Check the Obvious First
Cash Registers can be very nondescript in their error Reporting and will almost always be accompanied with an ear piercing alarm that will not go away - Press the Clear Key
1/ Check the Machine has Paper - Sounds obvious but this is the most common error condition - After the Paper is changed you will probably need to press the C or Clear key to clear the error from the screen
2/ Check that the last sale has been completed before turning the mode keyswitch to another mode, and avoid pressing every button on the keyboard to try and clear it
3/ Check the manual for error codes - This at least will give you a place to start looking
4/ If you have a key mode error, then you will need to return the key to the previous position and complete the transaction. This may have been X or Z mode, in which case pressing the Clear key followed by Subtotal or Cash should clear the error.
5/ Check your Printer for a Paper jam, Ribbon Jam or debris stuck in the printer
6/ Almost all Cash registers have a Program Reset, Flag Clear or non destructive reset procedure which will clear operation errors, and reset the program to a ready to go state. This is a safe reset procedure and will not destroy any programming data. - You may need to sign on a clerk or press clerk button after a program reset
7/ Call your Dealer - Dont do a full RAM Clear unless you really want to start from scratch and create a lot of work. Over 99% of cash registers are repairable or recoverable as long as you do not do the Factory Reset
8/ All Cash registers will have a RAM Clear or Memory All Clear sequence which will ERASE all your program data, Machine Totals, and all Counters. This is a destructive process and returns the cash register to factory default. This procedure is not reversible. On small Cash registers with little programming this is not important, However with programmable Cash registers that have Receipt Logos, Programmable Names and Prices, there will be a major cost in time or money to recreate your custom setup. If you have a backup of your program this may save time in setting up the till again but it will still be an extra inconvenience.