I have a game here with a transformer and last night over a few beers we were playing the game (Bally SS)and the lights went a  little dim,then a mild hum,then all power went out.I don't see anything with fuses blown.The varistor looks intact,cord is ok.Should I run this game without the extra transformer?

yes you should. Remove that POS

OK..........sounds like these things have a bad reputation.I did a little more checking on the machine and I have power at the service outlet but no power in the boards.I am thinking that the on/off switch is burned up inside.Anybody else have this happen?One other thing is that this machine has a push button not a toggle switch.To replace it with a toggle switch does this toggle have to be a 120 volt rated toggle switch?

Fuse at F6.............blown................looking at the power cord

The Hydro transformer is ahead of F6 and of the machine's power switch;
if you have power at the factory AC outlet in the machine, then the originally
added hydro transformer is most probably good.

I never remove those, they very rarely cause a problem on those early
solid state machine, but they are not really needed  providing that the
AC ground is OK from the prong on the plug to the wiring inside.

For which game is this?
Bobby Orr Power Play, Nitro Ground Shaker, or 1978 Star Trek ?

If F6 is blown, it indicates that there was an overload on the primary
or secondary of the machine's power transformer.

Do all the fuses have the proper rating ?
(e.g. an overfused F4 for instance may not blow if the bridge rectifier
shorts, but it would take the upstream F6 fuse if F6 is not overfused).

Cheers,
- Sylvain.

Quoted from sylvain

The Hydro transformer is ahead of F6 and of the machine's power switch;
if you have power at the factory AC outlet in the machine, then the originally
added hydro transformer is most probably good.

I never remove those, they very rarely cause a problem on those early
solid state machine, but they are not really needed  providing that the
AC ground is OK from the prong on the plug to the wiring inside.

For which game is this?
Bobby Orr Power Play, Nitro Ground Shaker, or 1978 Star Trek ?

If F6 is blown, it indicates that there was an overload on the primary
or secondary of the machine's power transformer.

Do all the fuses have the proper rating ?
(e.g. an overfused F4 for instance may not blow if the bridge rectifier
shorts, but it would take the upstream F6 fuse if F6 is not overfused).

Cheers,
- Sylvain.

This is for the Eight Ball that I got from Gory.........we have been playing the game for a month.....no problems,then last night poof?I will re-check the fuse values and see what I find

Yep,you were right,,,,,,,,,,,,,,my own fault I should have checked them all.Fuse F-4 blows when it has the correct fuse in it.............time to change the bridges

Could also be a drive transistor short on the Solenoid Driver board
(and an associated possibly burned coil now).

Quoted from sylvain

Could also be a drive transistor short on the Solenoid Driver board
(and an associated possibly burned coil now).

It could be as simple as a broken wire on one of the flipper coil lugs or a broken/improperly adjusted EOS switch. If the EOS is out of adjustment, hitting the flipper will cause the GI lights to dim for a second and then F4 will pop.

The F-4 fuse blows as soon as I turn the game on.But now the f-6 is ok and the GI's stay on.I will change to a known good power supply.

I changed  the power supply/rec.board and the machine fires right up.I checked the fuses first this time.The only thing wrong now is a bulb that won't work.I changed the bulb,socket,scr,resoldered the ground and the one bulb still won't work.Funny it worked yesterday before the power outage on the machine.