The laser does not work anymore or your instrument computer is fried. You have to get a new one. Like with kitchen appliances or with your household electronics - you just need that part. No questions asked. You call the firm that sold you that piece in the first place. Nowadays it is not the firm that manufactures the parts but some firm with a license to sell it in Europe or on that continent where you're working in. You ask if the part can be repaired cause new one would not be in the budget of your institute and as an environmental scientist you are not keen on throwing material to the waste. A customer service person pics up your call. You get greeted and you explain your problem. You need that part fixed pronto. You think that you get the part repaired. Somewhat later an executive representative with a PhD title contacts you. Don't let that title fool you - it's always the PhDs in that firm that are after your money. In industry PhD does not mean that your science comes first. Yes, we can take a look of your part but that'll cost you and then comes additionally the cost estimate for the repair. But you know that after you pay and send the part for repair cost estimation you'll just receive a recommendation to buy a new one and if you're lucky, they even throw in an offer.
Shopping for science can be frustrating and it does not make it any easier that you have to do it with tax money of other people.