Coin Op Maytag Neptune Coin Op MAH21PDDWW unknown error code

[Square Deal Appliance]

The first digit of the display is flashing between 1 and 2. The last 2 digits display 28. This isn't even the same format as the error codes on the tech sheet. Anyone have a clue? Thanks.

[16345Ed]

2 hours ago, Square Deal Appliance said:

The first digit of the display is flashing between 1 and 2. The last 2 digits display 28. This isn't even the same format as the error codes on the tech sheet. Anyone have a clue? Thanks.

Typically if unit throws undocumented error the board is wacky. 

[Square Deal Appliance]

I finally figured it out. In case the information is of value to anyone else, there is a switch in the back of the coin box. If that switch fails, or the box is not in place, it throws the error code I described. It does not seem to be in any of the literature.