I had this within a aracde in Morecambe and Blackpool
The one in Morecambe being Pleasureland Arcade where the 3 player party time deluxe (Player 3) would keep flashing in attract more whilst playing it as Players 1 and 2 didn't attract when you played them, told the staff/engineer about it and they said that it 'should do that' and I went 'No it shouldn't, so they did a test on it and found out that it wasn't connected to the top box and they believed to think a 'Machine Light Bulb' would fix it when infact we all know it wouldn't, so after about 30 minutes of trying to find the problem, they said that it was connected to the top box and surprise it wasn't when I went to play it again, so had a argument with them and they told me not to come back unless I say I was Sorry., in which I won't be doing!
I believe some arcades try to fleece you and make you feel dumb when you know what machines should do even after playing them for over 15+ years.
The one in Blackpool being Star Attractions (aka Mr. B's and Golden Mile), went to play the 3 player stand up one, fairly 1 and 3 went up without a problem and surprise, it was Number 2 that was in attract mode this time whilst playing it as I put around £30 through it and had a talk with the staff there and they said that they would look into it as the technician came out and managed to sort it out and they gave me my £30 back after looking through the CCTV and seeing that I had been playing it.
Went back to the day after after it was fixed and it went up like crazy (Hot Streak), must of had about 50+ boards within £10 and emptying just nearly £140+ out of it (after they refilled it when it was empty).
Went back the day after that to think it might of died down, but managed to get another £70+ from it.
As I know that when these are in attract mode and don't do tops when they should then they would save up and go on a run when they are fixed/connected to the top box.