It may well be just an internal fuse but the chances are even if this was true something will of cause the fuse to go, very rarely does a fuse go without a reason, but please don’t poke around inside the monitor even with the mains disconnected because very high tension voltage will be stored.
There are very few services places left nowadays, and you can forget most computer shops they will know all the jargon, but when it comes to fault finding down to component level forget it, if you want it repaired start at the manufactures and ask them if they know of any approved services centres in you’re area, but the cost of computer components drop the moment it’s sold to you so repairs are rarely worth doing and even if it was a simple repair you could kiss goodbye to at least £50+ and also unless a standard component is at fault, spare just will not be available.
Good luck all the best.