The first place to look is the flipper coils and diodes and then the power supply filter capacitors. These are well known to cause exactly what you are describing.

Try cleaning the contacts first. The EOS contacts could be arcing and sticking. I've seen this in my Medusa on both sides. Replace the diodes before the coil(s) as they are alot cheaper. Just get some 1N4004 diodes or take one off an old part and try it.

A shorting capacitor in the power supply. The capacitor shorts then discharges and there goes your power until it recharges and returns the power to a usable level. That's my guess .

If it were an old Bally/Stern I would say that one coil stuck on is probably the corresponding transistor on the solenoid Driver board. But I have never done a Gottlieb.

"frying" ? Do you see smoke? and if so, from where? You can try disconnecting the problem switch and boot the machine and see if the problem happens again. Keep in mind that if your machine has diagnostics it will detect the disconnected as bad or broken circuit. The process of elimination...

I'm constantly having the EXACT same problem with this Gottlieb Torch which is from the same design. It again won't recognize any of the door switches including the start switch, diagnostic switch, or credit switches. It is not any of the IC's on the Ni-Wumpf board as I replaced them all several times this morning and it's still a no-go. I can see that the voltage on Pin 39 of the 8279 IC is not going to near zero volts when the ball is placed in the trough. It's going from 5.2 Volts to 4.75 Volts. I will try cleaning the contacts as one last WAG. It could also maybe be a grounding problem but I'm so sick of this machine. I doubt I will ever again buy a Gottlieb system 1 machine. At least I only paid $90 for it.

I think it's getting consigned to the workshop in the garage. I'm bringing in the Street Fighter II and the Circus Voltaire today from there.

Edit: It's working again after more tinkering but it's still going out to the garage later.

Machines always start to work once they know they are getting put out to pasture.

Letter K .. I can help .. First let me know what kind of boards are in it. Does it have a replacement CPU board or the original ? Same with the driver board. Mine has both as replacements. (Both the old ones do work and have been repaired but I don't use them).

Feed me some more info so I can help you get it running. Mine had a fried outhole transistor and solenoid when I bought it.

There is a small "lockout" wire on the coin slots. If it's at all touching the metal of the switch the game won't take credits. The lockout coil/bar is always supposed to be energized pulling them away. Mine I just bent away and de-energized the lockout coil. I didn't like an always on coil.

Also the slam switch on the door needs to be "closed" as well as the switch on the side of the cabinet with the ball(s). For some stupid reason Gottlieb made them that way instead of making them normally open.

http://www.flippers.com/servicing_the_gottlieb_system_1_.html#dead

you might find something on this page?

SealClubber is right .. now that I had destined the Torch machine to the garage workshop oblivion it won't break down. I've tried it over and over for hours including resets and power down/power ups. One day last weekend the dang thing blew up just sitting there powered on. Not only was it not recognizing all the coin door switches it was constantly blowing the 2A slowblo fuse for the drop targets etc.

So I guess these machines do have "feelings" and need to be threatened to "behave" ??

Hmmmmmmm

I found this page quite helpful. It also has the Gottlieb System 1 schematics for download.

http://tuukan.fliput.net/sys1_en.html

I ended up putting a 12000 uF 75V filter cap in mine for the 5V feed. It's a large off the board mod but it should provide more than enough filtering and protection.

If you're friend messed with the slam switch it's time for that WWF style body slam !

You can go bigger, just not smaller, but it isn't necessary. If they're out of the size you need but have one larger that works then I would get the bigger one.

Thats right
'The bigger the cap the harder they fall'

What coil on the bottom of the cabinet ?
the coil on the coin door?
http://www.pinrepair.com/bally/index1.htm#coils
this sec. on coils might help
also check the diodes on the flipper coils use your fingers to see if they are broken
that may add to resetting problems

I sent a Private Message to inform about the steps i would plan alone.

Guys , are you all OK to use this strategy i have given ?

- check voltages on powersupply "cold" and "warm after some minutes" without boards connected.Take care about ventures of J2, and J3 .
- check coils disconnected (and diodes - Right ! Autumnfade ) , and check transistors linked to these coils . Fix it if necessary.
- Try powerSupply + CPU . Let's working some time.
- Try powersupply + CPU + Driver.

