MSO2024B Blinking screen

I think there is a problem with the power supply module of my MSO2024B. The DSO will power up sometimes and sometimes not. When the DSO is powered up, the screen blinks

Please contact Tektronix service team directly. Below you can find the contact information for our Service Department and someone will be happy to help:
Tektronix/Keithley Repair/Calibration:
Web: https://www.tek.com/en/service-quote
Email: rmarequest@tektronix.com
Calibration services for all other products:
Web: https://www.tek.com/fastquote
Email: mvs@tektronix.com