Transformer for X-ray Gun H.V. Power Supply burnt

Mike replaced the IC chips and transistors already, then we send a control signal pulse to measure the SCR output. The waveforms looked well, so I install the SCR controller in the X-ray Anode control box.

We tested the whole system in the afternoon, unfortunately the x-ray gun could not be run correctly. The x-ray anode high voltage was not monitored, while the high voltage connected to the Thyratrons was pretty good. After running a few minutes, I smelled the smoke. Then I found the transform connected between SCR and X-ray anode H.V. power supply was burnt.
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AUTOTRANSFORMER P-8634
Primary ---- Line Cord
230V 50-60Hz

Secondary ---- Receptacle
115V@400VA

STANCOR Chicago, IL