jamma genesis help

A

Airthrow

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Hi guys,

I'm using a genesis model 2 connnected to a new astro city. I've read some people dont need any extra hardware because their monitor accepts composite sync. I have mine wired up, an it displays a viewable picture, but it looks glitchy...there are black bars and flicker, which looks like a sync issue to me.

Does anyone know exactly what chips I need to get the sync proper to display on my new astro? Or even better, a chipless solution...thanks!
 
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Logicdustbin

Logicdustbin

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Airthrow said:
Are you sure the sync cleaner will help? Ordered just now, hopefully it fixes the problem...
Click to expand...

assuming that you have your connections correct, then yes, I can say that this will fix your problems.

BTW - the web site also has a connection guide for the sync cleaner.
 
Hewitson

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I'm not saying that won't fix the problem, it may or may not, but I believe the problem is that the Genesis/MD outputs composite video rather than composite sync.
 
A

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Hewitson said:
I'm not saying that won't fix the problem, it may or may not, but I believe the problem is that the Genesis/MD outputs composite video rather than composite sync.
Click to expand...

There's both a comp. video and comp. sync pin on the A/V connector.
 
Hewitson

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Yes there is, but I believe they're both connected to each other. SCART uses composite video for sync.
 
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grips03

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Gen 1 Genesis has sync output. This is independent of composite video. Gen 2 seems to have sync as well, but I've never checked.
see http://www.gamesx.com/avpinouts/genesisav.htm

My Gen 1 is wired to my Jamma cabinet and just used sync, ground, and rgb. Screen is stable and clear, but washed out.
 
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grips03

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In case you finally get video and its washed out. Move the RGB wires to before (input side) the CXA1145M chip, and before the resistors too. The picture is no longer washed out and looks awesome.

Pics are of Gen 1, notice where I grab RGB, sync and Ground. Wires match the signal color.

http://www.flickr.com/photos/20625046@N08/5524879617/
http://www.flickr.com/photos/20625046@N08/5524879695/

Not to hijack the thread, but will the Genesis blow up or stop working if I power from the jamma harness, i.e. 12v vs. the 10v that the transformer uses?

Also I'm using in Neo 29 cabinet, anyway to make the select button power cycle the Genesis? Idea is to force the Everdrive menu to appear.

Thanks,
Dave

Dave
 
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Hewitson

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I would not recommend 12v, it'd probably be alright but using the Sega AC adapter the heatsink on the 7805's gets very hot as it is.
Connect the +5v from your power supply to the output terminals of the regulators.

I am not sure why you have a hacked pad in there when there is circuits for decoding the controller signals all over the web. At the very least you should have tape on it so it can't short anything out.
 
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grips03

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Hi I removed the DC plug on Genesis and wired in +12v and Ground from Jamma finger board. Everything works. In fact the multimeter measured 13.7v coming from the 10v Genesis power adapter, so +12 from the cabinet should be fine.

Going to try to convert from +12v to +5v, i.e. bypass 7805. When I do this, do I remove the 7805 or cut any traces?

The controllers are mounted to PCB feet with spacers between controller 1 and 2. The PCB feet are screwed to the bottom of the genesis using some of the built in mounting holes. One could shake the genesis while playing and nothing is going anywhere. That being said, if you have a link to bypass the controllers that would be awesome. I saw a schematic on how to build a controller on a PCB, but it used the same parts as the controller, i.e. resistor array, IC, etc.

Thanks,
Dave
 
A

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Hi guys,

I am still having trouble with my Jamma Genesis. I tried taking a video with my cellphone camera of the glitching, but it looks WAY better on youtube than in real life. The colors are fine, but there are black bars and black flickering over the picture. Here is a video, check the Desert Strike letters to see the black flickering I am talking about:

http://www.youtube.com/watch?v=9Wdm6hebsXM

When I tried to hook up the sync cleaner, I lost ALL video. I really don't know what I am doing wrong at this point.
 
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grips03 said:
Hi I removed the DC plug on Genesis and wired in +12v and Ground from Jamma finger board. Everything works. In fact the multimeter measured 13.7v coming from the 10v Genesis power adapter, so +12 from the cabinet should be fine.
Click to expand...

Why do this when you can wire 5V to the "out" post on the power regulator and ground it? This way would avoid extra heat and using the power regulator altogether.

Going to try to convert from +12v to +5v, i.e. bypass 7805. When I do this, do I remove the 7805 or cut any traces?
Click to expand...

There are 5 points on the 7805, the 2 grounds and then the three pins labelled I, G, and O for in, ground, out. Just wire 5V from the Jamma loom to O, and ground to G and you bypass the 7805.

The controllers are mounted to PCB feet with spacers between controller 1 and 2. The PCB feet are screwed to the bottom of the genesis using some of the built in mounting holes. One could shake the genesis while playing and nothing is going anywhere. That being said, if you have a link to bypass the controllers that would be awesome.
Click to expand...

I'd like a schematic for building a 6 button controller on perf board without sacrificing any pads, I have found schematics for the 3 button ones. You can't bypass the controllers altogether because you need the right chip to multiplex the signal, as there isn't enough pins for every input. Here is how to build it:

http://gamesx.com/wiki/doku.php?id=controls:megadrive_genesis_controller_3
 
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grips03

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For your video issue, where are you getting RGB, ground, and sync from? Does the Gen 2 have a CXA1145M chip or similar?

Send a pic of the wires you on the system board and take a pic of the area near this chip?
 
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Airthrow

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grips03 said:
For your video issue, where are you getting RGB, ground, and sync from? Does the Gen 2 have a CXA1145M chip or similar?
Click to expand...

