5500 MPU board not booting

[pinwizman]

I have a Bally 5500 Sevens that was given to me. Knowing nothing about Slots ( I do know how to repair some Pinball machines) I dug into it. Found the battery dead, replaced it. Bought the clearing chips and was able to get it up and running. Played the machine for about 45min last night. today I turned it on to see which light bulbs I still needed to change. How the machine will not boot up. The lights come on, the bill validator cycles, but that's it. I know I'm getting power to the MPU Board. I have an other MPU Board I stuck just to see if I dad power to the board. Where do I go from here? The red MPU light keeps blinking.

Not sure what I did but its now booting up, however I'm getting a code 31 hopper jamb. The hopper is not jammed??

Thanks Rob

[Neonkiss]

Error should clear by opening and closing the door or just the door switch.

[pinwizman]

I tried that, turned off, and turned on, pulled the hopper out, reinstalled reseating the connection?

[Sunrise Side]

Try clearing it again.

[pinwizman]

It's cleaned, I even swapped out the hopper, Still getting the #31 error, plus I also getting a Code 54. I checked the two switches, the top one was cought on the money tray. readjusted the switch and still won't clear. I tried to do another saferam clear and I'm getting all 9's in the display. I don't know
enough about slots, but I'm thinking RAM problem?

[Sunrise Side]

Have you reseated all the harnesses at the backplane? Check your circuit breakers near the power switch. Reseat all the wires that connect to the breakers. 54 is cash door is open.

[Neonkiss]

Check the switch that is used for the cash box on the right side of the machine. If the lock is missing then the way it use to work was the cam of the lock would close a switch above the outside door. Sometimes you can reach the switch from inside the machine on the right hand side behind the bill validator. It is common for someone to use a folded piece of paper or something under the switch lever to hold it up, but if the paper comes loose it results in the 54 error

[pinwizman]

I'll reseat everything on the backplane tomorrow to see if I can get rid of the code 31. Got the code 54, I put a wire tie around the top switch to make sure that, that switch will always stay close. The bottom switch seems to be Ok. The cash box depresses it correctly. I can't seem to get a good safeRom clear. I do the clear procedure and all I get is 9's in the display. I ordered new ROM's and I'll install them to try to get a good clear, maybe that will clear the errors. Will see what happens then.

Thanks for the help

[pinwizman]

Thanks for everyone help. I re-seated backplane and re-seated all main game chips. It finally did a good ram clear. Cleared all error codes. Problem solved.