Gottlieb EM Solved EM machine shocks

[ldj1002]

I have a EM Gottlieb pinball that shocks me. Any ideas where to look for the problem.

 

[faralos]

loosed wires near the flipper buttons maybe
hitting the cab itself resulting in shocks
check everywhere for a loose wire touching the side rails of the cab

 

[ldj1002]

Thanks, I'll have a good look see this week end

 

[pinballdaveh]

does the machine have a 2 wire or 3 wire 120vac cord with grounding plug? if the machine has the original 2 wire cord its a good idea to replace it with a new 3 wire grounding cord . the cord comes into the machine and connects usually with wire nuts. the ground wire sometimes will only connect to the transformer mounting foot screw. in addition to that i run a #18-16 gauge green stranded wire from the ground wire to the machines front door frame mounting bolt and nut and the top crossbar latching assembly bolt or screw. then when the top crossbar is latched in possition the side rails will be grounded also. check the switch insulating paper ( called fish paper ) on the coin door switches, reset button, and flipper buttons for worn or cracked off paper. reset button fish paper is important because on some early em machines 120vac was used in the in the reset button switch circuit and may cause a bad shock. new line cords and fish papers are availible at pinball resource and the green wire at radio shack.

 

[ldj1002]

This machine has been at my Grand Daughters for a couple years. I just got it to my house tonight. Will look into it starting tomorrow. The machine does have the 2 prong cord. also she said it would shock sometime, not all time. She said if it would shock it was after playing 20 min. or so and that it is the right flipper button that did it. Will look into it starting tomorrow. What is bad when something is intermittent like this, it just will take time to know if it is fixed or not unless I find something very obvious.

OK TODAY SUNDAY. I can't find anything obvious in the wiring except one light bulb socket is broken from the hold down mount. It could move and get against the metal right under the glass that gives instructions etc. but that metal doesn't touch anything conductive. Besides the part of the socket that could touch would be ground, I therefore don't think that is it. The flipper button had no electrical connection, it is a linkage(lever) that mashes the contact under play field. So I don't see how that could shock. However all around the button is metal so maybe that is what was shocking but if so why only when button was pushed? The AC power cord has 2 wires, one to a fuse then on into a wire bundle, the other goes to transformer, both are soldered. I guess I'll replace that ac cord but where would I put that 3rd ground wire? The transformer is mounted on wood so I can't see how it would do anygood to mount it to one of those mounts.

does the machine have a 2 wire or 3 wire 120vac cord with grounding plug? if the machine has the original 2 wire cord its a good idea to replace it with a new 3 wire grounding cord . the cord comes into the machine and connects usually with wire nuts. the ground wire sometimes will only connect to the transformer mounting foot screw. in addition to that i run a #18-16 gauge green stranded wire from the ground wire to the machines front door frame mounting bolt and nut and the top crossbar latching assembly bolt or screw. then when the top crossbar is latched in possition the side rails will be grounded also. check the switch insulating paper ( called fish paper ) on the coin door switches, reset button, and flipper buttons for worn or cracked off paper. reset button fish paper is important because on some early em machines 120vac was used in the in the reset button switch circuit and may cause a bad shock. new line cords and fish papers are availible at pinball resource and the green wire at radio shack.

 

[pinballdaveh]

on older gottlieb em machines metal flipper buttuns were used. so its possible for electric flow from button thru linkage to the switch. try insulating the end of the linkage at the L shaped bend that pushes on the switch with heat shrink tubing or electrical tape. when installing a new 3 wire cord hook the ground wire to transformer mounting foot for protection if the transformer fails or shorts to ground.

 

[faralos]

personally I wouldn't plug in any pin that didn't have a three prong plug
but having worked at a company that loved to break off the ground plug prong
yes you can play them but if they short out you may be in for a heap of trouble
since that third prong (grounding prong) may short out a major component of the pin
like possibly a board somewhere

 

[ldj1002]

That linkage to flipper button is already insulated with small rubber hose over it. If it didn't come from factory that way then someone has done it in past,---maybe someone was getting shocked before.
I will now put the 3 wire plug on it