[Seek Help] MKL02Z32VFM4 :Why voltage is only 0.4V and more ?

[thoomanwang]

See schematics, after the plate using Jlink debugging , but found the target voltage is only 0.4V much that I do wrong ?
Battery Voltage : 3.1V
Jlink is intact , use other boards tested.

[thoomanwang · Accepted solution]

Problem solving, is the power supply pin Jlink caused by poor contact。