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Mickey Juice
16th April 2006, 07:06 PM
Yo!

Just after some help with a problem i've got with my NeoGeo (TMNT) machine...

I can hear the game running fine ie audio but there is no picture. The tube is working, as its glowing, there's just no picture.

Would the probs be with the gameboard / wiring / or the tube chassis???

EDIT: A picture :D

http://members.dodo.net.au/~mickeyjuice12/neofault.jpg

Arcade King
16th April 2006, 07:10 PM
Few things you can try to narrow it down is try another game board on the cab and try your neo board in another cab.
If another board works in your neo cab then you can assume its the neo geo pcb itself and if the neo pcb works in another cab then its something from the harness up .

Mickey Juice
16th April 2006, 08:30 PM
Righto I'll try that.
The actual problem surfaced when:
I fixed a 6 slot MVS, then plugged it in to test it and I had this problem. So I then put back in the original 4 slot, but the same problem continued.
The thing is, I hadnt run the machine for a while before hand, so I should have turned it on before changing the boards... Then I would have known if swapping the boards caused the problem.. or it was gunna happen anyway.

BTW I modified the jamma for NeoGeo ie stereo and game select button, throwing in an original jamma board to try and solve this problem wont cause any problems will it??

Arcade King
16th April 2006, 08:33 PM
Check the voltage at the edge connector before putting any other board in! could be your power supply.

Mickey Juice
16th April 2006, 08:41 PM
What voltage should it be for an MVS?

Arcade King
16th April 2006, 08:45 PM
should be anywhere between 4.8 and 5 volts. But you should have the voltage lower when connecting a board. Just remember once you do connect the pcb and its drawing current and you will have to turn the voltage up slightly to compensate. I always check the voltage on the board itself :)

Mickey Juice
16th April 2006, 08:50 PM
But you should have the voltage lower when connecting a board.

:unsure ? So turn down the voltage before connecting?

Arcade King
16th April 2006, 09:01 PM
nah I mean just make sure the voltage is there for starters :) then set it for about 4.8-5 volts then plug your pcb in. once pcb is in then you can adjust the volts further. I'm crap at explaining thing in text give me a ring if you need me to explain further.

Berty
16th April 2006, 11:51 PM
My MV4F draws 5.2V on load at the edge connector and 5.4 at the PSU.

The 6 slot and 4 slot have hefty power requirements, but i am yet to see one that would even initialize if the 5v was too low. Generally you wont get anything at all if the 5v is too low, but your getting sound? strange.

EDIT,

you really need to test it with another PCB, prefferable one you know that works. I have been thinking about it and a neo geo wont even start if the 5v is too low, so the fact that you are getting sound leads me to believe that the board is functioning normally, but you have got a monitor problem.

Jomac
16th April 2006, 11:58 PM
Looking at that Pic Mickey , you might be out of gas :)

Or somehow you managed to unplug the video lead between your Jamma Harness and monitor chassis .

Savage
17th April 2006, 07:18 AM
I had the exact same problem with my Neo Geo, sound but no display. Turned out to be the monitor board (I think it's called the chassis?)

It was fried, ...

Mickey Juice
17th April 2006, 09:06 AM
hmm, I'll try my Double Dragon board tonight.
I'll pull the machine out so I can get a decent look at the rear internals. I had the problem yonks ago, but then I moved so I never bothered fixing it.
But now I want to play some Puzzle Bobble and Magical Drop II :D

Mickey Juice
17th April 2006, 07:53 PM
TaDaaahhhhh...

http://members.dodo.net.au/~mickeyjuice12/neoworks.jpg

Well don't I feel like a dick... I was about to plug in my DD2 board (Which was about to become a pain, as the jamma harness had a key soldered into it (so it only goes the one way).. and my DD2 board didnt have a slot cut for the key.. thus I would have had to hack out the key from the jamma to be able to plug it in)

Anyhow, I thought I'd check the chassis first ;) So I pushed the cobwebs aside and pulled out the machine... Then I noticed the RGB video cable wasn't plugged in :o A few of the pins were bent, so it looks like when I tried to plug in the 6 slot it yanked out the RGB cable.
I plugged it back in a voila! Magical Drop and Puzzle Bobble games for all!! Nothing like playing real arcade games on huge CRTs. Don't think I'll be converting it back to TMNT just yet, those games are too much fun. Once I get an original NeoGeo machine I'll do it.

The monitor needs to be degaussed.. and it's a little washed out, but it's alive.

So the next thing to do is test the 6 slot board I bought faulty for $50...

Arcade King
17th April 2006, 07:58 PM
The monitor needs to be degaussed.. and it's a little washed out, but it's alive.

nah its just a wells lol.

rottenpig
17th April 2006, 08:56 PM
I plugged it back in a voila! Magical Drop and Puzzle Bobble games for all!! Nothing like playing real arcade games on huge CRTs. Don't think I'll be converting it back to TMNT just yet, those games are too much fun. Once I get an original NeoGeo machine I'll do it.

The monitor needs to be degaussed.. and it's a little washed out, but it's alive.


don't you hate playing puzzle bobble on a monitor that isn't degaused properly! brown looks like yellow, blue looks like purple.

Mickey Juice
17th April 2006, 09:25 PM
heh, there's only one small section where the red looks like brown. Other than that it's ok :)