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scrappysphinx
14th December 2013, 01:35
Hi all, just wondering if anyone can offer any assistance.

I have a Megadrive II here which refuses to go left or down. Up, Right and all buttons seem to work fine. I have tried 3 controllers and they exhibit the same behaviour on this machine but all 3 work perfectly on a different machine i have.

So anyone have any idea on what to check?

Thanks

BluesBrothers
14th December 2013, 01:46
Hi all, just wondering if anyone can offer any assistance.

I have a Megadrive II here which refuses to go left or down. Up, Right and all buttons seem to work fine. I have tried 3 controllers and they exhibit the same behaviour on this machine but all 3 work perfectly on a different machine i have.

So anyone have any idea on what to check?

Thanks

Most obviously the connectors on the MD. I have had to change these on many an occasion because of damage but also they are really prone to solder joints cracking

scrappysphinx
14th December 2013, 01:50
Hi mate, I've tried resoldering the connections, I guess I can try replacing the ports completely

BluesBrothers
14th December 2013, 02:10
Damage to the ports is usually fairly easy to spot, though I would recommend total removal of old solder rather than reflow or addition. this way you get to check the pads.
This area gets a lot of stick and conts may have been quite roughly inserted and pulled over a long period. The next move would be to try some continuity in that area from the connector back. It would come as no surprise if there were a crack in that area

scrappysphinx
14th December 2013, 23:01
No go sadly, tried removing the ports tonight and intalling ones from a working board and still the same behaviour. Got the multimeter out and there is continuity on all pins.

Everything works except left & down. This is same for both players 1 and 2 (tested with Sonic 2). Followed the trace to the via and then on top of the board from the via to the asic and there is definate continuity to the asic.

Any other suggestions or has the asic suffered problems?

Was just testing on Sonic again and he stopped running, seems i've now lost right too :(