High Voltage Control Module R03

I checked the R03, measured the signal of pulse modulation H.V. reference voltage (frequency). I have not found anything wrong. The frequency can be tuned from 0 to 10 kHz, which will be converted to voltage 0 to 10 V DC by chip L451 on the C-2154 board. Now we are afraid the feedback or SCR control unit may cause the high current. Mike suggested to send a 800 ms square pulse generated by function generator to test the SCR control unit. If the system running well, we can confirm it's feedback to effect the current. Unfortunately when I installed the circuit board in R03, one leg of the relay K1 accidently was broken. The relay model is Potter & Brumfield R10-E1P4-115V, I have ordered it from OnlineComponents.