Strange Touch Screen Issue

[rslots]

Have a 17" Game King with a Ceronix touch screen monitor and the touch screen stops responding intermittently even though the red light on the controller dims when you touch the screen.  Have already replaced the TS controller with known good and have replaced the MPU.  Noticed that when the touch screen stops working you can open the door and activate the mechanical door switch and the touch screen will work but after a while even with the door open it stops working again.  Come to find out that if you touch somewhere on the metal cabinet with your other hand then the TS will always work.  So if you hold your finger on an icon on the screen and get no response then when you touch the metal cabinet with your other hand, it works every time.  Or in other words if you place your free hand on the metal cabinet while playing, then the touch screen always works.  Seems to be a capacitance issue.  Any ideas on how to remedy.  I may try changing the actual touch screen next to see of that works. 

[RB]

I would try adding an aux ground wire to the monitor chassis.

[rslots]

I will try that. I just tried a completely different monitor and same results. Works good initially but after it warms up you have to touch metal cabinet in addition to the rich screen to get it to work.

[rslots]

The resistance between the monitor and the machine cabinet is less than 1 milli-ohm so hard to improve on that. But I did t Rey an added drift ground anyway but no luck.  I thought more about the temperature dependence (gets worse when warmed up). So I replaced the power supply since it is at the heart of all power and grounds and low and behold the problem went away. I have seen power supplies do some strange things but this has to be the most bizarre I have seen.

[Stayouttadabunker]

wow
Was watching this thread to see where it would lead to....haha
I would have never thought it would be the power supply.

I was going to comment earlier and point out that the main clue to this might be...>>>  "...but after it warms up..."
I would of guessed capacitors as well but which ones - I wouldn't know.

Thanks so much for letting us know your fix. 
This may help someone else in the future.