My Benq W1090 projector broke. I've discovered and fixed (I think) one hardware fault but the next behavior has me shrugging.
I'd had this projector (hanging upside-down) for about 3,5 years when the green status led stated blinking red upon turning it on. The machine would start up and shutdown again a few seconds later. I lazily 'fixed' this a few times by power cycling the projector and turning it on again... which worked a few times until it didn't anymore. Ultimately upon powering it up the fuses blew in my house! I thought the lamp must be broken, ordered a new one aaaand no, again the fuse blew.
On Youtube I found the brilliant channel FixitFrank and the video below on ballast diagnosis and repair was bang on. 2 out of 4 power mosfets on the ballast board were broken -> short circuit between the legs. The mosfets on this board are
STP30NF20 mosfets. I couldn't find these online and ordered some
SIHP080N60E-GE3 instead. I'm relatively certain that these should be suitable replacements, could anyone here take a look and let me know if I made a mistake here?
I replaced the 2 broken mosfets, reassembled the projector and when I plugged it into the mains... nothing. Absolutely nothing. No blown fuse, that's nice. But also no status leds. I don't quite know what to make of this now.. Could the short circuit in the projector have irreversibly damaged the mainboard? Everything looks fine and clean. I haven't seen any blown caps or burnt IC's. I quite thorougly sniff-tested all boards for burnt smells but also - surprisingly to me - nothing. I really don't know what to try next, hoping for some tips from you. Thank you!