Plug into different circuit. Got to have stable 120v or can reset. Things like Air-conditioning compressors kicking on or other high current loads can drop line voltage.

Have him check the coil diodes. A loose diode could cause resets, especially the flippers during multiball.

Might've come loose duringvthe move.

You may have a low 5v, check your power supply and maybe rebuild the 5v section on the power supply.

This may help to from pinwiki

System 9/11 games are far more tolerant of low line conditions vs. the newer WPC games. Some things to check if the game is resetting are the usual culprits for this type of thing: connectors, filter capacitors, slam switches, bad chip sockets, etc. It is good preventative maintenance to replace the +5 volt filter capacitor on the power supply with a new one; most of these are between 20-26 years old and might be getting to the point of wearing out. Certainly replace them if you are getting resetting on your system 11 game.

Most system 11 games give an indication that they've been slam tilted; if you're getting a "game reset" but you get a noise and/or a message on the displays beforehand, it is probably a slam switch issue vs. a true reset issue. Check all the slam switches in the game (usually the coin door is the main one, and also the ball roll tilt if present).

Thanks for the posts! I'm the new HS owner btw. ;o]

The machine will reset randomly, and it doesn't matter whether the game is being played or not. It's been moved to several different outlets on different circuits with no difference. The current circuit it is on is a newer circuit that is only being used by a TV, two lamps, and some other pinball machines. Nothing is currently on, just the one pinball machine so nothing is drawing power except this machine on that circuit. I have to eliminate this as an option.

So according to your description, it's not a slam switch type of reset. It just reboots, no message, just right back to the start. I do get a "ding" sound when it reboots, but I also get this when just turning the machine on. Slam tilt or just normal boot sound? maybe I'll make a video of this..

A couple of things you had mentioned I will check, such as the 5v power - if there is good documentation of how to check this online, can you point me to it? I'm not very electrically savvy in the pinball world, so I have some learning to do.

Coil Diode's - where are these? Keep in mind, it's not going to be anything mechanical (since it happens when the machine is just on and sitting there).

Al- btw, I fixes all of the switches, everything works - the left ball launch is still randomly triggering; it always triggers when you first turn on the machine about 6-8 times then stops, and randomly during play it will trigger about 6-8 times. weird, not sure what is causing this.

The dim lights (more they do not work) are definitely caused by the ground plate and/or the wire that grounds it. I was able to bridge it to another plate and make them all function correctly, though I removed this and will properly diagnose the problem.

thanks for the help everyone!

Diodes to look at: pop up the playfield and look at the flipper coil diodes and pop bumper diodes. GENTLY pull on them and see if they're attached well. A loose diode (or a faulty one at that) is a very common reason for a reset.

However, as you say this even resets during non-use, I question the problem being a diode. BUT, nonetheless, pop up the playfield and check the diodes.

If it's rebooting like that, it's definitely power related. Something is probably causing supply power to droop to the system board causing a reset.

Thoughts:
Does the dome light work? Is it power cycling in attract mode when the dome lightsor is supposed to light? Try cycling the dome light in the test mode.
Does it work fine for maybe 10-15 minutes, then reboot? Does it reboot on a regular time interval?

I haven't gotten a chance to work on it yet, but I'll answer shpwizards questions:

Does the dome light work? yes it fully works

Is it power cycling in attract mode when the dome lightsor is supposed to light? Try cycling the dome light in the test mode. Power cycling as in does it reset - no, the dome light does not trigger it to reset. All lights seem to function normally and do not trigger anything.

Does it work fine for maybe 10-15 minutes, then reboot? Does it reboot on a regular time interval?
I was timing this to see how long it would take. At minimum it would be about 6-7 minutes, sometimes longer, up to 15 minutes - I wanted to determine if it was close to an exact time, say, if attract mode was causing it, but it was fairly random.

I hope you get it worked out. I disabled the police light to run during attract mode. Only to run during game play.

I got a chance to play around a bit with this yesterday. I've checked all of the connections behind the headboard, and I am pretty satisfied that it is not back there.

When the game is first turned on, the right launcher (that kicks the ball out to the flipper), will trigger about 8-10 times. When the game does the reset, it will also cause that launcher to kick over and over about 8-10 times. It will do this randomly as well, so it's not just specific to the reset.

The reset is also seeming to be the same as if the game were slam tilted. Makes a ding, and goes back into attract mode.

Does this mean anything to anyone? ;o]

Attach a DMM set to VDC and monitor the 5 VDC. First let us know the Voltage you are measuring and second, see if this voltage drops at all when you get the reset. It also would not hurt at all to replace the 5VDC filter cap. I would do this right now.

I would disconnect one wire going to this coil and see if this makes a difference in your random resets. But again change the 5VDC cap, it can't hurt and can only help. Good Luck

Did you remove the head when you transported or moved the game? This could be a simple connector problem. I would double check the connections. It takes 5 min. Don't overlook that.

If not, it's most likely a broken, missing or reversed diode (mistake from previous repair). Turn power off, pull the glass, take the balls out, lift the playfield.

Inspect all coil diodes, with power off, (especially the 3 flippers coils) ones that see the most action and force. Don't forget under the apron. The ones that are firing at random would be the place I'd start first. They can break loose from constant firing. Check the switch contacts for those as well.

t/s diode resets could be time consuming. Issues can be easily overlooked and people starting tearing into other sections. On a old sys 11 game resets, I think it's best to replace all coil diodes. Pick em up at the shack, their cheap and you can knock all of them out in 20 min. If done right, you never have to go down this road again, and second guess yourself if it's a bad coil diode causing a reset.

If it's over your head. Bribe a tech with a case a beer on your way to the shack. He should be able to show you what to do or have it fixed in 10 min. Always better to learn hands-on from someone when you're new.

Report back when you find the smokin gun.

Good advice in checking under apron.

I would bet money it's low voltage at the power supply. I am a system 11 nut, and 3 of my 4 system 11s have had this same issue. The system 6 was doing it too. Check the voltages. There is a transitor that regulates the 12 volts attatched to the BIG heat sink in the upper right of the power supply. It could be that (not likely as low plus 12 usually causes resets under load, like when playing), check the test points for your +5 volt logic supply too. It is most likely that since you are getting random resets during non use. The +5 volts can be low because of bad capacitors. Replace all the big caps on the psu and you'll be good for years. The rally big one is 15000 or 18000 microfarad and 35 volts. The other two smaller ones on the left escape me at the moment, but they are printed with their rating.

You need to get a multimeter and check voltages. Would you go to your doctor, complaining about chest pain, and be happy when he just decided you needed a heart bypass? No, you would expect him to run some tests and determine why you had chest pain

Using a multimeter can be intimidating, but it's really not hard. This video is excellent, for the basics...