700 watt panasonic m/w taking 4 minutes to boil a cup of water ,where it used to take 2.5 min. installed new magnetron, made no difference. any ideas?

hi Gene .how do i confirm that the hv transformer is problem?

Hi Gene .i did some additional testing on this m/w ,checked various levels of power ,on level one m/w cycled on +off every 10 seconds or so, on level 2 it cycled on +of every 15 seconds .but from level 3 to 10 it ran continuosly .at all level it showed 150 volts give or take.i had a cup of water inside.it does boil after 3 1/2 minutes on levels 3-10 .there is no recognizable capacitor in this microwave . the transformer is combined together with a circuit board , there is the control board another smaller board and the transformerboard/ i checked for voltage to trans former with wires atatched ,there is a new magnetron ,the unit has 700 watts. thanks