E131—-Detect current circuit failure

CUR_A or / CUR_B signal’s zero offset value too large

Troubleshooting steps
Detecting the impedance between the ends of C55/C67 in main control board: 13.5k; using Isolation transformer with 80V to supply power, detect two terminal voltage 1.46v 【means the impedance of U20 foot 1# 、7# to foot 4#(safety line): 13.5k; standby voltage 1.46v】
Detecting the impedance between the ends of C54/C62 in main control board: 100Ω; using Isolation transformer with 80V to supply power, detect two terminal voltage 0v.
Tiltting one end of D8/D11, using multimeter (_→side) to measure the resistance across the diode: Infinity 【Make no mistake when measuring positive and negative】