Author Topic: I need help with my sega genesis, please  (Read 2125 times)

Offline Stormy

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I need help with my sega genesis, please
« on: December 20, 2007, 08:17:47 PM »
Hi everybody,

In my latests project I have taken apart a sega genesis and I took the pins off the board so that I could relocate them to a new spot, I used a ribbon cable to reattach them to the motherboard.  I have done this so far to three sega genesis consoles.   After relocating the cartidge pins for the first two systems I tested out the systems and both times I got a black screen. 

On my latest attempt, the third console (Genesis 2), I simply soldered the pins from the second console to the back of the third consoles pins so that both sets of pins are usable.  If I put a game (sonic the hedgehog) in the added on set of pins the "liscenced by sega" screen appears like normal but then the screen goes black.  Then if I put the same game in the orginal pins it works fine. 

It sounds like a simple loose wire problem or cross over problem but I have scanned over the connections so many times I have lost count.  I have relocated the pins on many other systems with no problems the sega is the only problematic system.  Does any one have any ideas as to what the problem could be with the genesis? 

Thanks

*EDIT*

Okay, so I finally figured it out!

It turns out that the ribbon cable is rounding the ends of the digital signal, making it look more like a sine wave.  On top of that the ribbon cable is allowing for the signal to be reflected back up the wire which causes further interference to the original signal.

There are two ways to solve this, one is to try and use as short of a ribbon cable as possible and the other is to actually engineer a solution.  Engineering a solution involves me researching transmission lines, cable impedence, and using an oscilloscope to look at the digital signals.

I will hopefully be able to post the solution soon

Indy: Edit your post don't double post.
« Last Edit: February 12, 2008, 02:40:05 PM by IndyChav »

 

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