This display means that at some point the main board lost power from it's back-up battery. It doesn't necessarily mean there is a big problem. However, you can not reset the head hours. This can only be done by an ADAT tech that has a special eprom for this purpose. The unit will not count head hours until this is done. Units that went to the factory with this problem would have the head hours reset according the number of errors that were being written to tape while in record mode, a guess was made based on the number of errors being written to tape. Format a fresh tape and then look at the number of errors(check the manual), if you see 1 or two every few seconds you are probably in good shape. Anything consistantly higher than 20 or 30 I would be worried about.
