Hantarex MTC900 problems

[Carlito]

I have a Hantarex MTC900 monitor that has been doing some odd things lately.
When I first purchased to monitor it played very well.  This was only about a month ago.

A couple of weeks ago I noticed that the sides of the monitor were not showing movements.  It would kind of flash the pixels on and off of moving characters.  After 10 minutes or so this would go away and the monitor would show fine again.

Then last night I had the monitor on for about 25 minutes and the screen started to show black pixels flashing on the screen in random chunks.  The brightness itself was jumping up and down while this was happening.
Let me know if more info is needed as to what the problem may be.
Unfortunately I lost my digital camera while on vacation a little while back so I can't post pictures at the moment.
If needed, I will borrow a camera and post them.

Thanks

[grantspain]

difficult to say from your description but it sounds more like a game board fault
i think a pic of the problem would help a lot more
a monitor of this age almost certainly would benefit from a new set of electrolitic capacitors
mtc 900 chassis are nearly as old as me 

[Carlito]

If it is a gameboard fault then that doesn't really upset me too much.  I'm planning on converting this to a mame cabinet.
So on that note, I did try hooking the monitor up through a j-pac to my pc and also got some funny results.
After turning the pc on the boot screens showed up as a double screen, which i believe it is supposed to do in this scenario.  The first time the desktop booted up, it stayed visible and centered for about 5 seconds.  Then the V-Hold and H-Hold seemed to just go haywire.
I tried adjusting but the closest I could get was a slow rolling of the screen upwards.  After this, even turning the adjustments the tiniest bit seemed to throw the hold way off.

Any ideas as to how to set this up properly or if there is something obviously wrong with the monitor?

[grantspain]

you will get a double image with vga and it will not lock as the mtc 900 is expecting a 15khz signal,read this following thread
http://forum.arcadecontrols.com/index.php?topic=66402.0
maybe you can use this with your graphics card
your original fault could be a low +5 volts to the game board or a bad eprom seating

[Carlito]

The double image was expected, i meant that this is what I thought should be happening.
I am using Soft-15KHz with my graphics card.
The problem was that the first time the desktop loaded (using Soft-15KHz) it looked fine for about 5 seconds..
Then the V-Hold/H-Hold problem came up.  No matter how much I adjusted those i could not get the picture to hold.
The adjustments seemed to be way too finicky.  I would barely turn the v-hold or h-hold adjuster and it would be like I cranked them one way or the other.

[Carlito]

BTW, thanks for helping me with this.
I know my knowledge is very limited and I appreciate the patience.

[grantspain]

this is a setup/signal problem,i can't help you with mame stuff as i am not familiar with it but i do know you get very sensitive adjustments with the wrong signal/seup
if your original game board locks then the monitor is o.k
maybe its best to ask other people their setups using a standard cga monitor

[Grauwulf]

If you are not able to lock in your H/V hold you probably have a low-signal problem. The monitor is expecting a 5v signal from a game board, where a computer video cards typically sends out a 1v signal. You will need a video amp of some kind. If you're using a J-pac for your interface, it will do that for you as well as split the signal when it is out of range.

[Carlito]

I am using a J-Pac...so now I'm confused.
The J-Pac has an onboard video amp.  Is there any other reason for this?

Edit:  Also, on the Ultimarc site it states that Hantarex monitors do not need the 5V..

[Grauwulf]

How do you have your sync hooked up? Hantarex monitors are notorious for being finiky on how the sync is hooked up.

[Carlito]

  how do i check that?  Sorry, i'm not sure how...

Do you mean how am I sending it 15khz?  I'm using Soft-15k

[grantspain]

you have 2 sinc connections on the mtc 900,horizontal  and vertical-you need to play with these

[Carlito]

ok, i really am a noob..and I have tried looking up the definitions of this stuff, but how would I go about 'playing' with these connections?

[grantspain]

you should have 2 sinc wires(usually yellow and white)that connect to the signal input plug of the monitor chassis,when i say play with these i mean try different combinations of these wires connected to the jpac e.g both connected/yellow only connected/white only connected

[Carlito]

Well, still no luck with the monitor.
Originally in the cabinet it had both H and V Sync connected together which seemed to work fine with the Jamma board.
I've tried connecting just H, and just V but the problem is still there (very very sensitive H and V sync).

I've emailed Andy at Ultimarc who seems to be as confused as I am about this weird sync problem. 
After troubleshooting some stuff with him, he has suggested returning the J-Pac so he can test it.

I'm just wondering if anyone else has any other suggestions to try before sending my J-Pac back.

Thanks In Advance,
Carlito