It is probably not "gross negligence," but even if not at that level, it may well be negligence still--a reasonable person, with notice of frequent electrical problems, would have taken action; and if the first electrician doesn't show, then you call a second one. If the landlord did negligently cause damage to your property, you may be able to sue him for compensation equal to its then value (which may still be less than what it costs to replace, since used electronics are not worth as much as brand new ones; however, any compensation is much better than none). You could retain an attorney to help you, or look to perhaps bring a negligence claim in small claims court yourself, which is quicker and cheaper. Good luck.