Need help: distorted picture on MVS / Supernova setup

[neojedi]

A short history... the problem is that my 6-slot runs fine for awhile on the Mass supergun, but the picture gradually degrades until it is completely distorted. I had originally assumed that this was due to my homemade jamma adapter, and was planning to build a new one. Fortunately the problem does not happen at all using my 1-slot on the exact same setup.

But just a short while ago a fellow MVS owner posted this on SRK:
"I just received my 1 slot MVS today and unfortunately have a problem . I picked up both Garou and SS2 but after just a few moments of play time the picture quality starts distorting (gradually getting worse) untill it becomes totally unviewable . Is this a problem with the MVS itself or my set-up ?
Both carts do the same thing and I tested my SuperNova against a CAPCOM CPS2 and the CPS2 worked fine ???"
---

So if the same problem can occur on a 1-slot, I'm beginning to think that maybe something other than the adapter was responsible. After all, aren't all 1-slots pure jamma? Please provide any information you know about this problem, thanks!

[ October 01, 2001: Message edited by: neojedi ]

 

[Arakon]

it could be that the power supply is too weak, or it might be heat related. try pointing a fan on it.

 

[doughboy]

If it's fine when you turn it on then starts getting worse then it could be a dodgy joint on the mvs.

Since it's cold when you turn it on the joint would heat up after time causing the connection to detiorate.

BTW, no mvs is pure jamma. The 1-slots are nearest though due to only needing 2 extra wires, 2 d buttons.

 

[neojedi]

Thanks for the suggestions, but any ideas on how to troubleshoot? A bad connection sounds difficult to find. As for power supply and heat, my understanding the best solutions for those are both electronic (heat sink / fan on board for the 2nd problem). But my 1-slot runs fine, so the bad connection is more likely. I was wondering mainly how to go about fixing this or getting it fixed. Specific problem determination is still the hard part (ie exactly which connection / part is bad).

Edit: also, on the jamma remark... from the point of view of a Supernova owner the 1-slot might as well be jamma because the setup reads the kick buttons through the 56-pin connector without any extra work. By not jamma I'm really referring to the multislot boards where the sound and other connections are on different pins and they mess up if you don't build an adapter.

[ October 02, 2001: Message edited by: neojedi ]

 

[doughboy]

I would give the board to a local electrician. It sounds like it's a weak joint on the board and nothing else.

Good luck....

 

[Shin Guile X]

I am no expert by any means but I have heard that the six slot requires more juice than the other MVS boards. I also have a Super Nova and have had no problem with it using my 2 slot.

 

[mainman]

There is a resistance problem in the video output of the MVS unit, this problem occurs when you use some mvs board with the Mass supergun. Call up Mass systems on the phone and tell them about your problem, they will know what your talking about and instruct you to send in your board for modifications.

 

[neojedi]

Thanks for the response mainman! The other guy I mentioned in my first post just confirmed that his MVS board works fine in a cab, and since we know that his Supernova works fine, there is definitely a problem resulting from the interaction between the two. I'm going to ask Mass... <IMG SRC="smilies/cool.gif" border="0">

 

[neojedi]

I talked to a tech support guy from Mass. He said that he longer asks people to ship him MVS boards since the problem is on Neo Geo's hardware and it is not the responsibility of Mass to support this hardware. There are, of course, no problems with the Supernova.

But I did get him to tell me that the nature of the problem is that a 100-Ohm resistor on the MVS board between the display pins and the rest of the hardware causes the signal deterioration. So the mod that he was making was just removing that resistor.

I might try this myself, anyone reading this please feel free to inform / warn me of any pitfalls with this procedure. Or question the reasoning.

[ October 12, 2001: Message edited by: neojedi ]