It could need a cap kit, but a common failure on Hantarex monitors is the flyback transformer. Mine started sparking/arcing so it was pretty obvious it was going bad.
It's not that hard to replace with average soldering skills and tools. A solder sucker and/or de-soldering wick is pretty much required.
If he doesn't have soldering skills, any competent TV/Electronics repair shop should be able to diagnose and repair it.
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