hitachi 43fdx01b

i am going to find out why shutdown after relay clicks.all leds are lit on power supply.the green and red dp29 is off after power is appliyed.dp37 comes on and turns off after a few seconds.i know that ip01 pin 5 on primary side is ground.i want to check the HOT and high voltage transistor
qh01.what is a good ground for checking voltage.
on these two transistors.i know tuner shield is sometimes used.my iso transformer is on the fritz.
Edward