Mark Levinson ML-9 amp help needed

Hi

Recently I bought this ML-9, and it seems to have a problem. When I turn it on, I can hear something click inside - relay? But the sound comes on right away with a slight thump. When I turn it off, again I hear a click, but it continues to play for a couple of seconds, then the sound gradually diminishes. If there is no signal, right after turning off fir a couple of seconds nothing happens, but then in the left speaker there are very audible thumps, about two per second, for a few seconds and then they go away. I think its putting out DC at that moment. How does that on/off switch is supposed to work? In my Classe DR-9 there is a turn-on delay of about 5 seconds, and at turn-off I can hear the relay click and cut-off outputs completely.

Any help appreciated.