Touch screen communication failure and Bill Validator Comm Failure

[xpin]

Hi all,

I want to ask for suggestions on here before I buy more replacement parts that may or may not fix the issue.  I have a IGT Game King round top flat touch screen 004 main board version.  I am getting a "Touch screen communication failure" and "Bill Validator Comm Failure" messages that go away and come back within a few seconds.  I re-chipped 3 times now and the result is the same.  I can barely make it through the setup because the touch screen works intermittently and when it does work my touch is off about an inch from where it registers. It gets worse the further left I go it seems. All while the bill validator cycles every 10 - 30 seconds.  After it boots I get the 2 error messages mentioned above.  I pulled the BV and still get the touch screen error intermittently.  I was able to get to the screen calibration where it says push the dot until a sound is heard.  However I touch there and nothing happens.  I tried several times holding the touch about 5 minutes before giving up.  I tried swapping the touch screen controller board with a know good board and am getting the same results.  From what I've researched other things to try are a new power supply or netplex board.  Any ideas on what's going on here and how to fix?

Thanks in advance for any help.

[lookes]

The three NETPLEX devices in your machine are the bill validator, the printer, an the touch screen controller. If you have a hopper it can also cause NETPLEX problems. Pull it out.

Disconnect the BV, and printer at the backplane. You may get a BV error but the touch screen will work normally if it was one of those two devices. The riibon cable or coil cord that allows the printer to pull out often gets damaged and shorts NETPLEX signal lines.

All that is left after that is the backplane, and MPU. I have not seen this happen on an 044 MPU but it does happen on 3902's.

[hotlsot]

does this machine have a uba bill acceptor?

[xpin]

I disconnected the BV (it's a MEI) and ticket printer from the backplane, neither had any effect.  There is no hopper in this machine. I checked the pins in the 2 ports on the back of the motherboard and none of them are bent.  I don't have a spare backplane readily available to swap.  I can ebay one (or is there another place you'd recommend for parts) and give it a try if that is the next step.

[lookes]

Do you have another cabinet to try the MPU in?  Check the wiring harnesses for damage.  I don't think it would be the power supply but if the 'power good' signal is cutting out, I don't know what kind of error that would cause.

I can test the MPU and backplane if you don't have another way to do it.

[xpin]

I don't have another machine to try it in.  I was messing around with other diagnostics and noticed in the "QUARTS INPUT" screen that both "COIN DROP DOOR" and "POWER SUPPLY PULSE" are rapidly switching between 0 and 1.  Is that normal?

[lookes]

That is normal.