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**Reel Slots** Gaming Machines => Bally Reel Games => Topic started by: slcjeeper on March 26, 2020, 09:14:56 PM

Title: Troubleshooting Bally 5500 MPU Need schematic
Post by: slcjeeper on March 26, 2020, 09:14:56 PM

I have a Bally 5500 that a group of deck lights have lost power. Initially the failure was the voltage to these sockets went high and blew all the bulbs, but now there is no power to them. The MPU Board is a 3356-201 Rev J. I found the schematic below, but the componet IDs do not match my board and before I begin probing, I'd like to find a road map. All items in the red circle have lost power. Visually I do not see any damage and all the resistor packs look good.  If anyone can provide some help or a schematic, it would be greatly appreciated.

Title: Re: Troubleshooting Bally 5500 MPU Need schematic
Post by: Badbaud on March 26, 2020, 10:39:47 PM

Do output ports 1 or 0A produce a visible output or is just the top port that doesn't work?

Title: Re: Troubleshooting Bally 5500 MPU Need schematic
Post by: slcjeeper on March 26, 2020, 10:45:30 PM

The other outputs are fine. It's just this one output with the issue.

Title: Re: Troubleshooting Bally 5500 MPU Need schematic
Post by: Badbaud on March 27, 2020, 06:58:13 AM

Then it is probably a defective 8 bit driver chip 273.

Title: Re: Troubleshooting Bally 5500 MPU Need schematic
Post by: slcjeeper on March 27, 2020, 10:40:34 AM

Thanks!  I'll look for that put circuit and update my progress.

Title: Re: Troubleshooting Bally 5500 MPU Need schematic
Post by: Badbaud on March 27, 2020, 02:26:17 PM

LS373 is a better, newer, update of that chip.

Title: Re: Troubleshooting Bally 5500 MPU Need schematic
Post by: slcjeeper on March 27, 2020, 02:31:23 PM

Do you have a preference of plastic or ceramic?

Title: Re: Troubleshooting Bally 5500 MPU Need schematic
Post by: Badbaud on March 27, 2020, 05:40:15 PM

Plastic or paper will work.