Replace bad voltage regulator with another one that have lower output current
It depends on what the actual load is.  If the load really draws most of the 150 mA available from the existing regulator, then you can't replace it with a 100 mA regulator.  If the load only draws 100 mA or less, then a 100 mA regulator is fine.

I just looked and the TL750L05 is a linear regulator, as the name hints.  It is not a SMPS (switch mode power supply).  However, the answer about a replacement is the same.  Either way, you have to make sure any replacement can provide the current that the load needs.  You have to start with finding what that is.