What is the most effective way to isolate a microprocessor issue?

Heat injuries are a big reason microprocessors fail, along with overclocking and other adjustments that cause a lot of rigor on processors. CPU isolation techniques are key to determining if the crux of your processing issues are microprocessor related. The basics are power, cooling, and connectivity. Once these are examined and found to be reasonable, then you need to isolate the CPU functionality or pinning specific to CPU cores targeted to specific workload. Failing functional blocks may be culprit to reduced or degrading CPU efficacy. There is some diagnostic software on the market that can help you with further testing. These will typically push the processor and provide measurements like speed, temperature, and stability.

Microprocessors simply control the logic behaviors of a circuit but require firmware code to function. I would advise checking the clock signal and the voltage source pins (the manufacturer documentation helps identify this). Afterwards, check with documentation and the firmware to identify the input and output logic behavioral. Once validated, verify the input and output signals on an oscilloscope (clock signal source, signal timing, logic, etc). In some cases, the microprocessor may be internally damaged/faulty (broken trace viewed via xray machine). If errors persist outside of this spectrum, observing environment of operation where the faults occur may help. Otherwise, issue may be external of the microprocessor.

If you are a bench rat and do a lot of hardware builds, typically you have a lot of testing equipment and experience in component testing. If you aren't and you need to seek out a professional to help you with your $2,000 processor, it may be useful to eliminate as many possible causes ahead of getting an expert involved, $$$$. My recommendation is to contact the vendor who provided your processor and see if they are willing to swap your processor--typically within the first year they are very helpful, but if you have tampered with the processor like overclocking or some kind of other Dr. Frankenstein laboratory foolishness, you may be out of luck! If you are going to tinker with processors I'd start out learning on cheaper hardware.

Build a lab, I know I say this all the time, but it's absolutely critical for building expertise. I know there is a lot of simulation out there which is likely more hospitable and cheaper, but the more you can do hands-on the better. Also, you can try dumpster diving at technology companies (they throw all kind of good stuff away). Second-hand stores like Goodwill, or other thrifting locations get some pretty good technology stuff from time to time and most folks who work at these locations have no idea the IT gold they are sitting on. So check those locations out. Learn how to work with different hardware, componentry, and learn what you can about basic->mid->advanced circuitry. You'd be surprised how far you can get with a multimeter.

No matter what make sure you are working with updated firmware, drivers, etc. Read whitepapers, blogs, and take free training online. A lot of vendors offer free resources on their websites as well. Not much more I think I can add to this portion. It's pretty much SOP, standard operating procedure!

Getting back to a known is the best way forward. Sometimes going back to the beginning is the only way to solve it. Document, document, document what you are doing, when you did it, and this way you can go back to the last known working setting before whatever inconsistencies happened. Now this takes discipline most folks don't have. At home it may not be a big deal, but as a professional, those who document usually have a chair when the music stops and those who don't usually become the scapegoat all the sins of the organization are cast onto and then that scapegoat is sent out into the wilderness to fend for themselves. Don't be the victim because of poor dedication to documentation. Make sure you aren't the one without a chair, document!