For those saying younger people don't have CC cards or ATM cards....PLEASE, they couldn't buy a ticket without a credit or debit card. NOBODY should have to carry $300-$1000 on their layovers and THAT is reason enough to go cashless. The only people who will REALLY miss the cash alternative are the thieves.
As far as the HHD? If our stupid flight attendant group would just once read their company mail, a memo, or visit Wings, they would KNOW how to troubleshoot with the HHD. There is NO EXCUSE for the STUPID scenerios I have seen. How about checking the batteries to see if they are low. Soft setting. Transmit. Wow, what concepts. If everyone would transmit and not let the darn thing accumulate a week's worth of sales, there wouldn't be many issues.
I promise you between Brinks and stealing, we will profit A LOT the moment we go cashless!