Landed from ATH at 17:27 and according the pilot we were asked to hold short of T5 (we did appear to be overtaken by half a dozen other aircraft). As we eventually moved towards a gate I could see the orange guidance display wasn't on, so I assume that's the reason we were waiting a couple more minutes before pulling up to the stand. Then took another 10 minutes to find someone to connect the jetty. The pilot (or FO) blamed a systems outage.