You should do a continuity test on that coil, to make sure the coil it's self isn't grounding out. If that's the only part heating up, it stands to reason...

You know the only other coil thats low in the cabinet is the 'Knocker' I could see if a credit wheel (EM) was all crusted up with oil and carbon how it would jam & not return keeping the knocker coil 'on'.
I once found a Chime unit on a GTB pin that had 2 of the 3 coils so fried you could see the inside Sol. tube had almost melted closed - all because of a playfield contact was stuck closed and the relay in the back box wouldn't release .
-more things to think about

Those are the main AC power transformers. Most likely the one on the left with all the secondary taps has a shorted winding. It's just enameled copper wire windings wound around with wax paper insulation. You will probably have to get one used from another Gottlieb system one machine. I'd call or email all the different vendors first and see if they might have one or both.

Here is a link to a schematic of those with part numbers (It's the B-19325 transformer):

http://tuukan.fliput.net/sys1_bot.jpg

Good luck ! If you search on that part number I'm sure you will see the discussion on rec.games.pinball where someone else was looking for that exact part too.

These look rebuildable. Look in your local Yellow Pages and see if you can find a electronics shop and get it rebuilt. That just might be a faster, less exspensive way to go. I have a Kunkles Auto Parts in my area that does eletronical work like this, altanators/starter motors/windshield wiper motor rebuilding.

This is right along those lines as far as the rewinding/insulating goes, never hurt to pick the phone up and find out...

I think the Question is WHY,
why is the transformer burning up or overheating ?

It is burning because there is a shorcut !

The fuses are installed to protect all the output of transformer.

So remove all fuses , and check the AC voltages on each transformer output ! (not input)
(perhaps directly on the fuses board)

Take care to HighVoltage. If you're not familiar with this kind of activity , ask to a friend-specialist

I would be not confident with a burnt transformer - and you , Guys ?

And of course , after to determine why it's a shorcut !

Check all the rectifiers and ..

I'm afraid you have to find a buddy to check your cards or in another pin ?
Perhaps, do you have a pinrepair center , just to check ?

Check the flipper coils as they are usually the first to fail because of the high usage. The schematic link should give you the voltages to check for off the taps with the fuses removed.

From Williams System 11 repair guide:

"Any coil that has locked on (usually due to a shorted CPU board transistor) will heat up and could have a lower total resistance. This happens because the painted enamel insulation on the coil's wire burns easily, causing the windings to short against each other. This will lower the coil's resistance, causing the coil to get even hotter. Within a minute or so the coil becomes a dead short (less than 2 ohms), and usually blows a fuse (assuming the game has not been over-fused; in this case it can burn circuit board traces)."

If you don't have this link all ready: http://marvin3m.com/fix.htm. Tons of good info there.

Hi, About your transformer. I work in a electric motor repair shop and we rewind/ rebuild stuff like this all the time. If you can't find one, definately check your yellow pages for a electric motor shop. It might even be cheaper than a new one. Depending on which winding is shorted, wire size, turns etc., with the new insulating materials today. if you had it rebuilt, it would practically be indestructable. Heck, If you were in the Toronto area I'd do it for you. If you are gonna pull it out, Take lots of pictures and label everything. Just so you get the wires back on the right taps.

Yes, I feel save to say it is insulation. You can paint the back area with liquid electrical tape witch can be gotten at most hardware stores. Does the plastic look burnt or melted?

Can you upload a pic?

Well guys i realy dont have the time to read all this so maybe i am saying something stupid.

FIRST! Do the ground mod as discribed in http://www.pinrepair.com/sys1/#ground
SECOND! Then check all the connectors http://www.pinrepair.com/sys1/#connect
THIRD! Do the SLAMMOD http://www.pinrepair.com/sys1/#slam

If you have reset problems on a System 1 this is the way to go. Not the transformer or flippercoils.

Hmmmm, it would be a slick trick to extend the wires and mount the transister remotely. I can see the sholders on the plastic that go into the screw holes so that the screws don't ground out the transister. You can use shrink tube to insulate wires, it works well. Does the transister have a manufacture name and part number?

You can buy a mylar/mica insulator for that. I use them all the time at work. I will look for a pic/link now and edit this post to show that part. That is a TO-3 transistor.