I'm getting it from the underside of the AV connector. But the colors are fine so I'm not sure getting the colors from closer to the video chip would make a difference, what do you think?

It's a Genesis 2, I will check what kind of chip it is tonight.

Send a pic of the wires you on the system board and take a pic of the area near this chip?
Click to expand...

Ok, will take some pics tonight. Do you think it could be a grounding issue? I am assuming it is some kind of zany sync issue, I wish my sync cleaner actually helped but it didn't work...
 
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grips03

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If similar to Genesis Gen 1, then won't need sync cleaner. I have to say on my cabinet Neo 29 (candy sit down type) with Hitachi monitor, that RGB taken before the CXA1145 was so much better its not even funny.

Going to convert to +5 tonight and if that works, going to measure current draw as I'm looking for a normally closed relay, to wire up to the select button. Idea is to force the Everdrive menu when selected is pressed. Or in this case select button on cabinet turns Genesis off when pressed and then on when released. Does someone have a similar setup or a p/n for a NC relay that would do the job?

Thanks,
Dave
 
A

Airthrow

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grips03 said:
If similar to Genesis Gen 1, then won't need sync cleaner. I have to say on my cabinet Neo 29 (candy sit down type) with Hitachi monitor, that RGB taken before the CXA1145 was so much better its not even funny.
Click to expand...

HmmMM, can you post the spots where you got the RGB from before your CXA1145? I will try that tonight, I am pretty desperate because I can't find any info online and so far no suggestions have worked...

Going to convert to +5 tonight and if that works, going to measure current draw as I'm looking for a normally closed relay, to wire up to the select button. Idea is to force the Everdrive menu when selected is pressed. Or in this case select button on cabinet turns Genesis off when pressed and then on when released. Does someone have a similar setup or a p/n for a NC relay that would do the job?

Thanks,
Dave
Click to expand...

I'm not sure if I understand you, but could you use a Happ cherry switch? It has ground on top, the next pin is normally open, and the farthest pin from ground is normally closed.
 
Hewitson

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grips03 said:
Hi I removed the DC plug on Genesis and wired in +12v and Ground from Jamma finger board. Everything works. In fact the multimeter measured 13.7v coming from the 10v Genesis power adapter, so +12 from the cabinet should be fine.
Click to expand...
Measurements taken from unregulated power supplies that aren't under load don't mean a thing. To get an accurate reading you need to have the system running and take a measurement from the input pins of the regulators.

This is all pointless when you've got a regulated power supply which outputs the same voltage that the regulators produce.
 
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grips03

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Ah, makes sense. Yeah I didn't measure the power adapter under load. But it worked non the less. Agree on using the +5, going to do that right now.

Reason for normally closed relay (form b or break relay) vs. a switch is that I can wire to the Genesis and not touch the cabinet, i.e. I can swap to MVS or other boards. When select is pressed I need to have the control circuit get a certain voltage and then it will break the +5 to the Genesis. Hopefully the Genesis doesn't get to cranky when I do this. Going to look for a solid state relay, but need to measure Genesis amp draw to make sure I get a large enough one. Nice thing about relays in that the control circuit is isolated from the load circuit. I know its only 5volts, but oh well.

For a pic of the Gen 1 with good video see my post above with the Flickr URL.

dave
 
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grips03

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Ok wired +5 to Genesis and its now working. I installed a new switch where the old one was so I can still power on/off to swap carts. Didn't bother to monitor the +5 to see how much current is draws. Perhaps on the weekend.

7805
pin I = left alone
pin G = wired to jamma ground
pin O = wired to jamma +5 via SPDT switch

thanks for all the help.

dave
 
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grips03

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installed the NC relay today (Crydom MPDCD3-B). Works well to swap games using Everdrive.


Relay is wired:
Pin 1 (load+) and pin 3 (control+) went to +5 on jammaboard via fuse and SPDT switch. Fuse to protect against short and SPDT to turn off Genesis manually.

Pin 2 (load-) went to output of pin 7805.

Pin 4 went to test switch (jamma pin 15).

Once the "select" button on the Neo 29 is pressed, ground is sent to pin 15 on jammaboard (test), and then to pin 4 of this relay and it disconnects the +5 from the Genesis.

On the negative side the voltage is a bit lower than +5 volts to the Genesis, but it all still works.
 
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Logicdustbin said:
you need a JROK Sync Cleaner.

buy one here:

http://www.jamma-nation-x.com/jammax/store.html (find it under "Arcade -- Hardware")
Click to expand...

This wasn't what i needed. But its okay because I will use the sync cleaner in a supergun I am building.

I got it working after buying the sync seperater chip, and the first diagram i found online did NOT work. I will post the proper one tomorrow when i am not on my phone.

If anyone wants a plug and play JAMMA genesis or SNES, hit me up!
 
Xian Xi

Xian Xi

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Airthrow said:
This wasn't what i needed. But its okay because I will use the sync cleaner in a supergun I am building.

I got it working after buying the sync seperater chip, and the first diagram i found online did NOT work. I will post the proper one tomorrow when i am not on my phone.

If anyone wants a plug and play JAMMA genesis or SNES, hit me up!
Click to expand...

The JROK sync cleaner has a sync separator chip, you just need to desolder the IC close to the edge and tap the outputs from the other IC for separate H and V sync.
 
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Airthrow

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Good to know, but the jrok is way expensive just for that function compared to a LM1881 by itself!
 
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grips03

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I measured the current draw of Genesis with bypass of 7805 and it's about ~380ma. I'm going to wire in a 500ma NC relay vs. the 3A unit I have now. Everything works with the Crydom relay, but its 1500ohm. The Panasonic is only 2.5ohm, p/n AQW612EH.
 
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