummon]

Hopefully it's just the chassis.

[DeLuSioNal29]

Update:  I just got off the phone with the technician at Betson and he said it sounds like it's the chassis and not the tube itself.  It has been officially RMA'd.  So I'll have to discharge the monitor and remove the chassis to send it to them.

I'll let you know how it works out.

~ DeLuSioNaL

[ahofle]

Hmm I thought you had already determined that a couple posts above?
I'm watching this with interest!

[DeLuSioNal29]

Hmm I thought you had already determined that a couple posts above?
I'm watching this with interest!

Yes, I had, but I confirmed it by speaking with an actual technician this time.  I just sent it out today.

If I had to guess, he's probably going to recap it.

Either way, I hope the problem gets fixed.

By the way, where did you set up the poll?

~ D

[ahofle]

http://forum.arcadecontrols.com/index.php?topic=84372.0

[DeLuSioNal29]

Update:  They received the monitor yesterday (11/18).  Let's see how long it takes them to fix it.   

[DeLuSioNal29]

Another Update:

Bad news actually.  They received it and the tech tested it out.  He said that nothing was wrong with the chassis and that I'd have to send them the rest of the monitor so that he can check it out and manually adjust it if necessary.  (I'll have to drive it out to them in NJ).
 

I was kind of hoping that they found something wrong with it, but nothing. 

However, I'm thinking that I may just bring the whole arcade out there to show them exactly what is happening, and then I can remove the control panel and computer once I'm done with the "demo" and leave the rest.  (It's a huge pain to remove the monitor, since I removed the brackets from it.  It's easier to just bring the whole arcade.  But I'll have to mull this one over a bit.

Sigh.

~ DeLuSioNaL

[grantspain]

the reason they find no problem is because this geometry issue only exists on 15khz and it will differ using different game boards

[DeLuSioNal29]

the reason they find no problem is because this geometry issue only exists on 15khz and it will differ using different game boards

Not necessarily.  The problem I am having happens in all modes, as shown above in the Nokia screen test shots (native windows program, not MAME).

~ DeLuSioNaL

[grantspain]

the reason they find no problem is because this geometry issue only exists on 15khz and it will differ using different game boards

Not necessarily.  The problem I am having happens in all modes, as shown above in the Nokia screen test shots (native windows program, not MAME).

~ DeLuSioNaL

going via an arcade vga card?

[DeLuSioNal29]

going via an arcade vga card?

That's correct.  The betson Multisync monitor is capable of displaying up to 800 x 600 @ 60Hz.  I have windows running at the highest resolution possible @ 60Hz.  It does not matter what Hz I run at, the problem still persists.

[grantspain]

what we found on kc forum is if you ran these tri syncs with a dedicated 24khz or 31khz signal there were no issues,when a 15khz signal was used this is when the problem began
for example i ran tests on tri sync chassis on different donor tubes
using a sega naomi game at 31khz output gave an almost perfect picture,then running the same game using the 15khz interlaced option of the mobo gave side compression and pretty severe
hooking up to sega med res game like sega rally gave a great picture
then  i hooked up to a few 15khz games and varying amounts of side compression

what i am trying to say is your avga card only puts out a 15khz signal --i may be wrong though as i don't own one
i wonder if you would get the same compression with a standard vga card at 640x480
ignore me if i am talking rubbish

[MonMotha]

what we found on kc forum is if you ran these tri syncs with a dedicated 24khz or 31khz signal there were no issues,when a 15khz signal was used this is when the problem began
for example i ran tests on tri sync chassis on different donor tubes
using a sega naomi game at 31khz output gave an almost perfect picture,then running the same game using the 15khz interlaced option of the mobo gave side compression and pretty severe
hooking up to sega med res game like sega rally gave a great picture
then  i hooked up to a few 15khz games and varying amounts of side compression

what i am trying to say is your avga card only puts out a 15khz signal --i may be wrong though as i don't own one
i wonder if you would get the same compression with a standard vga card at 640x480
ignore me if i am talking rubbish

I have noticed this on mine, though my linearity is nowhere near as bad as some have described.  SVGA, VGA, and EGA timings are all fine.  Things look extremely good.  I hesitate to call it perfect, but it's an amazing monitor.  At CGA timings (15kHz), there is a small amount of compression at the right.  I was able to adjust much of it out using the H Lin control in service mode combined with pin, pinbal, trap, paralelo, and corner controls (though it took a lot of time).

The newer KT-2914DF (which has the perfectly flat tube) does seem to do it just a little even at VGA (seen in a PIU neo-SX cabinet), but I haven't tried to adjust it out at all.

Rick Nieman has suggested it is a design flaw with their s-correction.  I don't think anybody has investigated further.

[Ummon]

Way back Rick also mentioned how unstable these can be due to the wide range of scan rates they try to do. My Billabs will bounce back and forth at 15khz when I call and exit the OSD. In some games, even though they don't change res between different screens, there's a similar effect that occurs.