### MP-064 APL checksum error

An APL control EPROM appears to be present on the Temperature Compensation board, but the computed checksum failed to agree with the memory. This may occur at power-up or during any system initialization.

What you should do

1. To clear the error, click Clear error in the XYZ Display window. To clear it using an RCU-II, press and hold down the Servo Power Off button and then press the Joy button twice.

2. If the error reoccurs, call your Giddings & Lewis service representative.