SSTC stopped working HELP

[Saattvik24]

I was driving my half bridge sstc based kaizerelectronics sstc 1 on 100 volt AC input on continuous mode, and after a few runs it stopped working and I know it didn't die due to overheating cause I only ran it for short intervals of time and I even had a fan attached to the heatsinks. Now when I power it, it doesn't make any sparks but it faintly lights a cfl when I bring it very close to the top load, so I guess its not completely destroyed. At first I thought I blew up the bridge rectifier because it was only rated for 4 amps so I got a new one rated for 35 amps but it still does the same thing and doesn't work properly. I think the driver works fine and the problem is with the bridge circuit, maybe the mosfets or the half bridge capacitors or the diodes. So I'll be glad if you can help me diagnose it and fix it

[oneKone]

It would help if you could post some pictures.

By the sounds of it you've killed a MOSFET.
You can see if a MOSFET/igbt is dead with a dmm in diode/continuity mode.

[Mads Barnkob]

I agree with oneKone

It sounds like you have one half-/dead MOSFET in your half-bridge. So a small amount of energy is still being pumped/leaked into the primary circuit and it only takes a few Watt of power to make a secondary circuit light up a CFL.

It could even just be your driver circuit coupling energy through the GDT and power the primary circuit from there, I demonstrate that exact behavior in this video where there is no power on the bridge.

[Saattvik24]

I checked both the mosfets and they are both working, so what else could be wrong? When I ran the tesla coil I measured the voltage across both the half bridge capacitors, across one of them was the input voltage and across the other it was only 3 volts, so maybe one of the capacitor is dead???

[davekni]

Any chance you can make some oscilloscope measurements?  A circuit diagram and a few scope captures would help in figuring out what failed.