Error solution Electromagnet is not working

Trouble shooting procedure
1)Makes sure all electromagnets are not working or just one of them is not working. Q13(cutting), Q14(wiper), Q18(foot lifter), Q19(back sewing) 【same procedure as E151】
2)raise one side of R102, upply power by 80V isolation transformer, test R53 two sides, if the voltage is 27V, is means T1 is working.
Check main board, whether it is in short circuit between foot 1 and foot 3 on Q11.
Check U30 on main board: check impedance between foot 1 and foot 5【ground】:around 33k; voltage:0.7V; check impedance between foot 4 and foot 5【ground】:around 23K; voltage:1.9V; check impedance between foot 6and foot 5【ground】:around 10K; voltage:0V; check impedance between foot 8 and foot 5【ground】:around 8.3K; voltage:5V;

5) check impedance between foot 1 and foot 3【ground】of D10 on main board :around 0.9K; voltage:2.6V; check impedance between foot 2 and foot 3【ground】:infinite; voltage: around 1.8V;