Model 40x Wms: "Game Chnge 2" error (RAM Clear) - repost

[cfh]

reposted from old NLG site...

To fix the "Game Chnge 2" error on a model 40x williams slot,
the game will require a "RAM clear". This means you'll need a
RAM clear EPROM (27010). These come in different denominations
(5 cent, 25 cent, 50 cent, $1). I just use a 25 cent RAM clear chip,
because all my games are 25 cent machines.

Williams model 40x RAM clear procedure (by statfreak, edited by me):

Try this first: Turn on the machine and let it boot until it states "6AnnE CHn6E 2".
Open the door and press the red diagnostic button. If the display changes to CLR
or the machine reboots and then displays "clr" you're done. Most likely this will not be the case.

If you press the diagnostic button and "6AnnE CHn6E 2" changes to
"nEEd clr" then you need to use your RAM Clear/Denom chip.

To use clear chip:

Turn the machine off.
Open the CPU door.
Remove the CPU board (the bottom board).
Remove XU3 and replace the chip with your 25 cent clear chip.
Replace the board - make sure that it's pushed all the way in and seated correctly.
Close the CPU door.
Turn on the machine.
Wait for it to do it's "thing" which will be next to nothing. 

You should see the denomination in the LED display (25). There is nothing you need to do.
Once the denomination is displayed power down the machine.

Open the CPU door.
Remove the CPU board again.
Remove the clear chip and replace the XU3 data EEPROM.
Replace the board and close the door.
Power up the machine.

You will either see the message ""6AnnE CHn6E" followed by "clr", or you will just see "clr".
Press the red diagnostic button to reinitialize the machine. The machine should shut down
and reboot, then should display "clr". Press the red diagnostic button again to clear the message.

The machine should be ready for play.

The way these machines work is that the backplane board has a set
of security EEPROMs that hold the data for the installed game. If they
do not match the EEPROMs on the CPU board at startup the machine
will not play. This is to prevent tampering. The Clear/Set Denom chip
actually clears the data in the backplane and prepairs it to receive new
chip-specific information (as well as setting the DBV denom). This preparation
only works once. The next time the machine is powered up the backplane
reads the data from whatever chips are installed and stores them, mating
those chips to the machine. The only way to change the chips again is to
use the clear chip again.