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


I neveruse thepowersupply to power on/offense radio, many because of power supplyspikesat startup. That can damage a radio. Use radio power on button, that's what it's for! Just my$0.02