Two ways --
1. Pull the light box and look into the CRT or --
2. Take the screen off and look into the CRT. Myself I would pull the light
box and examine the CRT's to see how much leak out, then check you're power
supply again. Pull the convergence power supply board and check to see if
coolant leak on it. More than likely it has and shorted something on the
board. The convergence pcb is located to right and again check under all
componets.

Coolant is like water and it runs everywhere so check under all the
components where it leak. I had a Mitsubishi not long ago leak on the board
and found coolant under the jungle IC.

Best regards