Having a problem with my Comet GI circuit. When plugged in, no GI's working at all. My Comets power supply board connector at 3j9 was burnt a bit or had been replaced. I fixed this and noted above a fuse is installed in the board where other Comets power supply board I viewed on line had just a jumper wire installed. This fuse appears to be factory and not installed by someone. The manual shows no fuse suggested. I started out with a 5amp in this location and it blew quite quickly. Tried a 10amp and the GI's did work, but the fuse did get a red glow to it.
Checked the manual on these two lines coming into this board and it states that they are to be 6.3V AC. Checking these two wires incoming power to the PS board, one side shows 6.3 to 7V AC and the other is almost twice as much. It tested at 11 to 12V AC.
So the question is, do I have a bad transformer? Never had this problem before. If so I do have a parts machine of a Bally Kings of Steel. Since this machine is only a year older, would the transformer for this machine work in the Comet if this is my problem?
Lastly, once I get this repaired, what size of fuse do I use in the board for the 6.3 AC circuit?

Thanks for your help.

Mike Willett

OK, did that and it tested 6.84V A/C. So I would assume that this is OK then. Question again, I did have a larger fuse in this circuit as stated above and it did short out at the right terminal of the fuse (20amp fuse). This did take many hours to have this happen as I don't have the machine on for more than 6-8 hours or so when the boys and I are playing the machines I own. Is there another problem or did I just not have a good enough connection at the fuse? Replaced the fuse end with a new terminal, but have not tested yet as I would like to know what size of fuse should I use in this location? Your suggestion?