Dixie Narco SIID Troubleshooting

[MrVendAlot]

OK I am going to sound like an idiot but need advise.  I have a Dixie Narco SIID that blew a fuse due to connecting a MDB harness when it was hot.  Being an idiot I though the board burnt out.  I purchased a SIID E-boardf to replace it(I think I also just wanted the EPROM upgrade while I was at it).   When I added the new board and installed the bill and coin and fired up the front panel displayed 8888(pretty much all lights on).  The bill validator cycled and would not accept dollars.   When coin were entered they went straight through the coin mech to the coin return.  Then I thought the new board was bad and returned for another(local guy that repairs them).  He gave me the newest unused SIID E board he had.  I went back and got the same error(all lights on with use exact change illuminated).  So then I found the bad  fuse on the original one and installed it again.  It give the standard "." decimal with the "Use exact change" light on.  I tried two bill validators and two coin mechs.  All still dont work.  I went through the diagnostics to be sure MDB was on.  When I do the coin mech check there is no reponse(coin straight through).   Pretty much the board is not signalling the coin mech and bill validator.  

So my question.  I know its the board, not the coin mech, and not the bill validator.  What would cause this?   What does 8888(or similar) mean on the new boards?  Should I start pulling wiring?  Transformer?  Ideas?  

At a loss - Mr Vend Alot

[AngryChris]

It's possible you burnt up the harness.

[Chard]

I I highly doubt it's a burnt up harness.
I might suggest a couple of things. There's a possibility of a bad display as well as a possibility of a bad eprom on the board. I have had bad displays as well as corrupted eproms cause very strange errors on these machines. I suggest pulling the eprom out of the original board and put it in the board that is in the machine currently. It could be the guy that rebuilds boards for you got a bad batch of eproms. If that doesn't work you might try swapping out the display if you have a good one.

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