With a cursory check out of the way, the meat of the work can begin. "Next is onto general checks for the condition of component health, checking fuses, DC-input connectors, power trigger and activation components, whether there is no resistance (direct path) or incredibly low resistance between the voltage supply and ground (short to ground). Some systems will fall into the known faults category where all known service issues are corrected first before moving onto looking for other issues. If no obvious fault is found or known issues are corrected, I move onto powering the system on to observe behaviour. Some issues only appear after the system has been running for a period of time, others can go away after a short amount of time and some are immediate. Issues to do with voltage supply, CPU, RAM and address lines are typically immediately identifiable. Some systems may have issues with custom ICs that require donor parts from other failed systems, or are sadly not repairable. I usually go over any areas that required work under a microscope to ensure that no other faults are waiting to occur within the problem area. Abnormal audio issues and intermittent graphical issues can be a lengthy repair process."