After Power lost inhouse, HP 4155A power down and no action.
since some year SMU-5 41501A was defect and unrepaired from HP.
looks inside and tested the power supply.
Fuse are ok.
after long search, i began measure in power supply point for point to check how ends the power and i found that under the ceramic resistors (red marked), glued an thermalfuse. after changed
And for me lucky day, the power supply for 41501A are mostly the same and found the same fault.
power supply 41501A
finish