Infocus IN5110 Projector Ballast Issue - Lamp lights up once out of 15

[thitou]

Hello, I'm currently experiencing a problem with my Infocus IN5110 projector.

Everything works correctly except the lamp lighting. I sometimes have to turn the projector on and off several times (15-20x) to get a lamp strike. I do hear a very short arcing noise each time. I think it's just too weak/short to ignite the lamp.

However, once the lamp decide strikes, the projector lights up correctly and never goes out. So I guess my problem lies in the part of the ballast that manages the initial arc. What do you think?

I checked the communication between the ballast and the motherboard, and the 380v power supply to the ballast. Everything works fine on this side.

I tried another lamp from a working projector, same problem... This one doesn't strike either.

The ballast is definitely defective.

I tried to repair it, checked the transistors, the diodes, no short circuit to report.

As I'm more or less new to power supply repair, I'd like your help with the schematic of this power supply. Here's a image of the schematic (Blue arrow = DC IN 380V -- Yellow arrow = Lamp Out), where is the part responsible for the starting arc? I think it's called the igniter. Do you have any other ideas about the source of the problem?
Perhaps the high-voltage capacitors?

Thank you very much for your answers! Any suggestions would be greatly appreciated!