TM-D700 fire up issue


I own a TM-D700 for long time. I always keep the unit switched on. Switch off will be taken place by power supply. When I switch PS back on, in the past the TM-D700 came up again. Now, suddenly,  it will not power up. I have to manually switch it on. Then it fires up.
Does anybody have any idea what causes this issue? 
Thank you for any help.

73 de 
DF8FS, Gundolf

Join to automatically receive all group messages.