This is a switch-mode PSU, so the mains is rectified to around 400 volts DC inside.

Extra care is required to avoid touching this dangerous part of the PCB.

Instruction manual:

EX354RD+EX354RT_Instruction_Manual-Iss6.pdf

Fault:

Not marked on unit.

Suspected cause:

....

Examination:

...

Action:

...

Result:

....

Status:

Unknown.

Photos:

Plenty of room allows passive cooling:

Front panel:

Power inlet area:

IC8 is an L4981A, a power factor corrector that does most of the control work:

https://www.st.com/resource/en/datasheet/l4981.pdf