JVC PD-42WV74 Service Manual page 157

NOTES AT THE TIME OF REPAIR
When the [IN-1] connector which has connected the SMPS PWB and the VIDEO SMPS PWB is removed,
please be sure to measure the voltage value between 1 pin and 4 pin of the [IN-1] connector on a SMPS PWB.
Please connect a connector after dropping on less than 50V, when a voltage value between 1 pin and 4 pin is
more than 50V.
If it connects while the voltage value has been more than 50V, the fuse on the VIDEO SMPS PWB may blow
and it may become the cause of secondary failure.
IN-1
(No.01730B)
2(No.YA029D)