A plasma cutter has few important items that you need to take care of.
Gas and coolant: Similar to an air conditioner Gas and coolant oil are important for plasma cutters. You need to ensure the plasma cutter has enough gas and coolant and you need to also check to make sure Gas and coolant flow are not affected in any way.
Maintain/replace consumable parts as required: Certain plasma cutter parts need to be replaced after certain wear and tear. If you suspect parts need to be replaced then buy original parts and replace them. Using the right original spares are important for long term effective working of your plasma cutter.
Plasma cutter torch: Your plasma cutter torch can accumulate dirt easily in a few working environments. You need to keep them clean for the quality function of the plasma cutter. Chemicals like Thinner, turpentine oil, Hydrogen peroxide can be used to clear your torch.
Always use experts or expert advice which assembling or disassembling parts. Any mistake can significantly affect the function of the plasma cutter. Good assembling will give a long life for your plasma cutter.